Sarcomas arising in dermatofibrosarcoma protuberans: a reappraisal of biologic behavior in eighteen cases treated by wide local excision with extended clinical follow up

There is a prevailing view that sarcomas arising in dermatofibrosarcoma protuberans (DFSP) have a higher risk of metastasis than ordinary DFSP, but these data are based on cases with variable and often suboptimal treatment. There has not been a large study of sarcomas arising in DFSP in which all cases were treated by wide local excision, thereby arguably altering outcome. Clinicopathologic features of 18 cases of sarcomas arising in DFSP treated by wide local excision and having follow up of at least 5 years were analyzed. An estimate of the proportion of sarcoma and DFSP was made. The number of mitotic figures and degree of CD34 immunoreactivity were assessed in each case. The cohort included 13 females and 5 males (age, 23-87 yrs; median, 47 yrs). The tumors involved the trunk (7), scalp (4), extremities (4), and inguinal region (3), and ranged from 1.5 to 7 cm (median, 4 cm). Sarcoma occurred de novo in 15 cases and in a recurrence in three. Sarcomas resembled fibrosarcoma (17) or malignant fibrous histiocytoma (1) and occupied between 20% and 80% of the tumor (median, 60%). Mitotic activity ranged from 2 to 16 per 10 high-power field (HPF; median 7 per 10 HPF) in the sarcomatous component and 0 to 3 per 10 HPF (median, 1 per 10 HPF) in the DFSP component. All tumors expressed CD34 in the DFSP component but only nine (50%) in the sarcomatous component. All patients were treated by wide local excision with negative margins; three additionally received radiation. Four patients (22%) developed recurrences, but none developed metastasis during the follow-up period of 62 months to 17 years (median, 81.5 mos). In contrast to earlier studies, we demonstrate that patients with sarcomas arising in DFSP do not have an increased risk of distant metastasis within a 5-year follow-up period, provided they are treated by wide local excision with negative margins. This probably reflects the fact that wide local excision results in eradication of local tumor, thereby eliminating the source for subsequent dissemination. However, we cannot completely exclude the possibility that tumors in which clear margins are achieved represent a less aggressive subset, as has been suggested for high-grade extremity sarcomas. Previous studies showing increased metastasis for sarcomas arising in DFSP should be re-evaluated to determine if, with treatment stratification, metastatic rate varies.     

Primary giant cell tumor of soft tissues: a study of 22 cases

Twenty-two cases of giant cell tumor of soft tissues (GCT-ST) identified in the Mayo Clinic files and the consultation files of two of the authors (A.G.N., C.D.M.F.) were analyzed clinicopathologically. Age at presentation ranged from 5 to 80 years (median, 43 years), and there was no sex predilection (12 male, 10 female). Duration of symptoms ranged from 2 to 12 months (median, 4.5 months), and a painless growing mass was the most common complaint. The lower limbs were the most frequent location (50%), followed by the trunk (31.8%) and the upper limbs (13.6%). The size of the tumors ranged from 1 to 10 cm, and they tended to be superficial (86.4%), forming well-circumscribed (72.7%), multinodular (86.4%) masses. Histologically, all tumors consisted of a mixture of mononuclear cells showing vesicular, round to oval nuclei and osteoclastlike, multinucleated giant cells distributed uniformly throughout the tumors. Foci of stromal hemorrhage were observed in 11 tumors (50%); nine tumors (40.1%) showed metaplastic bone formation and six (27.2%) showed aneurysmal bone cystlike areas. Necrosis was absent in all but one tumor. Mitotic figures were present in all but one tumor, ranging from two to more than 30 mitoses per 10 high-power fields (HPFs; median, 9.5 mitoses per 10 HPFs) and were typical in aspect. Vascular invasion was identified in seven tumors (31.8%), and none of the tumors showed marked cellular atypia or pleomorphism. The tumors were treated surgically, and follow-up information was available for 16 patients (duration of follow-up, 2 to 130 months; median, 51 months). Only one of the 16 patients (6.2%) had local recurrence and lung metastases; this patient died of the tumor. In conclusion, GCT-ST occurs as a primary soft-tissue neoplasm and is identical clinically and morphologically to giant cell tumor of bone. Provided that GCT-ST is treated adequately by complete excision, a benign clinical course is expected because episodes of distant metastasis and tumor-associated death seem to be exceedingly rare.     

Gastrointestinal stromal tumors of the stomach: a clinicopathologic, immunohistochemical, and molecular genetic study of 1765 cases with long-term follow-up

Gastrointestinal (GI) stromal tumors (GISTs), the specific KIT- or PDFGRA-signaling driven mesenchymal tumors, are the most common mesenchymal tumors of the GI tract. In this study, we analyzed 1869 cases originally classified as smooth muscle tumors of the stomach and found that 1765 (94%) of these were GISTs. The GISTs had a slight male predominance (55%) with a median age of 63 years. Only 2.7% of tumors occurred before the age of 21 years and 9.1% before the age of 40 years. The tumors varied from 0.5 to 44 cm (median, 6.0 cm) and most commonly presented with GI bleeding; 12% were incidentally detected. Several histologic variants were recognized among the spindle cell tumors (sclerosing, palisaded-vacuolated, hypercellular, and sarcomatous) and of epithelioid tumors (sclerosing, dyscohesive, hypercellular, and sarcomatous). Outcome was strongly dependent on tumor size and mitotic activity. Only 2% to 3% of tumors <10 cm and <5 mitoses/50 HPFs metastasized, whereas 86% of tumors >10 cm and >5 mitoses/50 HPFs metastasized. However, tumors >10 cm with mitotic activity <5/50 HPFs and those <5 cm with mitoses >5/50 HPFs had a relatively low metastatic rate (11% and 15%). A small number of patients survived intra-abdominal metastasis up to over 20 years. Tumor location in fundus or gastroesophageal junction, coagulative necrosis, ulceration, and mucosal invasion were unfavorable factors (P <0.001), whereas tumor location in antrum was favorable (P <0.001). KIT expression was detected in 91% of the cases, CD34 in 82%, smooth muscle actin in 18%, and desmin in 5%; the latter two were favorable (P <0.001). KIT exon 11 mutations were detected in 119 cases; patients with point mutations fared better than those with deletions (P <0.01). PDGFRA exon 18 mutations (total 86 cases) were common in epithelioid GISTs and most commonly represented a D842V point mutation; none of these was prognostically significant. The above results may be helpful for setting the criteria for adjuvant treatment such as Gleevec.     

Myxoid dermatofibrosarcoma protuberans: a rare variant analyzed in a series of 23 cases

The myxoid variant of dermatofibrosarcoma protuberans (DFSPs) is uncommon. It often presents a diagnostic challenge and is important to recognize to prevent both undertreatment and overtreatment. To better characterize this unusual variant of DFSP, 23 myxoid DFSPs (DFSP with greater than 50% myxoid stroma) were retrieved from the authors' consult files. 13 patients were male and 10 were female (median age 40 years; range 9 months to 72 years of age). Tumor size ranged from 1.5 to 11 cm (median 2.8 cm). The most frequent sites were the extremities (9) and head and neck (7), followed by the trunk (4) and anogenital region (3). Grossly, the tumors were white/tan/gray to yellow, firm to gelatinous soft tissue masses. Histologically, tumor stroma ranged from 50 to 100% myxoid (median 80%). The majority of cases displayed an infiltrative sheet-like proliferation of bland spindle cells with palely eosinophilic cytoplasm and stellate nuclei without pleomorphism. The stroma was myxoid with prominent thin-walled vessels. All cases displayed honeycomb infiltration of fat and 16 cases showed cellular areas of more typical DFSP. Four tumors contained pigmented dendritic cells (Bednar variant), 1 showed areas of giant cell fibroblastoma and 1 showed progression to fibrosarcomatous DFSP. Mitoses ranged from 0 to 5 per 10 high power fields. 95% of cases (21 out of 22) were positive for CD34 and all cases were negative for S100 and muscle markers. Clinical follow-up in 8 cases, ranging from 3-21 years, (median follow-up 6 years), revealed local recurrence in 2 cases and no evidence of metastasis. All patients were free of disease following wide excision or excision followed by radiotherapy. In summary, these low-grade lesions are clinically similar to typical DFSP, but their unusual morphology is easily confused with a variety of other tumor types.     

Fibrosarcomatous change in dermatofibrosarcoma protuberans

This report describes six patients with dermatofibrosarcoma protuberans (DFSP) that contained fibrosarcomatous areas (FS). The clinical signs and symptoms, ages of the patients, and anatomic distribution of the tumors were similar to those of uncomplicated DFSP. FS was concentrated in the subcutis in each case and comprised more than 50% of the tumor in four cases. The characteristic storiform cellular arrangement of DFSP was replaced by long, gently sweeping fascicles of spindle cells that intersected at various angles, forming the so-called herringbone pattern. Trapped fat cells, characteristic of DFSP when it infiltrates subcutaneous tissue, were absent in five of the six FS and only focally present in one. Two FS were grade 1; their cytologic features were similar to those of DFSP. Four FS were grade 2 and had cytologic atypia exceeding that of DFSP. There was a statistical difference between the mitotic rates of DFSP and FS. Five patients were alive and well at the time of last follow-up (median, 2 years), and one patient had an unexcised recurrence when last examined. Six similar cases from the literature are reviewed; in one of them, the FS metastasized.     

Ossifying fibromyxoid tumor of soft parts--a clinicopathologic and immunohistochemical study of 104 cases with long-term follow-up and a critical review of the literature

Ossifying fibromyxoid tumor (OFT) is a unique soft tissue tumor of uncertain histogenesis. The majority of reported cases (approximately 220) have pursued a benign clinical course. However, recent literature has emphasized the existence of morphologically atypical and clinically malignant examples of this tumor and proposed guidelines for assessment of biologic potential. In the present study, we evaluated 104 cases of OFT from the Armed Forces Institute of Pathology, accessioned between the years 1970 and 2007. Herein, OFT was strictly defined as a tumor with lobular architecture, predominantly epithelioid cell morphology, a low level of atypia, corded and trabecular growth patterns, moderate amounts of myxocollagenous matrix, and often, focal peripheral metaplastic bone formation. Tumors that lacked conventional morphology were excluded. The exclusion group included cutaneous mixed tumors, low-grade fibromyxoid sarcomas, and extraskeletal osteosarcomas. The OFTs occurred in 64 men and 40 women with a median age of 50 years (range, 21 to 81 y). The tumor size ranged from 0.7 to 17 cm (median, 3 cm). The mitotic rate varied from 0 to 41 mitotic figures per 50 HPFs (median, 2/50 HPFs). Tumor cell nuclei typically contained small, distinct nucleoli, and necrosis was infrequent (11/104). The great majority of tumors (67/71, 94%) were positive for S100 protein, whereas only occasional examples had (focal) positivity for desmin, glial fibrillary acidic protein, and an AE1/AE3 keratin cocktail. Local recurrences were documented in 9 of 41(22%) living patients, usually 10 or more years after primary surgery, but there were no metastases. A mitotic rate of >2 mitotic figures/50 HPFs was a risk factor for local recurrence, but necrosis, tumor size, the presence of satellite nodules, and positive margins were not. When OFT is strictly defined by the criteria noted above, there is potential for local recurrence, but there seems to be little or no risk for metastasis.     

True smooth muscle tumors of the small intestine: a clinicopathologic, immunhistochemical, and molecular genetic study of 25 cases

Gastrointestinal stromal tumors (GISTs) comprise a great majority of small intestinal mesenchymal tumors previously designated as smooth muscle tumors (SMTs), but true SMTs occur with a low-frequency encompassing both leiomyomas and leiomyosarcomas (LMSs). In this study, we analyzed 25 tumors in the spectrum of primary SMTs of the small intestine. Metastatic tumors and those with external attachment only were excluded. These tumors occurred in 15 men and 10 women of median age of 62 years (range: 18 to 80 y). There were 9 well-differentiated SMTs with no atypia and low mitotic activity [< or = 5/50 high-power fields (HPFs)] and these were considered leiomyomas. All 6 tumors examined were positive for SMA and desmin, and negative for KIT; all 3 tumors in female patients that were tested were negative for estrogen receptor. Two leiomyomas, a 5 mm, and another, 2 cm tumor, were examples of a muscularis mucosae leiomyomas. The other 7 were considered intramural leiomyomas; their median diameter was 4.5 cm (range: 0.8 to 9 cm). No patient with these tumors experienced recurrences or metastases, and 6 patients were alive with a median follow-up of 16 years (range: 9 to 28 y). Sixteen tumors had atypia and mitotic activity warranting the designation of LMS. One of these tumors, a 16 cm diverticular tumor, had mitotic activity of only 1/50 HPFs, and this tumor recurred 4 times. All other LMSs had > or =35 mitoses/50 HPFs. Four of 5 such LMSs with follow-up recurred or metastasized, and at least 3 patients died of disease; several others had a short survival but cause of death could not be determined. One patient, an 18-year-old woman, who died of LMS, was a survivor of a Wilms tumor radiated in infancy. All 6 LMSs studied for GIST-specific KIT and platelet-derived growth factor receptor alpha mutations showed wild-type sequences. This series demonstrates that primary small intestinal SMTs are rare (estimated frequency 1 SMT for 36 GISTs). A majority of these are mitotically active tumors with atypia warranting the diagnosis of LMS, and have a high malignant potential. The number of LMS cases is too small for stratification for risk assessment. True SMTs of small intestine should be separated from GISTs because of different pathogenesis and treatment.     

头皮复发性隆突性皮肤纤维肉瘤的外科治疗

目的 探讨头皮复发性隆突性皮肤纤维肉瘤（dermatofibrosarcoma protuberans,DFSP）的外科治疗方法和效果.方法 对近3年收治的7例头皮复发性DFSP患者行回顾性分析.肿瘤术中先行活检做冰冻切片病理检查,确认为阳性病例后行距肿瘤边缘≥3 cm的扩大切除术,基底深部的颅骨组织如亦被侵及,一并做颅骨外板清除或全层颅骨切除.切除标本再次行术中冰冻切片病理检查,证实切缘和基底肿瘤阴性后,继发创面行皮瓣/筋膜组织瓣转移修复.肿瘤标本于术后行HE常规染色和免疫组织化学等病理检查.结果 7例肿瘤标本,术中冰冻切片病理检查和术后病理检查均证实为DFSP复发.7例均行≥3 cm的扩大切除,同时做颅骨切除,其中5例行颅骨外板清除,另2例做颅骨全层切除.术中冰冻切片病理和术后病理报告均证实切缘干净,免疫组织化学病理诊断显示肿瘤组织Ki-67均为阳性,CD34部分阳性.术后随访15～41个月,均未见肿瘤局部复发和远位转移.结论 扩大切除及彻底清除被肿瘤侵及的颅骨是头皮复发性DFSP有效的治疗方法,能减少术后复发;皮瓣转移技术的应用有助于肿瘤完全切除后的创面妥善修复.     

Synovial sarcoma of the extremities: a clinicopathologic study of 34 cases, including semi-quantitative analysis of spindled, epithelial, and poorly differentiated areas

Many clinicopathologic studies of synovial sarcoma have grouped together tumors from different sites. The goal of this study was to identify clinical and pathologic features that correlate with a poor outcome in patients with extremity synovial sarcoma. Thirty-four cases of synovial sarcoma of the extremities were studied. Inclusion criteria included a consistent histology, the immunohistochemical expression of at least one epithelial marker (AE1/3, CAM 5.2, or epithelial membrane antigen), and adequate clinical follow-up. Features evaluated included the presence and extent of spindled, epithelial, and poorly differentiated areas, the presence and extent of calcification and necrosis, nuclear grade, the presence or absence of cells with a rhabdoid morphology, and the number of mitotic figures (MFs) per 10 high power fields (HPFs). Patients were considered to have an adverse outcome if they developed metastatic disease or died from tumor. The cohort included 15 males and 19 females with a median age 36 years (range, 11-82 years). There were 22 lower extremity tumors and 12 located on the upper extremities. Tumor size ranged from 1.2 to 16 cm (median, 6 cm). Follow-up ranged from 9 to 108 months (median, 38 months). Eleven (32%) patients had an adverse outcome, all with metastatic disease. Features associated with an adverse outcome included increasing age (p = 0.04), tumor size of 5 cm or greater (p = 0.03), tumor location on the lower extremities (p = 0.04), the presence of poorly differentiated areas (p = 0.04), grade 3 nuclei (p = 0.005), cells with a rhabdoid morphology (p = 0.003), and more than 10 MFs/10 HPFs (p = 0.005). Patients whose tumors were composed of at least 20% poorly differentiated areas were significantly more likely to have an adverse outcome (p < 0.001). In conclusion, a variety of clinical and pathologic features are associated with an adverse outcome in patients with synovial sarcoma of the extremities. These features include increasing age, tumor size of 5 cm or more, lower extremity tumor location, the presence of poorly differentiated areas, particularly when at least 20% of the tumor, grade 3 nuclei, rhabdoid cells, and more than 10 MFs/10 HPFs.     

隆凸性皮肤纤维肉瘤的临床诊治

目的 进一步提高对隆凸性皮肤纤维肉瘤(DFSP)的认识,强调正确和规范化手术的重要性,并探讨综合治疗途径。方法 对1985年1月至2002年9月收治的163例DFSP病例,进行临床和病理资料的回顾性分析。结果 163例患者中有150例(占92．0%)曾被误诊为良性肿瘤而行局部切除手术,经补充广泛切除、病理检查最终明确局部有肿瘤残留者69例,占46．0％,其中49例(占71．0％)在体检或B超检查时未能发现残留灶。局部切除术后,肿瘤复发率可达45．1％,明显高于广泛切除术后复发率(5．6％)。在施行广泛切除手术的142例患者中,有99例皮肤切缘≥3cm,术后局部复发5例(5．1％),36例皮肤切缘在1∽2em,术后复发3例(8．3％)。46例(32．4％)行游离植皮,11例行筋膜皮瓣转移,1例行缺损区涤纶修补。术后的并发症主要是移植皮瓣的坏死(20例)和切口感染(6例),但术后2个月内均能治愈。有17例患者因为曾经多次复发或广泛切除术后病理报告明确切缘或基底仍有肿瘤细胞残留而补充放射治疗,放射量3275∽7000cGy。放疗后有1例患者出现湿性蜕皮,局部复发2例。在全部病例中,只有2例(1．2％)死亡,其中1例死于肺、肝转移;另有2例曾出现区域淋巴结转移,经手术治疗后存活至今。有13例(占8．0％)出现纤维肉瘤样改变(DFSP-FS),其恶性程度增加,其中11例见于局部复发的病例。结论 在局部切除术后,一经病理检查确诊为DFSP,必须施行补充广泛切除以避免肿瘤残留;规范化的广泛切除是治疗DFSP、降低复发率的主要方法;对术后切缘阳性、身体状况不适合手术治疗的患者辅以放射治疗仍不失为一种有效的治疗方法;对DFSP-FS,临床医师必须引起重视并采用更积极的治疗方案。     

Dermatofibrosarcoma protuberans. A clinicopathologic review with emphasis on fibrosarcomatous areas.

We reviewed 75 cases of dermatofibrosarcoma protuberans (DFSP) from the University of Texas M.D. Anderson Cancer Center. All accessions were examined for areas of giant cell fibroblastoma (GCF), but none was found. The 30 cases having a minimum of 5 years follow-up were studied in more detail. The histologic findings were typical of DFSP in 24 cases, whereas in six cases discrete areas with a fascicular or "herringbone" growth pattern, considered to represent fibrosarcomatous change (DFSP-FS), were evident. The mitotic rate was usually but not always higher in fibrosarcomatous areas, and occasional examples of typical DFSP demonstrated relatively numerous mitotic figures (up to 35 per 10 high-power fields). Other histologic findings of interest were the presence of melanin in two cases of DFSP and the focal presence of a distinctive type of multinucleated giant cell similar to those seen in GCF in six cases. Patients with DFSP-FS differed from those with DFSP in that they had a higher median age (56 years vs. 37 years). Tumor location was similar in both groups, with the trunk being the most common site. No significant difference in either the rate of local recurrence or the interval until recurrence between DFSP and DFSP-FS was evident; the only factor strongly related to local recurrence was adequacy of surgical margins. However, the only two patients who died of tumor, including the sole patient with distant metastasis, had DFSP-FS. We conclude that DFSP-FS deserves recognition as a variant of DFSP.     

Fibroepithelial Lesions in the Breast of Adolescent Females: A Clinicopathological Study of 54 Cases

Fibroepithelial lesions (FELs) are the most frequent breast tumors in adolescent females. The pubertal hormonal surge could impact the growth and microscopic appearance of FELs in this age group. In this study, we evaluate the morphology and clinical behavior of FELs in adolescents. We searched the 1992–2012 pathology data base for FELs in females 18 years old or younger (F ≤18 years). Seven FELs from 1975 to 1983 were also included. Three pathologists reviewed all available material. Patient (pt) characteristics and follow‐up information were obtained from electronic medical records. Forty‐eight F ≤18 years had 54 FELs with available slides. Thirty (67%) pts were Caucasian, 12 (27%) African‐American, two (4%) Hispanic, one (2%) Asian; three were of unknown race/ethnicity. Median age at diagnosis was 16 years. Median age at menarche was 12 years; most (96%) FELs occurred after menarche (median interval 48 months). All patients underwent lumpectomy; one required subsequent mastectomy. The FELs were 34 fibroadenomas (FAs) (11 usual, 23 juvenile), and 20 phyllodes tumors (PTs) (16 benign, one borderline and three malignant). Eight (35%) juvenile FAs showed slight intratumoral heterogeneity. The mean mitotic rate was 1.3 mitoses/10 high‐power fields (HPFs) (range, 0–6) in usual FAs, 1.8/10 HPFs in juvenile FAs, 3.1/10 HPFs in benign PTs, 10/10 HPFs in the borderline PT and 17/10 HPFs in malignant PTs. The mean follow‐up for 29 pts with 33 FELs was 44 months. Two (10%) PTs recurred locally (a benign PT at 18 months, and a borderline PT at 11 months). Both recurrent PTs had microscopic margins <1 mm. Mitotic activity in FAs from adolescents can be substantial and this finding should be interpreted cautiously. Awareness of the morphologic features of FELs in adolescents is important to avoid overdiagnosis of PTs, which can lead to additional unnecessary and potentially disfiguring surgery.     

Cellular angiofibroma: clinicopathologic and immunohistochemical analysis of 51 cases

Cellular angiofibroma is a recently described histologically distinctive benign mesenchymal neoplasm composed of 2 principal components, the cellular spindle cell component and prominent stromal blood vessels. Cases in males have sometimes been called "angiomyofibroblastoma-like tumor." We describe a series of 51 cases of cellular angiofibroma to further characterize its clinicopathologic and immunohistochemical features. There were 26 women and 25 men, ranging in age from 22 to 78 years (mean 53.5, median 52 years). Men tended to be older than women. Tumor size ranged from 0.6 to 25.0 cm (overall median size 3.9 cm, median in women 2.7 cm, median in men 6.7 cm). Most common sites were the vulvovaginal region (22 cases) and the inguinoscrotal region (19 cases). Preoperative duration (known for 25 patients) ranged from 1 week to 5 years, with presentation as a painless mass, except for 1 case each with intermittent genital bleeding and a painful mass. Most lesions were located primarily in subcutaneous tissue. Most cases were grossly well marginated. Two cases showed foci of hemorrhage and 1 case showed foci of necrosis. Microscopically, 41 tumors were well circumscribed, and 2 tumors infiltrated into the surrounding tissue. All tumors consisted of bland, spindle-shaped cells, short bundles of wispy collagen and numerous small- to medium-sized thick-walled vessels. Intralesional fat was present in 12 cases (6 female and 6 male cases). Mild cytologic atypia (5 cases) and frequent mitoses (3 cases) were infrequent; significant nuclear atypia and abnormal mitoses were absent. By immunohistochemistry, 29 of 48 tumors (60%) expressed CD34, 10 of 48 (21%) SMA, 4 of 48 (8%) desmin, but none expressed S-100 protein. Follow-up information was available for 40 patients (range 4-168 months; mean 31.2 months) and no patient has developed recurrence or metastasis to date.     

Malignant fat-forming solitary fibrous tumor (so-called "lipomatous hemangiopericytoma"): clinicopathologic analysis of 14 cases

Fat-forming solitary fibrous tumor is a rare variant of solitary fibrous tumor (SFT). Generally regarded as benign, very few fat-forming SFTs with malignant histologic features have been reported. Here, we report 14 histologically malignant fat-forming SFTs to better characterize this subset. Seven patients were female and 7 were male, with ages ranging 20 to 93 years (median, 57 y). Five tumors were located in the lower limb, 3 in the trunk, 3 in abdominopelvic locations, 2 in the head and neck region, and 1 in the upper limb. The tumor size ranged from 3.4 to 20 cm (median, 8.6 cm). Histologically, all exhibited at least focal hypercellularity; 12 tumors had mitoses >4/10 high-power fields (range, 2 to 37; median, 8), 12 showed at least moderate atypia, and 8 showed necrosis. It should be noted that 7 tumors contained only mature adipose tissue, whereas 5 contained multivacuolated lipoblasts and 2 had areas resembling atypical lipomatous tumor (ALT). Immunohistochemically, CD34 and CD99 were positive in most cases (11 of 14 and 8 of 10, respectively); MDM2 and CDK4 were both negative in all 4 cases tested (including both tumors with ALT-like areas). Follow-up data from 10 cases (median duration, 47.5 mo; range, 5 to 76) showed 2 patients with multiple metastases (both to lung and bones, and 1 each to breast and to soft tissue), both of whom died of disease. In conclusion, fat-forming SFTs exhibiting malignant histologic features have potential for aggressive behavior. The presence of lipoblasts and/or ALT-like areas, although described in some "benign" examples of fat-forming SFT, seems much more common in the malignant subset and may prompt a careful search for morphologic evidence of malignancy in any case of fat-forming SFT.     

Cellular fibromas of the ovary: a study of 75 cases including 40 mitotically active tumors emphasizing their distinction from fibrosarcoma

Cellular fibroblastic tumors of the ovary are currently classified as either cellular fibroma (CF) or fibrosarcoma. The former are characterized by bland nuclei, 3 or fewer mitotic figures per 10 high-power fields (MFs/10 HPFs), and a low malignant potential, whereas fibrosarcomas usually have severe nuclear atypia, > or = 4 MFs/10 HPFs, and an aggressive clinical course. The prognosis of cellular fibromatous tumors with > or = 4 MFs/10 HPFs and low-grade cytology is not established and it is the purpose of this study to investigate that aspect. It has been our anecdotal experience that otherwise typical CFs with > or = 4 MFs/10 HPFs usually have a benign clinical course, suggesting that such tumors should be regarded as "mitotically active cellular fibroma" (MACF) rather than fibrosarcoma. Seventy-five cellular fibromatous neoplasms were analyzed to determine their clinicopathologic features and the appropriateness of "MACF" as a designation for otherwise typical CFs with > or = 4 MFs/10 HPFs. The mean age of patients with CF (n = 35, 0 to 3 MFs/10 HPFs) and MACF (n = 40, > or = 4 MFs/10 HPFs) was 51 and 41 years, respectively. Patients most commonly presented with symptoms related to a pelvic mass. All tumors were unilateral. The mean tumor size of CFs was 8.0 cm and 9.4 cm for MACFs. The majority of the tumors were solid; approximately one-third of them had a cystic component. Ovarian surface adhesions, involvement of the ovarian surface, or both, was present in 6% of CFs and 10% of MACFs. Eleven percent of CFs and 13% of MACFs were associated with extraovarian involvement. All tumors consisted of cellular, intersecting bundles of spindle cells with bland nuclear features. The mean highest mitotic count for MACFs was 6.7 MFs/10 HPFs (range 4 to 19 MFs/10 HPFs). Follow-up of 3 months to 12 years (mean 4.75 y) was available in 18 of the 40 patients with MACFs and was uneventful in all cases. We conclude that cellular fibromatous neoplasms with bland cytology and elevated mitotic counts are associated with favorable patient outcome and should be diagnosed as MACF rather than fibrosarcoma, which usually have moderate to severe atypia and elevated mitotic rates. As prior observations have shown that even typical CFs can occasionally recur locally, particularly if they are associated with rupture or adherence, long-term follow-up for patients with CFs and MACFs is appropriate.     

Clinicopathologic Prognostic Factors in Myxoid Liposarcoma: A Retrospective Study of 49 Patients With Long-Term Follow-Up

BACKGROUND: The main goal of this retrospective study was to investigate prognostic factors influencing the survival of myxoid liposarcoma (MLS) with emphasis on the role of transitional areas (TLS) and round cell morphology (RCLS). METHODS: From 1977 to 2004, 49 patients-28 men (57%) and 21 women (43%) with a median age of 44 years (range, 7-83 years)-were diagnosed with an MLS. In 42 patients, the histology could be reviewed, and tumors were classified as MLS, TLS, or RCLS. Clinicopathologic factors were analyzed for influence on survival by univariate and multivariate methods. RESULTS: The median follow-up of 49 patients was 101 months (range, 4-550 months). Of the 42 patients for whom histology was reviewed, 16 tumors were classified as MLS (38%), 19 as TLS (45%), and 7 as RCLS (17%). Sixteen patients (33%) developed a local recurrence after a median follow-up of 21 months (range, 2-108 months). Thirteen patients (27%) developed metastases. The median interval between diagnosis and metastasis was 41 months (range, 0-222 months). Median survival after metastasis was 18 months (range, 1-179 months). The 5- and 10-year disease-specific survival rates were 85% and 72%, whereas the 5- and 10-year overall survival rates were 83% and 68%, respectively. Age at presentation (P = .02), tumor grade (P = .01), and tumor size (P = .005) were significant prognostic factors associated with survival. Tumor grade was the only independent prognostic variable that remained significant with multivariate analysis. A TLS presentation had no negative influence on patient survival. CONCLUSIONS: Age at presentation, tumor grade, and tumor size had a negative influence on survival by univariate analysis, whereas tumor grade was the only independent prognostic factor by multivariate analysis. TLS was not associated with poor outcome.     

Sentinel Lymph Node Biopsy in Histologically Ambiguous Melanocytic Tumors With Spitzoid Features (So-Called Atypical Spitzoid Tumors)

Background The distinction of Spitz nevi from melanomas with spitzoid morphology can be difficult. For lesions with overlapping histopathologic features, it may be impossible to predict their malignant potential with certainty. The current study evaluated the role of sentinel lymph node (SLN) biopsy in patients with such atypical spitzoid tumors. Methods The clinical and histopathologic features of 21 patients with atypical spitzoid tumors who underwent SLN biopsy were reviewed and correlated with the presence or absence of metastatic tumor in their corresponding SLNs. Results The atypical histopathologic features that were most frequently present included incomplete maturation (11 patients, 52%), two or more dermal mitoses per square millimeter (13 patients, 62%), and deep dermal mitoses (11 patients, 52%). Six patients (29%) showed SLN metastasis. There were histopathologic differences between tumors with positive SLN when compared with tumors with negative SLN: mean tumor thickness (3.38 mm vs. 2.04 mm), incomplete maturation (83% vs. 40%), median dermal mitotic rate (3.5/mm² vs. 2/mm²), deep dermal mitoses (83% vs. 47%), and expansile dermal nodules (50% vs. 13%). However, of these, only the difference in mean tumor thickness reached statistical significance (P < .05). Conclusions SLN biopsy offers a means of assessing the metastatic potential of atypical spitzoid tumors and aids in the management of these patients by selecting patients who may benefit from a regional node field dissection and those in whom the use of adjuvant therapies could be considered.     

A rare variant of scalp dermatofibrosarcoma protuberans: malignant fibrous histiocytomatous transformation

Dermatofibrosarcoma protuberans (DFSP) is a relatively uncommon, local aggressive tumor. Tumor metastasis is rare, and it has equal sex distribution. DFSP usually develops on the trunk and extremities. Scalp DFSP composes less than 5% of all cases. Local recurrence rates are high. Wide local excision and Mohs surgery are options for treatment. Fibrosarcomatous or malignant fibrous histiocytomatous transformation of DFSP are rare conditions. In this article, we described a case of a giant DFSP over the scalp containing malignant fibrous histiocytomatous transformation areas.