Myxoid dermatofibroma

AIMS: This report presents seven cases of a rare variant of dermatofibroma, characterized by marked mucinous stromal changes. METHODS AND RESULTS: In this retrospective clinicopathological study, lesions preferentially occurred on the lower extremities of young to middle-aged females. Clinical (differential) diagnoses included: dermatofibroma (two cases), cyst, tophus, ganglion and neurofibroma. Histology revealed well circumscribed, faintly stained dermal to subcutaneous lesions which contained abundant stromal mucin. A variable amount of spindle-shaped cells, occasional lymphocytes and fine collagen fibres were also seen. Epidermal hyperplasia above as well as storiform arrangement of spindle cells and some sclerotic collagen at the periphery of the lesion indicated the fibrohistiocytic origin. Individual histopathological features included: bizarre giant cells, perifollicular arrangement and seas of mucin with pseudovascular clefts in one case each. Immunohistochemically, all lesions were positive for KiM1p (> 50% of the cells). Moreover, two lesions showed moderate reactivity for factor XIIIa (10-25%), one each with NK1C3 (> 90%) and smooth muscle actin (50%), but were otherwise negative with a broad panel of markers. Electron microscopy in one case revealed large pools of mucin interspersed by a moderate number of fibrocytes with fine fibrillary collagen. CONCLUSION: This series confirms myxoid dermatofibroma as a rare variant of fibrohistiocytic tissue response; our series also indicates that many of these lesions might be misinterpreted as cutaneous myxoma.     

Superficial Acral Fibromyxoma: Immunohistochemical and Ultrastructural Analysis of a Case,with Literature Review

ABSTRACT

Superficial acral fibromyxoma (SAFM) is an uncommon tumor of the superficial soft tissues of acral sites. SAFM is a proliferation of fibroblastic cells, within a myxoid to collagenous stroma. The published cases mostly expressed immunoreactivity for CD34, CD99, EMA, and, less frequently, CD10. The authors report an additional case that did not express any of the previously reported markers, including CD34, and antigens of mesenchymal stromal lineage. Ultrastructural study confirmed the tumor cells were typical fibroblasts with cytoplasmic intermediate filaments and numerous cisternae of rough endoplasmic reticulum. The authors describe the first example of SAFM, ultrastructurally studied, with pure fibroblastic immunoprofile.     

Myxoid variant of adrenocortical carcinoma: report of a unique case

Myxoid variant of adrenocortical carcinomas (ACC) are rare, there being only 11 cases in the literature to date. Reported herein are the findings of a case, which in contrast to all previously reported myxoid ACC, was devoid of typical non-myxoid areas. The patient was a 61-year-old man in whom a left adrenal mass was detected during investigation of Cushing's syndrome. The adrenal was replaced by malignant cells and expanses of myxoid material. The cells were positive for melan-A, synaptophysin, vimentin and alpha-inhibin. The ultrastructural features of the cells were typical of adrenal cortical differentiation. The differential diagnosis of myxoid ACC includes extraskeletal myxoid chondrosarcoma, chordoma, myxoid adenocarcinoma, myxoma, lipomatous tumors, nerve sheath tumors, smooth muscle tumors, gastrointestinal stromal tumor and other sarcomas. The presence of myxoid material in a retroperitoneal lesion raises a broad differential diagnosis in which myxoid adrenocortical neoplasms should be included. Clinicoradiological correlation may be helpful, but special stains, immunohistochemistry and ultrastructural examination may be necessary to establish the diagnosis.     

Myxoid liposarcoma: a case report of a sentinel metastasis to the parotid gland with molecular confirmation

Myxoid liposarcoma is a subtype of liposarcoma with a predilection for the deep soft tissues of the extremities that accounts approximately for 10% of all adult soft tissue sarcomas. We report a case of a metastatic myxoid liposarcoma to the parotid gland, with fine-needle aspiration cytology correlation and molecular characterization. The lesion was diagnosed in a 53-year-old Hispanic male who presented with a left posterior thigh mass. A core needle biopsy established the diagnosis of myxoid liposarcoma. The patient underwent limb-sparing, wide local excision of the malignancy and later presented with an initial metastatic lesion to the parotid gland. The diagnosis of metastatic myxoid liposarcoma was rendered by fine-needle aspiration cytology with cell block preparation, and molecular confirmation. Although myxoid/round cell liposarcomas are classically described as having minimal pleomorphism on cytologic material, we encountered significant pleomorphism in our case. Therefore, a diagnosis of myxoid/round cell liposarcoma should still be a diagnostic consideration even if markedly pleomorphic cells are seen in fine-needle aspiration biopsies.     

Myxoid epithelioid sarcoma: a diagnostic challenge. A report on six cases

Flucke U, Hulsebos T J M, van Krieken J H J M & Mentzel T
(2010) Histopathology 57 , 753–759
Myxoid epithelioid sarcoma: a diagnostic challenge. A report on six cases Aims: Epithelioid sarcoma (ES) is a distinct sarcoma‐type with a specific morphology and immunophenotype. Whereas focal myxoid change does occur, to our knowledge only two cases of ES with diffuse myxoid stroma have been reported previously. To characterize more clearly the myxoid variant of ES, we describe six additional cases and discuss the differential diagnoses. Methods and results: Cases were retrieved from the authors’ files and studied histologically, immunohistochemically and by molecular methods. The age of the patients, four females and two males, ranged from 16 to 74 years (median: 33 years). The neoplasms arose in an extremity (two cases), the abdominal wall, groin, perineum and shoulder (one case each). Histologically, four cases were of the conventional type, and two were of the proximal type and the immunophenotype was typical for ES. The tumour stroma, however, revealed prominent myxoid changes, ranging from 50 to 90% (median: 75%). Only one of the proximal type ES showed a SMARCB1 mutation, whereas the other tumours showed no mutation. Conclusions: The myxoid variant of ES represents a diagnostic challenge and may be confused with other benign and malignant myxoid neoplasms. The main differential diagnosis is myoepithelioma of the skin and soft tissue.     

Myxoid liposarcoma of the breast in a 25-year-old female as a diagnostic pitfall in fine needle aspiration cytology: report of a rare case

Primary sarcomas of the breast are extremely rare comprising less than 1.0% of all malignant tumors of the breast. It is even rarer to be reported in a 25-year-old female. This can cause a diagnostic dilemma not only for the clinician but also for the cytopathologist. A 25-year-old woman presented with a well defined firm, mobile lump in her right breast. With fine needle aspiration cytology (FNAC) and ultrasonography a diagnosis of fibroadenoma was made. The patient underwent lumpectomy. Histopathologically it was diagnosed as myxoid liposarcoma. This case is reported to highlight the fact that, even though rare in young females but the possibility of a breast lump being a myxoid liposarcoma does exist. This report discusses a primary myxoid liposarcoma of female breast, considers cytologic differential diagnoses with review of the relevant literature.     

T细胞淋巴瘤伴黏液间质1例及文献复习

目的 报道1例罕见的臀部伴黏液间质的T细胞淋巴瘤并文献复习,探讨其诊断要点。方法 应用组织学、免疫组化、基因重排检测技术进行诊断与鉴别诊断。结果经多项免疫组化排除了软组织肿瘤（纤维、平滑肌、横纹肌、脂肪、滑膜肉瘤及肌纤维母细胞瘤）及恶性黑色素瘤等以后,进行了淋巴瘤标记：CD45、CD45RO、CD3、CD20、CD79α、CD68、和TCRγ基因重排检测。显示CD45、CD45RO、CD3阳性,TCRγ克隆性基因重排。结论 本例与文献报道4例资料提示：伴黏液间质的非霍奇金淋巴瘤好发于淋巴结外软组织,由弥漫性淋巴瘤样片状区与黏液间质区组成,必需应用免疫组化排除间叶源性肿瘤,加用淋巴瘤标记和基因重排检测阳性确诊。     

Sarcomatoid hepatocellular carcinoma with chondroid variant: case report with immunohistochemical findings

A case of sarcomatoid hepatocellular carcinoma (HCC) with a chondroid variant in a 72-year-old woman is reported. Histologically, the tumor consisted of typical HCC of adult type, with an adenocarcinoma-like structure and a sarcomatoid component containing multinodular chondroid foci. Transition from carcinoma to sarcomatoid component was observed. The cells containing mucus were extremely few in adenocarcinoma-like structures. Immunohistochemically, other than typical HCC, some of the chondroid cells, adenocarcinoma-like cells and sarcomatoid cells were positive for alpha-fetoprotein.     

Fine‐needle aspiration cytology of extraskeletal myxoid chondrosarcoma: A case report

Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue tumor arising in extremities. We report a typical case of EMC in left inguinal region of a 71‐year‐old man, which was first approached by fine‐needle aspiration, followed by surgical excision and subsequently diagnosed by microscopic examination and immunohistochemical study. We discuss briefly the differential diagnosis. It is important to separate EMC from other myxoid soft tissue tumors. We point out that although cytologic features may be orientating to a myxoid tumor, may not be completely distinctive. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.     

筛状-桑椹状型甲状腺乳头状癌1例报道及文献复习

目的 探讨筛状-桑椹状型甲状腺乳头状癌的病理特征。方法 复查1例女性患者的临床资料及病理切片行免疫组化标记,选用的一抗有CKpan、CK19、EMA、TG、TTF1、CD99、CT、SYN和CgA,并复习文献。结果 肿瘤位于甲状腺右叶。大体为淡白色卵圆形孤立实性肿块。组织学表现为乳头状、筛状、桑椹状、滤泡状、小梁状、肉瘤样、实性的结构伴囊性变和组织细胞反应,未见砂粒体。免疫组化显示肿瘤性的乳头状上皮、筛状和肉瘤梭形细胞表达CKpan和CK19。结论 甲状腺乳头状癌中的乳头状、筛状-桑椹状肿瘤细胞和肉瘤样的梭形细胞具有表达上皮性细胞的特征,该肿瘤是乳头状癌的一种罕见的变型。     

Cytologic findings of myxoid neurothekeoma: case report based on fine-needle aspiration cytology,immunohistochemistry, and correlating histopathology

Myxoid neurothekeomas (nerve sheath myxomas) are rare benign cutaneous neoplasms that may morphologically mimic other myxoid neoplasms of skin and soft tissue. The cytologic and histopathologic features of this lesion may resemble various myxoid sarcomas, chordoma, myxoid neurofibroma, dermal cutaneous mucinosis, and cutaneous myxoma as well as other myxoid or chondroid neoplasms. In this study, a myxoid neurothekeoma was analyzed using multiple techniques. We found that myxoid neurothekeomas reveal a nonspecific pattern by fine-needle aspiration, including stellate cells embedded within an abundant metachromatic myxoid stromal matrix. These are cytologic features shared by various other subcutaneous neoplasms and thus may not be helpful in forming a definitive diagnosis. Histopathologically, the tumor is composed of nodules of myxoid stroma containing interspersed bland spindled and stellate cells. Immunohistochemical studies show tumor cell positivity for S-100 protein and vimentin, a profile shared by other neoplasms with similar cytologic features and therefore of little diagnostic value. The histologic and cytologic differential of subcutaneous and soft tissue myxomatous lesions is broad and, therefore, is of unique value to the cytopathologist to consider myxoid neurothekeomas among the differential of other myxomatous neoplasms.     

Clear cell dermatofibroma: a case report with cytogenetic study

We report an observation concerning a 48-year-old male who presented with a 5 cm tumour on his left leg, first noticed 18 months ago. The remainder of clinical examination was normal. Histological assessment revealed a tumoral infiltration of entire dermis and superficial hypodermis. This tumour consisted of monomorphous, ovoid or spindle cells, with clear cytoplasm and PAS+ granulations. There was strong immunoreactivity by tumoral cells only for vimentin. Ultrastructural studies revealed fibrohistiocytic-like tumoral cells, without epithelial, muscular, vascular or melanocytic differentiation. These results were consistent with the diagnosis of clear cell dermatofibroma. Cytogenetic evaluation and FISH analysis showed a deletion of p12. Clear cell dermatofibroma is a rare and recent variant of dermatofibroma, with a difficult histological evaluation and which must be differentiated from clear-cell sarcoma. This observation is the first case-report of this entity, to our knowledge, showing a cytogenetic abnormality.     

骨外黏液样软骨肉瘤病理与鉴别诊断附4例报道并文献复习

目的 探讨骨外黏液样软骨肉瘤(extraskeletal myxoid chondrosarcoma,EMC)的临床病理特点、免疫表型及病理诊断与鉴别诊断要点.方法 收集4例EMC,对其临床、病理组织学及免疫表型进行观察并复习相关文献.结果 4例患者均为成年男性,平均年龄40.2岁,平均病程约30.3个月.主要表现为无痛性或有触痛性软组织肿块,3例发生于下肢,1例发生于胸壁.病理检查:(1)眼观见瘤体最大径平均6.5 cm,切面呈多结节状,有黏液感,界清.(2)镜检见肿瘤呈分叶状生长,瘤细胞排列呈索状、簇状或纤细网状.3例间质富于黏液样基质,1例富于软骨样基质,血管较稀疏.免疫组化:4例均表达Vim(4/4),3例表达S-100蛋白(3/4),2例表达NSE(2/4),2例表达CgA和Syn(2/4),1例表达CKpan(1/4),1例Ki-67阳性率为50%,3例Ki-67阳性率均<5%,4例均不表达SMA和EMA.结论 EMC是一种罕见的软组织肿瘤,其诊断主要依靠发生部位和组织病理学特征,免疫组化标记可帮助诊断和鉴别诊断.     

Myxoid change within cellular blue naevi: a diagnostic pitfall

We describe four cases of a distinctive myxoid change located in the centre of cellular blue naevi. Because all the reported lesions were large and were present on pressure-exposed locations, the myxoid change is thought to be caused by pressure together with direct repeated minor tissue trauma.     

骨外黏液样软骨肉瘤5例并文献复习

目的：探讨骨外黏液样软骨肉瘤( extraskeletal myxoid chondrosarcoma, EMC)的临床病理学特征、诊断和鉴别诊断。方法回顾性分析5例EMC的临床病理学特征并复习相关文献。结果5例患者中男性4例,女性1例,年龄32~62岁,中位年龄52岁。肿瘤位于大腿4例,左胸部1例。镜检：瘤细胞为圆形或卵圆形,形态及大小较为一致,细胞胞质嗜酸性,核小而深染,圆形或卵圆形,呈特征性的细网状、带状或假腺泡状排列,细胞之间为数量不等的黏液样物质。免疫表型：5例肿瘤细胞均强阳性表达vimentin,2例局灶表达S-100,1例表达Syn;不表达CK、p63、EMA、CD34、SMA等。 RT-PCR检测显示EMC染色体9号与22号易位。结论 EMC是一种较为罕见的疾病,临床及影像学无特征性,确诊主要依靠病理组织学检查、免疫表型及分子遗传学检测等方法;EMC是一类生长缓慢,但局部复发和转移率高的恶性肿瘤。     

伴假腺样结构的黏液型肾上腺皮质腺瘤6例临床病理特征分析

目的探讨伴假腺样结构的黏液型肾上腺皮质腺瘤(myxoid adrenocortical adenoma,MACA)的临床病理学特征及生物学行为。方法采用免疫组化法检测6例MACA中vimentin、Syn、α-inhibin和Melan-A等的表达,回顾性分析MACA的临床病理学特征及随访,并复习相关文献。结果 6例患者年龄31~64岁,男女比为1∶2。4例既往有高血压病史。肿块重15~150 g,最大径2~11 cm。MACA肿瘤间质显著黏液变性(30%~100%),瘤细胞黏附性差,呈假腺腔样结构排列,或呈梁索状、微囊状、簇状等形态。黏液型与经典型皮质腺瘤混合。MACA不同程度表达vimentin、Syn、α-inhibin和Melan-A。间质黏液样物质阿尔辛蓝染色阳性,PAS染色阴性。术后随访11~72个月,无复发及转移。结论 MACA临床罕见,肿瘤组织结构多样,需与其他肿瘤鉴别,完整切除肿瘤后应密切随访。     

Perineal lipoblastoma: a case report and review of literature

Lipoblastoma is a rare benign mesenchymal tumor that composes of embryonal white fat tissue and typically occurs in infants or young children under 3 years of age. It usually affects the extremities, trunk, head, and neck. The perineum is a rare location with only 7 cases reported in the literature. We describe a case of 3-year-old girl with a lipoblastoma arising from perineum. An approximately 4.5 cm × 3.5 cm × 2.5 cm nodule was resected in left perineum with satisfied results. Pathological examination showed that it was composed of small lobules of mature and immature fat cells, separated by fibrous septa containing small dilated blood vessels. The left perineal lipoblastoma, although rare, should be differentiated from some other mesenchymal tumors with similar histologic and cytological features.     

骨外黏液样软骨肉瘤2例报道及文献复习

目的探讨骨外黏液样软骨肉瘤的临床病理学特征。方法对2例骨外黏液样软骨肉瘤进行光镜观察及免疫组化染色标记,并通过相关文献复习,对病理诊断及鉴别诊断等指标进行分析。结果1例发生于足底,1例发生于乳腺。光镜下肿瘤呈分叶状,边界清。细胞为圆形及短梭形,成束状排列于黏液样基质中,局部可见围血管形成玫瑰花结样结构。部分肿瘤细胞异型性明显。免疫表型:vimentin、NSE、Syn均呈阳性;例1EMA灶性阳性,例2阴性;S-100蛋白、CgA及CK均阴性。结论骨外黏液样软骨肉瘤为罕见的软组织恶性肿瘤,具特异性的组织病理学特点。主要发生于四肢,少数可发生于实质器官,至今未有乳腺原发病例报道。部分肿瘤细胞可发生间变导致诊断困难,须与脊索瘤、骨内软骨肉瘤、化生性癌及黏液性肿瘤等鉴别。