Solitary fibrous tumor of the vagina

The solitary fibrous tumor (SFT) is a rare tumor that most commonly arises in the pleura. Recent evidence has indicated that this tumor originates from mesenchymal, probably fibroblastic, cells and is not restricted to the pleura. However, its occurrence in the female genital tract is extremely rare. We report a case of primary SFT that originated from the vagina in a 34-year-old female. It was a pedunculated polypoid tumor and occurred at the site of scar tissue, caused by laceration during her last labor 7 years previously. Histologically, the tumor was predominantly composed of a random proliferation of spindle cells, intimately admixed with collagen. Immunohistochemically, the cells were strongly positive for CD34, vimentin and bcl-2, but were negative for S-100 protein, neuron-specific enolase, smooth muscle actin, desmin, CD68, cytokeratins and epithelial membrane antigen. To the best of our knowledge, this is the first reported case of a primary vaginal SFT in the English literature. Our report suggests to include SFT in the differential diagnosis of a spindle cell neoplasm originating from the vagina.     

Solitary fibrous tumor of the prostate: a report of two cases

We here report two cases of solitary fibrous tumor (SFT) arising in the prostate. Two men, 66 and 69 years old, with urinary tract symptoms were diagnosed with SFT on transrectal needle biopsy and transurethral resection of the prostate, respectively. The tumors were removed by a low anterior resection including tumor, prostate and rectum en bloc and cystoprostatectomy, respectively. Both tumors were well-circumscribed but also showed some infiltration of the prostate glands. They were composed of storiform bundles of bland spindle cells that stained strongly for CD34 and vimentin but negative for muscle markers. Although rare, SFT should be considered as differential diagnosis of spindle cell lesions on prostate biopsies.     

Solitary fibrous tumor of the prostate

A case of solitary fibrous tumor of the prostate Is reported. A 42-year-old man had been complaining of difflcult volding and constlpation for 8 years. Urological and radiological examinations showed a large prostatic mass, and a total cystectomy and prostatectomy were petformed. The tumor was 14×13×11 cm in size, solid with a fibromuscular capsule, and graytan in color. Histological, the tumor was composed of short spindle-shaped and polygonal cells with mild to moderate nuclear atypla, predominantly arranged in the so-called 'patternless pattern' in a flbrocoliagenous background. Mitoses were occasionally seen. Vascular invasion was also observed. Immunohistochemically, these cells were strongly positive for CD34 and vimentin, and occasionally for desmin. The maximum K1–67 labeling Index of the tumor cells was 4.5%. These findings are consistent with a solitary fibrous tumor. To our knowledge, this is the first report of a solitary fibrous tumor of the prostate in the English medical literature.     

Comparison of sporadic sclerotic fibroma and solitary fibrous tumor in the oral cavity

Sporadic sclerotic fibroma (SF) and solitary fibrous tumor (SFT) arising in the oral cavity are very rare. In this report, we describe two cases of oral pathology, one involving SF and the other involving SFT. Both cases presented with well- circumscribed, firm nodules with similar gross findings. However, the histologic findings of the SF and SFT showed rather distinct features. The SF was composed of hyalinized sclerotic collagen bundles arranged in a whorled pattern, whereas the SFT was formed by spindles cells arranged in hypo- and hypercellular areas. The immunohistochemical findings were similar in both cases; there was positivity for vimentin, CD34, and CD99, but bcl-2 positivity was only seen in the SFT. Although their histopathologies are similar, SF and SFT should be considered in the differential diagnosis of soft tissue tumors in the oral cavity.     

Solitary fibrous tumor arising in gastric serosa

The solitary fibrous tumor (SFT) of peritoneum, especially arising in gastric serosa, is extremely rare. A case of SFT arising in gastric serosa of a 70-year-old man is reported. On abdominal computed tomography scan, an approximate 8.0 × 5.3 cm-sized solid mass with multiple nodular calcifications was noted in the omentomesentery of right upper abdomen, which was abutting to the gastric antral wall. At laparotomy the tumor was tightly attached to the gastric serosa and was completely excised by wedge resection of the stomach. The cut surfaces of the tumor were pale brown to pale yellow, firm, with multifocal yellowish, gritty, stony-hard nodules and cystic changes. Microscopically, the tumor was composed of mildly cellular benign-appearing spindle-shaped cells and bands of hyalinized collagen in varying proportions. The tumor revealed predominantly sclerosing pattern with extensive hyalinized fibrosis and multifocal dystrophic calcifications. The tumor was mainly located at the gastric serosa and subserosa, and its growth pattern was expansile with entrapping of muscularis propria and submucosa in the periphery of the tumor. By immunohistochemistry, the tumor cells were diffusely positive for CD34 and vimentin but negative for cytokeratin, desmin, smooth muscle actin, CD99 and c-kit. Although its occurrence is rare, SFT should be considered in the differential diagnosis of mesenchymal tumors of the stomach.     

Solitary fibrous tumor of the lung: a case report with a study of the aspiration biopsy, histopathology, immunohistochemistry, and autopsy findings

Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm of ubiquitous location. In addition to its classic presentation as a pleural-based mass, it can be encountered in a variety of other sites. A pleural-based lung lesion can be easily accessed by radiologic guidance for cytologic study. Several reports have described the cytologic findings of SFT at various locations, including the lung. However, diagnostic difficulties can occur due to unusual clinical, radiologic, atypical cytomorphologic, and histologic features. We describe a case of intrapulmonary SFT in which a false-positive malignant diagnosis was rendered on fine-needle aspiration biopsy and concurrent surgical core biopsy prior to radiofrequency ablation. The patient died of procedural complications, and an autopsy was performed. Retrospective study of the case, especially correlation of cytologic, histologic, autopsy findings, and immunohistochemistry results were helpful in correctly diagnosing the case as SFT. We are reporting this case with emphasis on avoiding diagnostic pitfalls by being familiar with the accepted cytohistologic features and appropriate immunohistochemical results.     

Solitary fibrous tumor of the thymus with variegated epithelial components

Solitary fibrous tumor is a rare mesenchymal neoplasm, characterized by peculiar histological features composed by the proliferation of spindle cells in “patternless pattern”. Although it has been known to sometimes be accompanied by epithelioid cells, the presence of a well-formed epithelial structure is far more rare. We describe herein the case of a 60-year-old female with the radiological finding of a single nodular lesion in the anterior mediastinum. Histopathological examination of the surgically resected specimen led to the diagnosis of solitary fibrous tumor of the thymus with a spectrum of well-formed epithelial components: i) glandular structure, reminiscent of breast or eccrine gland, ii) neural tube-like structure, and iii) clusters of endocrine-like cells. Immunohistochemical analysis revealed that the spindle cells expressed CD34, vimentin, bcl-2 and Stat-6, but not keratin (cytokeratin-AE1/AE3) or epithelial membrane antigen. In contrast, the epithelial components lost expression of most of these marker proteins, including Stat-6, but continued to express vimentin and strongly expressed keratin. Since no relevant past literature was found, the current case could be interpreted as a unique and previously undescribed variant of solitary fibrous tumor comprising conventional spindle cells with a spectrum of well-formed epithelial components. Pathogenesis that may have given rise to these variegated mixtures of spindle cells and epithelial components in a single tumor is also discussed.     

外阴孤立性纤维性肿瘤1例临床病理观察及文献复习

目的 探讨外阴孤立性纤维性肿瘤的临床病理学特点、免疫组化特征及鉴别诊断.方法 对1例外阴孤立性纤维性肿瘤进行组织学观察,行EnVision两步法免疫组化CD34、bcl-2、CD99、vimentin、CKpan、HMB-45、α-SMA、CD117、S-100蛋白、ER、PR、Ki-67染色及随访,并复习相关文献.结果 患者女,62岁.发现右侧外阴肿物4年余.眼观:肿瘤呈结节状,大小6 cm×5 cm×3 cm,切面灰白、实性,质韧.镜检:肿瘤由交替性分布的富于细胞和稀疏细胞区组成,梭形细胞呈束状、旋涡状或不规则状排列,部分与胶原纤维混杂,部分呈血管外皮瘤样结构.上皮样细胞有的围绕血管周围.细胞间细条索状、粗绳索样或疤痕样胶原纤维不规则性或石棉样的胶原物质沉积.瘤细胞CD34、bcl-2、CD99、vimentin均为阳性,CKpan、HMB-45、α-SMA、CD117、S-100蛋白、ER、PR均为阴性,Ki-67增殖指数<1%.结论 外阴孤立性纤维性肿瘤罕见,应与该部位相似形态的病变和血管外皮瘤样的肿瘤相鉴别.     

Clinicopathological features of solitary fibrous tumor of the meninges: An immunohistochemical reappraisal of cases previously diagnosed to be fibrous meningioma or hemangiopericytoma

Cases of solitary fibrous tumor (SFT) of the meninges are increasingly being reported. However, the real incidence of SFT among meningeal tumors has yet to be determined. We therefore clinicopathologically re-examined 64 meningeal tumors originally diagnosed to be either fibrous meningioma (FM group, n = 46) or hemangiopericytoma (HPC group, n = 18) while paying special attention to SFT. We thus reclassified one case from the FM group (2%) and one case from the HPC group (6%) to be SFT, both of which showed diffuse CD34-immunoreactivity and dense intercellular reticulin fibers but neither epithelial membrane antigen nor S-100 protein expression. The MIB-1 staining index of these cases were 6. 2% and 3.9%, respectively. The former recurred 15 years after the initial surgery and the patient underwent a second removal of the tumor. The patient has been alive with no evidence of recurrence for 7 years after the second surgery. The latter patient has been alive with no evidence of recurrence for 3 years postoperatively. The results confirmed that the incidence of SFT among meningeal tumors is relatively low, however, because of its clinically indolent nature, a careful histochemical examination is necessary to differentiate SFT from other neoplasms with a more aggressive nature. Our findings emphasize the need to clinically recognize this lesion as a distinct entity.     

Solitary fibrous tumor: a study of cytologic features of six cases diagnosed by fine-needle aspiration

Solitary fibrous tumor (SFT) is a spindle-cell neoplasm most often presenting as a pleural-based tumor but increasingly recognized in other locations. Few reports have described the cytologic features of SFTs. Six cases of SFT diagnosed by fine-needle aspiration (3 pleura, 2 retroperitoneum, and 1 orbit) were identified in the Mayo Clinic files. The smears (Papanicolaou-stained) and corresponding histologic specimens were reviewed. Immunohistochemical staining for CD34 was performed in all cases. The cytologic findings were similar in all cases. The tumor cells were oval to polygonal, with cellularity ranging from scant to moderate. The background contained irregular ropy fragments of collagen and a few inflammatory cells. Most cells were dispersed singly, but all cases contained irregular, loose aggregates of cells enmeshed in a collagenous matrix. The nuclei were uniformly bland, with evenly distributed, finely granular chromatin. All cases were immunoreactive for CD34. SFT has distinctive cytologic features that allow diagnosis in cytologic specimens with the help of appropriate immunocytochemical stains on accompanying tissue biopsy specimens. Distinctive cytologic findings predictive of clinical behavior were not identified.     

Solitary fibrous tumor of the thyroid: cytopathologic findings and differential diagnosis

Solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm that arises primarily from the pleura. Extrapleural occurrences are rare. To our knowledge, there is no published account of this entity in the thyroid in the cytopathology literature. We report the case of a 61-yr-old man who was evaluated at The Johns Hopkins Hospital for a slow-growing thyroid mass that was present for 2 yr despite thyroid hormone suppression. Thyroid-stimulating hormone (TSH) was within normal limits. The patient underwent ultrasound-guided fine-needle aspiration (FNA), which showed predominantly discohesive slender spindle-shaped cells and fragments of collagenized stromal tissue. After the FNA diagnosis of "thyroid neoplasm" was made, the patient underwent a near-total thyroidectomy, which revealed a SFT. Differential diagnosis of spindle cell lesions in thyroid is also presented.     

Solitary fibrous tumor of the pancreas

A 67-year-old woman was found to have an incidental pancreatic mass on computed tomographic examination of her abdomen in the course of investigation of hematuria. The radiologic features were of a hypervascular mass in the uncinate process of the head of the pancreas, and a preoperative diagnosis of a neuroendocrine tumor was favored. A Whipple procedure was performed. The uncinate process contained a 2.6-cm well-circumscribed mass. Histologic evaluation showed a lesion composed of alternating hypercellular areas made up of spindle-shaped cells and hypocellular areas with hyalinized, keloidal-like fibrous tissue. Occasional dilated vascular channels and entrapped pancreatic tissue were present within the lesion. Immunohistochemistry showed the lesion to be CD34, CD99, and bcl-2 positive. No evidence of atypia was noted, and the overall impression was of a benign solitary fibrous tumor of the pancreas. This is an unusual primary spindle cell neoplasm of the pancreas and should be considered in the differential diagnosis of all spindle cell lesions that occur in the pancreas.     

Solitary fibrous tumor with malignant potential arising in sublingual gland

A rare case is described of a solitary fibrous tumor (SFT) with malignant potential arising in the sublingual gland. A 59-year-old man presented with a 4-month history of a slowly enlarging painless mass in the center of the floor of the mouth. The tumor was a well-demarcated, firm mass with a multicystic lesion. The tumor exhibited highly cellular areas of spindle cells with patternless architecture alternating with hypocellular areas. The tumor cells were positive for CD34 and bcl-2 as well as vimentin, and negative for epithelial, myogenic, neurogenic and histiocytic markers. The tumor cells formed multiple satellite nodules around dilated ducts in the multicystic lesion, indicating infiltrative growth. In addition, areas exhibiting higher cellularity with increased mitoses were noticed in the satellite nodules, although cellular atypia was not obvious. These findings led to a final diagnosis of SFT with malignant potential. There has been no recurrence or metastasis for 27 months after the surgery. Solitary fibrous tumor of the salivary gland must be differentiated from various spindle cell neoplasms including myogenic, peripheral nerve sheath, fibroblastic and fibro-histiocytic spindle cell neoplasms, hemangiopericytoma and myoepithelioma. In addition to characteristic morphological features, an immunohistochemical positivity for CD34 and bcl-2 may aid in the diagnosis of SFT.     

Solitary fibrous tumor of the oral cavity with a predominant leiomyomatous-like pattern: A potential diagnostic pitfall

The diagnosis of solitary fibrous tumor (SFT) is usually straightforward if the typical morphologic features, including a wide variety of growth patterns, are identified. We report the clinical, radiologic, and pathologic findings of a rare case of intraoral SFT which exhibited a predominant leiomyomatous-like appearance, closely reminiscent of a leiomyoma, at both incisional and excisional biopsy. Histologically, the tumor was composed predominantly of intersecting fascicles of eosinophilic spindle-shaped cells, variably set in a fibrous stroma. A focal hemangiopericytoma-like growth pattern with alternating hypercellular and hypocellular areas, as well as the deposition of dense keloid-type collagen, raising the suspicion of SFT, could be identified only after a careful examination of the whole tumor. Immunohistochemistry was helpful in confirming the diagnosis of SFT, revealing a diffuse staining of neoplastic cells for vimentin, CD34, bcl-2 protein, and, focally, CD99. Myogenic markers (α-smooth muscle actin, desmin, h-caldesmon) were not expressed.     

肾恶性孤立性纤维性肿瘤1例报道及文献复习

目的 探讨肾脏恶性孤立性纤维性肿瘤的临床病理特征、鉴别诊断及治疗和预后.方法 报道1例肾恶性孤立性纤维性肿瘤的临床病理资料并复习文献.结果 患者男性,56岁.临床主要表现为乏力、出汗、心慌、气短1年,以低血糖原因待查入院.CT示左肾上方及左肾前下方见3个类圆形软组织密度影,与肾分界不清,大小分别为9 cm×8 cm×7 cm、7 cm×7cm×7 cm和4 cm×4 cm ×4 cm.增强后边缘轻度强化,中心不均匀强化.临床、CT检查考虑为左.肾癌.行左肾癌根治术.眼观:左肾上、下极分别见一肿块,切面灰白色,部分区见有坏死,与肾界限不清.镜检:肿瘤由短梭形或卵圆形细胞组成,排列成束状、旋涡状或不规则状.部分区域血管丰富,细胞密集呈血管外皮瘤样结构;部分区域细胞稀疏伴纤维化、黏液变性.肿瘤超过60%的区域内(尤其是肾下极肿块)瘤细胞丰富密集,有异型性,核分裂象多见(>4个/10 HPF),边缘呈浸润性生长,部分区可见出血坏死.免疫表型:肿瘤细胞vimentin、CD34弥漫阳性,CD99、bcl-2阳性,Ki-67增殖指数>20%.病理诊断:左肾恶性孤立性纤维性肿瘤(低度恶性).术后随访24个月情况良好.结论 肾恶性孤立性纤维性肿瘤非常罕见,确诊主要依靠病理形态学及免疫组织化学标记,并应与肾的其他梭形细胞肿瘤进行鉴别.治疗以手术完全切除为主,并注意长期随访.     

Solitary fibrous tumor of the spinal nerve rootlet: Case report and literature survey

Solitary fibrous tumor (SFT) is a rare tumor that arises most commonly in the pleura. Recent evidence indicated that it is a tumor that originates from mesenchymal, probably fibroblastic, cells and is not restricted to the pleura. This report presents a case of primary SFT occurring as a dumbbell-shaped tumor of the cervical spine (C4/5) in a 46-year-old Japanese female, probably originating from the spinal rootlet. The tumor was predominantly extradural, loosely attached to the dura mater, with a small intradural extramedullary part attached to the C5 anterior and posterior rootlets. Histologically, the tumor was predominantly composed of a haphazard proliferation of spindle cells separated by abundant collagen. Immunohistochemically, the cells were strongly positive for CD34, bcl-2 and vimentin, but were negative for S-100 protein, neuron specific enolase, cytokeratin and epithelial membrane antigen. The present case and review of the literature strongly suggest that SFT is an entity that should be considered in the differential diagnosis of tumors of the cerebrospinal region.     

Disseminated malignant solitary fibrous tumor of the pleura

Solitary fibrous tumor (SFT) of the pleura typically forms a localized pleura-based mass, and most are benign. A rare case of disseminated malignant SFT of the pleura is reported. The patient was a 71-year-old man who presented with complaints of shortness of breath to his primary care physician. A diagnosis of malignant mesothelioma was suspected, based on clinical, radiological and needle biopsy findings. He was referred to our institution for surgery. An extrapleural pneumonectomy, encompassing all pleural masses, was performed. Gross examination of the resected specimen was remarkable for numerous masses, ranging in size from 0.2 to 13.5 cm, covering the majority of the visceral pleura. Histologically, the tumor was composed of short spindle cells admixed with variable proportions of collagenous stroma. There were great intra- and intertumoral heterogeneity in tumor growth pattern, cellularity, pleomorphism and mitoses. Histologically malignant areas were present in all of the masses examined. The neoplastic cells were diffusely and intensely positive for bcl-2. Most tumor cells were also strongly stained for CD34 and CD99. Staining for cytokeratin was negative. The tumor also revealed p53 over-expression. Thus, the histological and immunohistochemical features of the tumor were consistent with a disseminated malignant SFT. This report shows that SFT rarely presents with disseminated pleural involvement, and a panel with CD34, bcl-2 and cytokeratin are valuable for differentiating SFT from malignant mesothelioma and other malignant spindle cell neoplasms of the pleura.     

孤立性纤维性肿瘤临床病理学观察

目的探讨孤立性纤维性肿瘤(solitary fibrous tumor,SFT)的临床、病理组织学、免疫组化特征,提高对该病的认识。方法对7例SFT病例进行大体观察、病理组织学及免疫组化En V ision二步法标记,观察V im、CD34、CD99、bc l-2 Des、SMA、HMBE-1、CK、S-100蛋白在SFT组织中的表达。结果7例SFT分别发生于胸腔、腹腔、纵隔、眼眶及胸壁软组织,临床表现为肿块压迫所致的症状,肿块1.5 cm×1.5 cm×1 cm~20 cm×20 cm×18 cm,光镜下肿瘤细胞由长梭形细胞构成束状、编织状排列,间质内有多少不一的胶原纤维,无特殊的组织构型及形态的多样性为其组织学特点。免疫表型:CD34、V im、CD99均为弥漫强阳性,bc l-2 5例阳性,Des、SMA、HMBE-1、CK、S-100蛋白阴性。结论SFT是一组形态多样、无特殊组织构型及有多少不一胶原纤维的梭形细胞肿瘤,其特殊的免疫表型,有助于对该病的诊断,但SFT的确诊必须结合组织形态和免疫组化共同完成。SFT的生物学行为取决于其组织学形态和肿块的大小及生长方式,完全切除肿块者预后较好。