Thymoma and thymic carcinoma arising in a thymolipoma: report of a unique case

Thymic carcinoma arising within a thymolipoma has not been reported previously. The authors present a unique case of thymoma and undifferentiated thymic carcinoma arising within a thymolipoma in a 36-year-old woman. The bulk of the resected mass was composed of benign fatty tissue admixed with foci of unremarkable thymic tissue; however, it also harbored a central solid mass showing undifferentiated thymic carcinoma associated with a type B2 thymoma. The carcinoma cells were positive for cytokeratin AE1/AE3, cytokeratin 19, and cytokeratin 8/18. They were negative for vimentin, cytokeratin 7, cytokeratin 20, CD5, epithelial membrane antigen, CD30, placental alkaline phosphatase, carcinoembryonic antigen, CD99, leukocyte common antigen, Epstein-Barr virus, inhibin alpha, and protein gene product 9.5. Rare tumor cells showed positive staining for chromogranin and synaptophysin.     

Tubular seminoma of the testis

A case of tubular seminoma in a 33-year-old man is reported. The tumor occurred in his right testis, measuring 7 x 6 x 6 cm in size. Microscopically, most of the tumor cells were arranged in solid or hollow tubular patterns. The tumor cells had round nuclei with vesicular chromatin and clear or granular cytoplasm, characteristic features of seminoma cells. A classic seminoma component and intratubular atypical germ cells occupying approximately 5% of the tumor area were noted. Immunohistochemical staining revealed that the tumor cells were diffusely placental alkaline phosphatase and vimentin positive, and focally cytokeratin positive. These findings are consistent with a tubular seminoma. The differential diagnoses are discussed.     

Yolk sac tumor of the stomach with an adenocarcinomatous component: A case report with immunohistochemical analysis

A 56-year-old male treated for a gastric yolk sac tumor with an adenocarcinomatous component is described. A mixed area of reticular and glandular neoplastic components was morphologically identified in this tumor. Immunohistochemically, the yolk sac tumor expressed alpha-fetoprotein (AFP), placental alkaline phosphatase (PLAP), and cytokeratin, but was negative for carcinoembryonic antigen (CEA). The adenocarcinoma was positive for CEA and cytokeratin, partially positive for PLAP, and negative for AFP. In the mixed area, the tumor cells were positive for cytokeratin, weakly expressed AFP and PLAP, and sporadically stained for CEA both in the reticular and glandular components. This area was identified as a transitional area of the yolk sac tumor and adenocarcinoma. These findings demonstrate that the yolk sac and adenocarcinomatous components are closely related. It also suggests that the tumor arose from multipotential neoplastic mucosal epithelial cells with both yolk sac and gastric mucosal phenotypes.     

Ovarian mixed germ cell tumor composed of dysgerminoma, endodermal sinus tumor, choriocarcinoma and mature teratoma in a 44-year-old woman: Case report and literature review

A case of ovarian mixed germ cell tumor In a 44-year-old woman was examined. The tumor was well circumscribed, measured 15 times 11 times 10cm and appeared solid and partly cystic on the cut surface. Light microscopic examinations revealed that the tumor was composed of four different neoplastic germ cell elements, Intermingled with each other. They are: (i) choriocarcinoma, immunohistochemically positive for human placental lactogen (hPL) and human chorionic gonadotropin (hCG); (ii) dysgerminoma, positive for placental alkaline phosphatase; (iii) endodermal sinus tumor positive for α-fetoproteln (AFP); and (lv) mature teratoma. Among these histological types, dysgermlnoma occupied more than 50% of the neoplasm. The patient was diagnosed as a stage la ovarian mixed germ cell tumor and was subsequently treated with chemotherapy. A second-look laparotomy after completion of chemotherapy revealed no residual tumors in the abdomen and the patient Is alive and well 15 months after operation. This Is the fourth reported case of ovarian mixed germ cell tumor arising In patients over 40 years old.     

Cystic schwannoma of the pancreas

Intrapancreatic schwannoma is a rare neoplasm. We report a case of a 46-year-old man with a cystic schwannoma in the head of the pancreas. This tumor, based on clinical manifestations and radiologic features, was initially suspected to be a cystic mucinous tumor of the pancreas or a pseudocyst. Histologically, the tumor was a typical schwannoma with cyst formation caused by degenerative changes. Immunostaining showed the tumor cells to be strongly and diffusely positive for S-100 protein, vimentin, and CD56, and negative for cytokeratin AE1/AE3, desmin, smooth muscle myosin specific, CD34, and CD117, which support the diagnosis of schwannoma. Cystic schwannoma is a rare neoplasm occurring in the pancreas and should be considered in the differential diagnoses for patients presenting with pancreatic cystic lesions.     

Small-cell mesothelioma of the pleura: description of a case

A case of mesothelioma with a small cell component in a 53-year-old, non-smoker woman. The patient had a history of asbestos exposure, and presented with thoracic pain. A total body computed tomogram showed a left pleural effusion and a 7.5-cm pleural mass. Thoracoscopy revealed a diffuse nodular thickening of the left parietal pleura, and a biopsy was performed. The patient died of the disease 4 months after diagnosis. Microscopically, the pleural neoplasm was composed of three different components: 40% of the tumor showed the classic histology of a malignant epithelial mesothelioma, 40% was composed of small- to medium-sized cells with open nuclear chromatin, evident nucleoli and high mitotic activity, and 20% of the neoplasm was indistinguishable from a small cell carcinoma. Immunohistochemically, the first component was diffusely and strongly positive for cytokeratin AE1/AE3, cytokeratin CAM 5.2 and EMA, focally positive for BER-EP4, and negative for CD15, B 72.3, CEA, LCA, chromogranin, synaptophysin, TTF-1 and CD99. The cells of the second component were positive only for cytokeratin AE1/AE3 and cytokeratin CAM 5.2, and the elements of the third component were negative for all the antibodies tested. Pleural mesothelioma with a small cell component is rare. The most useful parameters to distinguish it from other small cell malignancies that may involve the pleura, particularly small cell carcinoma of pulmonary origin, are discussed.     

Use of anti-seminoma monoclonal antibody to confirm the diagnosis of mediastinal seminoma. A case report

Chest x-ray in a 20-year-old man showed a large anterior mediastinal mass and a needle aspirate was diagnosed by light microscopy (LM) as non-Hodgkin's lymphoma. Treatment with CHOP (cyclophosphamide, adriamycin, vincristine and prednisone) was ineffective and a tissue biopsy was performed. LM showed large, non-cohesive cells with abundant cytoplasm and rounded nuclei. Differential diagnoses included malignant lymphoma, seminoma, thymoma, anaplastic carcinoma, malignant melanoma and paraganglioma. Electron microscopy was not conclusive and immunoperoxidase staining was carried out. The malignant cells were negative for common leukocyte antigen, Leu M1, alpha-fetoprotein, chorionic gonadotrophin, cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, S-100 protein and neuron-specific enolase but positive for placental alkaline phosphatase. In addition, there was strong positivity with a monoclonal antibody (mAb) which was recently shown to react with testicular seminomas. This case illustrates the value of this mAb in confirming the diagnosis of mediastinal seminoma.     

Sarcomatoid carcinoma of the small intestine: a case report and review of the literature

Sarcomatoid carcinoma of the small bowel is rare; to our knowledge, 19 cases have been reported to date in the English literature under several names. We report an additional case occurring in the jejunum of a 55-year-old man. The tumor was a polypoid 7.5-cm mass, which infiltrated the full thickness of the intestinal wall and the serosa of an adhesed loop of small bowel. On microscopic examination, the neoplasm was composed of sheets of spindle cells; focally, an anaplastic component was present, including tumor giant cells with bizarre nuclei. On immunohistochemical stains, tumor cells were positive for cytokeratin 7, cytokeratin AE1/AE3, vimentin, and focally, epithelial membrane antigen. No staining for cytokeratin 20 was found. Sarcomatoid carcinoma must be kept in mind in the differential diagnosis of malignant spindle cell tumors of the small bowel. As consensus regarding the terminology of these rare tumors is being reached, immunohistochemical stains are essential for accurate diagnosis.     

Ovarian Myxoma: Ultrastructural and Immunohistochemical Findings

The ultrastructural and immunohistochemical findings are reported in two ovarian myxomas, one of which was also associated with a sclerosing stromal tumor of the same ovary. Both neoplasms showed a myxoid, moderately cellular proliferation of spindle and stellate cells interspersed with areas of fibrosis and hemorrhage as well as delicate vascular spaces. Ultrastructurally, stellate neoplastic cells with irregular nuclei and occasional nucleoli were embedded in a mucinous and loose collagen matrix. Their cytoplasm showed abundant intracytoplasmic thin filaments that rarely condensed into poorly formed dense bodies. These thin filaments correlated with immunoreactivity for musclespecific actin and vimentin. The neoplastic cells showed no immunoreactivity with antibodies to desmin, S-100 protein, cytokeratin AE1 :AE3, factor Vlll-related protein, or placental alkaline phosphatase. These ultrastructural and immunohistochemical findings are consistent with myofibroblastic differentiation. These ancillary studies exclude important, clinically more aggressive differential considerations such as myxoid rhabdomyosarcoma, myxoid liposarcoma, myxoid neural tumors, mucinous adenocarcinoma showing pseudomyxomatous change, and myxoid-appearing endodermal sinus (yolk sac) tumor.     

Sclerosing Sertoli cell tumor without expression of typical sex cord stromal tumor markers: case report and literature review

Sertoli cell tumor is a potential histologic mimic of other tumors, such as seminoma due to similar histology and overlapping clinical presentation. Sclerosing Sertoli cell tumor is a rare sex cord stromal tumor variant, with 16 cases reported in the English literature. We present an unusual case of sclerosing Sertoli cell tumor in a 33-year-old Caucasian male, which was negative or weakly reactive using immunohistochemical markers typically positive in Sertoli cell tumors. The tumor was positive for cytokeratin AE1/AE3, CAM 5.2, vimentin, CD56, CK8, synaptophysin and S100, and negative for inhibin, calretinin, WT1, CD99, CD117, CK5/6, CK7, chromogranin A, placental alkaline phosphatase, neuron specific enolase, D2-40, smooth muscle actin, Melan-A, epithelial membrane antigen and carbonic anhydrase IX. This is the second reported case of a Sertoli cell tumor with reactivity limited to neuroendocrine markers and the first such case of the sclerosing variant. A literature review of sclerosing Sertoli cell tumor, including English and non-English literature, is described. Our case highlights that expected immunohistochemical markers may be negative, and awareness of antigenically unreactive tumors is needed to avoid confusion between Sertoli cell tumor and other entities.     

中枢神经系统非典型畸胎样/横纹肌样瘤临床病理及免疫表型特征

目的 探讨中枢神经系统非典型畸胎样／横纹肌样瘤的临床病理特征、诊断及鉴别诊断。方法 对2例非典型畸胎样／横纹肌样瘤应用光镜行HE、网状纤维染色及免疫组织化学染色观察,并结合文献复习。结果 非典型畸胎样／横纹肌样瘤具有特征性的横纹肌样细胞,伴有不同程度的原始神经外胚叶、上皮和间质分化。肿瘤组织富于网状纤维,免疫组织化学标记示波形蛋白、CD99、上皮细胞膜抗原、细胞角蛋白、胶质纤维酸性蛋白、S-100蛋白、神经微丝蛋白、结蛋白、平滑肌肌动蛋白阳性,突触素、肌调节蛋白、胎盘碱性磷酸酶和HMB45阴性。结论 非典型畸胎样／横纹肌样瘤是中枢神经系统一种罕见的高度恶性肿瘤,好发于儿童,偶见于成人,呈异源性组织学和免疫组织化学表型。其诊断需与脑内其他多形性肿瘤鉴别。     

Nasal myoepithelioma removed through endonasal endoscopic surgery: a case report

Myoepithelioma is a rare neoplasm that can occur in either the major or minor salivary gland and accounts for less than 1% of salivary gland neoplasms. We report a rare case of a nasal myoepithelioma that originated from the nasal inferior turbinate. The tumor, measuring 50 × 30 × 20 mm, was in the right nasal cavity and had a necrotic surface. We removed the tumor through endonasal endoscopic surgery. The tumor had spindle-shaped cells and was positive for cytokeratin, (AE1/AE3), vimentin, S-100β, and MIB-1 but was negative for CD34, desmin, neuron-specific enolase, and synaptophysin. Slight immunoreactivity for smooth muscle actin was noted in some tumor cells. There has been no evidence of tumor recurrence in the 18 months following surgery.     

Granular cell tumor (Abrikossoff tumor) of the thyroid gland

Only 4 cases of granular cell tumor of the thyroid have been previously reported in the English literature. We report herein the fifth case of this uncommon neoplasm and the first one affecting a male patient. The tumor was well circumscribed and located to the left thyroid lobe, near the isthmus. Histologically, the tumor was composed of large, rounded, granular eosinophilic cells that were immunohistochemically positive for S-100, calretinin, and PGP9.5 and negative for cytokeratin AE1-3, TTF-1, and thyroglobulin.     

纵隔芯针活检的病理诊断

目的 提高纵隔芯针穿刺组织的诊断准确性并做出具体分类。方法 用光镜、免疫组织化学抗生物素蛋白-生物素复合物法(ABC法)回顾性观察65例纵隔穿刺组织的形态和免疫组织化学表型,利用聚合酶链反应(PCR)检测部分非霍奇金淋巴瘤的基因重排状况,并随访。结果 本组标本镜下主要由不同比例的上皮样细胞、淋巴样细胞和纤维组织组成,包括21例淋巴瘤、20例肺癌、14例胸腺瘤、4例胸腺癌、3例精原细胞瘤、1例慢性炎症。2例因穿刺组织过少,无法诊断。本组淋巴瘤依不同类型可表达CD20、CD3、末端脱氧核苷酸转移酶(TDT)、CD30、D15或上皮膜抗原(EMA);除3例肺小细胞癌细胞角蛋白(CK)阴性外,17例肺癌均表达CK;10例肺和1例胸腺小细胞癌突触素、嗜铬粒素A(CgA)、神经元特异性烯醇化酶(NSE)均阳性,CD5阴性;3例肺腺癌甲状腺转录因子阳性,CD5阴性;14例胸腺瘤CK、CD3或CD20可阳性;3例胸腺癌表达CK和CD5;3例精原细胞瘤胎盘碱性磷酸酶阳性、CK阴性。5例淋巴母细胞性淋巴瘤T细胞型的T细胞受体B链的编码基因存在重排,3例大B细胞淋巴瘤和1例大细胞间变B细胞淋巴瘤存在免疫球蛋白重链编码基因的重排。结论 纵隔穿刺组织的镜下诊断需结合临床和影像资料,选择适当的免疫组织化学套餐,才能提高确诊率,并可对有疑问的非霍奇金淋巴瘤病例进行克隆性分析。     

Primary follicular lymphoma of the testis in childhood: an entity with peculiar clinical and molecular characteristics

BACKGROUND/AIMS: Paediatric primary follicular lymphoma of the testis (PPFLT) is exceptional: the few reported cases seem to lack BCL-2 gene rearrangement and/or protein expression. The aim of this study was to characterise a PPFLT arising in a 4 year old boy. METHODS: This case was characterised using conventional histological analysis, immunohistochemistry, and a polymerase chain reaction based method for the detection of immunoglobulin V(H) chain rearrangements. RESULTS: The neoplasm was staged I(E)/A; left orchiectomy and chemotherapy were performed, producing complete remission. Histology showed a predominantly follicular lymphoid infiltrate mainly composed of centroblast-like cells. The phenotype was CD20(+), CD79a(+), CD10(+), bcl-6(+), B cell specific activating protein(+), kappa light chain(+), CD30(-/+), interferon regulating factor 4(-/+), c-myc(-/+), lambda light chain(-), CD3(-), bcl-2(-), p53(-), cytokeratin(-), and placental alkaline phosphatase(-). Lymphomatous elements were found within a CD21(+) follicular dendritic cell network and 70% were positive for Ki-67/MIB-1. Molecular analysis revealed monoclonal immunoglobulin heavy chain gene rearrangement and BCL-6 mutations, in the absence of BCL-2 major breakpoint and BCL-2 minor cluster region rearrangements, p53 mutations, and death associated protein kinase gene hypermethylation. CONCLUSIONS: These findings suggest a different pathogenesis of PPTFL compared with adult follicular lymphoma and might explain its favourable course in spite of aggressive histology.     

Plasmablastic lymphoma may occur as a high-grade transformation from plasmacytoma

Plasmablastic lymphoma (PBL) is an uncommon aggressive lymphoma arising most frequently in the oral cavity of HIV-infected patients. Rare cases of PBL have been reported in extraoral sites, particularly extranodal sites, as well as in immunocompetent patients. We report an unusual case of PBL in a 69-year-old, HIV-negative non-immunocompromised man presenting with generalized lymphadenopathy. To our knowledge, this is the first case of PBL presented as primarily generalized lymphadenopathy in HIV-negative patients. Histologic examinations of cervical, inguinal and axillary lymph nodes demonstrated a neoplastic proliferation of large cells with extensive necrosis. The neoplastic cells formed sheets with a relatively cohesive growth pattern interspersed by small lymphocytes and plasma cells. The large tumor cells expressed MUM1, OCT-2 and BOB.1, and were negative for CD138, CD38, AE1/AE3, melan A, PLAP, S100, vimentin, CD117, CD30, ALK-1, leukocyte common antigen (CD45), T-cell, B-cell and histolytic markers, CD56, CD10 and BCL-6. The proliferation index by Ki-67 immunohistochemistry was approaching 100%. In situ hybridization for Epstein–Barr Virus-encoded RNA (EBER) was positive in large malignant cells. A diagnosis of PBL was made. These findings indicate that PBL should be included in the differential diagnosis of an HIV-negative, immunocompetent patient with generalized lymphadenopathy. The adjacent plasma cells were positive for CD138 and CD38 and show kappa-light chain restriction, but without EBER expression, raising the possibility of a preexisting or concurrent plasmacytoma and that the PBL may be a high-grade transformation from a preexisting plasma cell neoplasm following Epstein–Barr virus infection. Electron microscopy showed numerous circumferential long slender peripheral cytoplasmic projections in the large tumor cells, suggesting that some of the previously reported large B-cell lymphoma with cytoplasmic projections may actually be PBL.     

Sarcomatoid salivary duct carcinoma of the parotid gland

Salivary duct carcinoma (SDC) is a high-grade neoplasm known to histologically resemble high-grade ductal carcinoma in situ of the breast. We describe 3 cases of sarcomatoid salivary duct carcinoma, a heretofore unreported variant of SDC. Each case was a composite of SDC and sarcomatoid carcinoma and histologically similar to reported cases arising in the breast. The clinicopathologic features, including immunohistochemistry, of 3 cases were investigated. In the 3 men, ages 56, 68, and 70 years, the resected parotid tumors measured 1.5, 3.5, and 1.5 cm, respectively. Only the 3.5-cm tumor extended beyond the parotid gland into soft tissue. This patient died at 3 years with pulmonary metastases. The other patients were free of disease at 6 and 12 months. Histologically, each case was a composite of usual-type SDC and sarcomatoid carcinoma. SDC showed typical cribriform architecture, whereas anaplastic, spindled cells constituted the sarcomatoid areas. Immunohistochemically, epithelial elements stained as follows: cytokeratin (AE1/AE3 & CAM 5.2) positive in 3 of 3 cases, EMA positive in 3 of 3 cases, vimentin negative in 3 of 3 cases, desmin negative in 3 of 3 cases, c-erbB-2 positive in 1 of 2 cases. Sarcomatoid elements stained as follows: AE1/AE3 negative in 3 of 3 cases, CAM 5.2 rare positive cell in 1 of 3 cases, EMA focally positive in 3 of 3 cases, vimentin positive in 3 of 3 cases, desmin negative in 3 of 3 cases, c-erbB-2 negative in 2 of 2 cases. Electron microscopy, performed in one case, showed scattered junctional complexes congruent with epithelial differentiation. Immunohistochemical results, EMA and CAM 5.2 positivity, and ultrastructural findings supported our belief that these unique biphasic tumors represented SDC with sarcomatoid carcinoma. We conclude an element of sarcomatoid carcinoma rarely may arise in association with SDC, and it is erroneous to diagnose such tumors as "carcinosarcoma."     

Sarcomatoid carcinoma of the pancreas: A case report with immunohistochemical study

Sarcomatoid carcinoma of the pancreas is an uncommon neoplasm. The immunohistochemical characteristics of this unique type of pancreatic tumor were studied. Histologically, there was diffuse proliferation of atypical spindle cells that had hyperchromatic, short, spindle-shaped nuclei and pale cytoplasm. A few tiny foci of small tubular structures were seen in connection with the atypical spindle-shaped cells. Immunohistochemical examination showed that the spindle cells were positive for epithelial cell markers (cytokeratin AE3, cytokeratin AE1, epithelial membrane antigen) and DF3 (MUC1 apomucin-related antigen (ARA)), and were negative for markers such as vimentin, desmin, neuron-specific enolase, and myoglobin. DF3 antigen is known to be expressed in invasive ductal carcinoma of the pancreas and liver, as well as of the breast. Other MUC1-ARA (MY.1E12, MUC1 glycoprotein, HMFG-1, HMFG-2) and anti-CA19-9 were also detected in the present case. Thus, this tumor was diagnosed as anaplastic carcinoma (sarcomatoid carcinoma).     

Solitary Fibrous Tumor of the Adrenal Gland with Unusual Immunophenotype: A Potential Diagnostic Problem and a Brief Review of Endocrine Organ Solitary Fibrous Tumor

Solitary fibrous tumor was initially thought to be a pleura-based tumor. However, over the last two decades, its involvement in a variety of extrapleural sites gained recognition. Nonetheless, a primary involvement of the endocrine organs is rare, and in this report, we detail an instance where the tumor affected the adrenal gland of a 71-year-old Arab man. On histology, besides the typical morphologic features seen in solitary fibrous tumor, the neoplasm also exhibited unusual features on immunohistochemistry such as positive staining for cytokeratin AE1/3 and calponin in conjunction with diffuse expression for S-100. The genetic tests for t(X:18) as seen in synovial sarcoma were negative, and the overall histological appearance favored a diagnosis of solitary fibrous tumor. To the best of our knowledge, this report represents the fifth case of a solitary fibrous tumor primarily occurring in the adrenal gland. The differential diagnoses of this neoplasm in our case and a brief summary of solitary fibrous tumor primarily involving the various endocrine organs are presented.     

Plasmablastic lymphoma affecting the lung and bone marrow with CD10 expression and t(8;14)(q24;q32) translocation

Plasmablastic lymphoma is a rare variant of a diffuse, large B-cell lymphoma, which typically presents in the oral cavity in immunocompromised patients. In HIV positive patients, this tumor has a tendency to manifest in extramedullary sites. In this report, we document a rare instance in which this neoplasm besides affecting the bone marrow also involved the lung. In addition, the lymphoma in our case disclosed CD10 positivity on immunohistochemistry and t(8;14)(q24;q34) translocation on cytogenetic analysis, mimicking a Burkitt/atypical Burkitt lymphoma. The problems in diagnosis are discussed.