1/53. Spindle epithelial tumor with thymus-like differentiation (SETTLE) of the thyroid with prominent mitotic activity and focal necrosis.Spindle epithelial tumor with thymus-like differentiation (SETTLE) is a rare, apparently low-grade spindle cell tumor of the thyroid gland occurring in young individuals and thought to be derived from thymic or branchial pouch remnants. Spindle epithelial tumor with thymus-like differentiation has little to no mitotic activity, and focal necrosis has been reported in one case. We present a case of SETTLE in a 29-year-old man that was initially evaluated by fine-needle aspirate biopsy and ultimately found to be consistent histologically with SETTLE. In this case, there were numerous mitotic figures among the spindle cells and focal necrosis. Spindle epithelial tumor with thymus-like differentiation has been considered to be a tumor of low malignant potential with metastases developing some years after diagnosis. This is the first case in which prominent mitotic activity and necrosis is reported perhaps representing an aggressive variant.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
2/53. Ectopic hamartomatous thymoma: a case study and review of the literature.Ectopic hamartomatous thymoma is a rare and distinctive tumor found in the deep soft tissues of the neck, which is characterized histopathologically by a mixture of spindle, epithelial, and adipose cell elements. We present a case of this lesion occurring in a 39-year-old male. The characteristic histochemical and immunohistochemical findings of these tumors are demonstrated. In addition, review of the reported histological, immunohistochemical and ultrastructural findings is presented together with a table of clinical findings in the tumors so far described. A brief discussion of theories of histogenesis and possible differential diagnosis is included.- - - - - - - - - - ranking = 0.17906834273477keywords = spindle (Clic here for more details about this article) |
3/53. Two cases of ectopic hamartomatous thymoma.Ectopic hamartomatous thymoma (EHT) is a rare benign neoplasm. Since it was named by Rosai et al. in 1984, 24 cases have been reported. We herein report two cases of EHT, one of which presented with massive myoid cells, and review the literature related to EHT. Both of our cases displayed the typical features of EHT: (1) nests of epithelial cells, including solid, cystic, or glandular epithelial islands; (2) spindle cells dominating the microscopic picture; and (3) adipose cells which intermingle haphazardly to impart a hamartomatous quality to the tumor. In this paper, we observed massive myoid cells and the transition from spindle epithelial cell to myoid cell in one of our cases. Immunohistochemical examinations showed that the main component of EHT, spindle cells, was positive for cytokeratin and epithelial membrane antigen (EMA). Intriguingly, the myoid cells simultaneously expressed cytokeratin, EMA, myoglobin, and creatine kinase-mm, suggesting that myoid cells may originate from epithelial cells and are an intermediate state between epithelial cells and muscular cells.- - - - - - - - - - ranking = 1.1790683427348keywords = spindle cell, spindle (Clic here for more details about this article) |
4/53. Thymic carcinosarcoma consisting of squamous cell carcinomatous and embryonal rhabdomyosarcomatous components. Report of a case and review of the literature.A case of thymic carcinosarcoma in an 83-year-old Japanese man is presented. He died of superior vena cava syndrome caused by a rapidly enlarged anterior mediastinum tumor eight months after initial symptoms. autopsy revealed a 16 x 12 x 25 cm-sized, tan yellow, whitish tumor with a multinodular and microcystic appearance located in the left anterior mediastinum, which involved the residual thymus. The tumor had directly invaded the left pleura, and had metastasized to the right lung and spleen. Histologic examinations of the primary tumor showed a sarcomatous component consisting of racquet- or spindle-shaped cells with cross striations, and small nests of atypical squamous cells scattered throughout the tumor; neither transition between the two components nor intermediate cells with both epithelial and mesenchymal features was seen. Electron microscopic and immunohistochemical examinations confirmed the rhabdomyomatous differentiation of the sarcomatoid component. To our knowledge, there have been only two reported cases showing histologic features similar to the present tumor. For the histogenesis of thymic carcinosarcoma, we propose two hypotheses. The first is that sarcomatous cells are derived from carcinomatous cells by tumoral metaplasia. Secondly, that this type of tumor originates from thymic primitive cells with multidirectional differentiation potential. In accordance with the latter, we consider that the present tumor originated from thymic primitive cells. Thymic carcinosarcoma is a highly malignant tumor, and most patients die within a year. Appropriate therapies must be developed.- - - - - - - - - - ranking = 0.17906834273477keywords = spindle (Clic here for more details about this article) |
5/53. Histologic types of thymoma associated with pure red cell aplasia: a study of five cases including a composite tumor of organoid thymoma associated with an unusual lipofibroadenoma.The histologic type of thymomas associated with pure red cell aplasia (PRCA) has generally been regarded to be predominantly the spindle cell type. The 5 thymomas associated with PRCA we studied showed various histologic types and none of them was a spindle cell thymoma. Some cases reported as spindle cell thymoma associated with PRCA in the literature might not be spindle cell type. The discrepancy could be due to the lack of consensus in the histologic classification of thymomas in the past. Our study showed that thymomas associated with PRCA lacked a strong correlation with a particular histologic type and the pathogenesis of PRCA associated with thymoma did not seem to be related to the histologic type. One of our cases was an unusual composite tumor of an organoid thymoma (WHO type B1) and a hitherto undescribed "lipofibroadenoma." The clinical outcome was influenced by the invasive character and the histologic type of the thymoma.- - - - - - - - - - ranking = 2keywords = spindle cell, spindle (Clic here for more details about this article) |
6/53. thymoma with pseudosarcomatous stroma.thymoma with psuedosarcomatous stroma is a recently described, rare variant of thymomas that are characterized by having a biphasic histologic pattern which consists of both an epithelial and a spindle cell stromal component. So far only 11 cases having similar histologic findings have been reported worldwide. At this time we report a case of this rare variant of thymoma which occurred in a 53-year-old Korean man. This previously healthy patient presented with coughing and an anterior mediastinal mass was then detected radiographically. Mediastinal exploration revealed a 9 x 8 x 8 cm-sized well- encapsulated, ovoid, cystic mass. Histological examination showed a biphasic neoplasm composed of anastomosing nests of epithelial cells and somewhat cellular stromal spindle cells that had advanced degenerative changes. Immunohistochemical staining using the antibodies for cytokeratins, EMA, e-cadherin, and p75NGFR showed a strong expression of these markers in the epithelial component but no expression in the spindle stromal cells. The epithelial tumor cells showed no reactivity to CD5 and L26 and a high proportion of the infiltrated lymphocytes were the cortical type that expressed CD99 and terminal deoxynucleotidyl transferase. Ultrastructural examinations revealed tonofilaments in the spindle cells. Follow up has been done for 5 years after the surgical excision and the patient has been free of disease during that period. Similar to previous reports, this patient had a benign clinical course that was unassociated with myasthenia gravis which appears to be a characteristic of this histologic variant of thymoma. However, our case also showed advanced degenerative features and we could demonstrate ultrastructural evidence of epithelial differentiation in the stromal spindle cells that were not mentioned in the previously reported cases. Based on the results of our studies, we suggest this entity is a distinct type of organotypic thymoma that shows cortical differentiation and abundant cellular stroma.- - - - - - - - - - ranking = 2.1790683427348keywords = spindle cell, spindle (Clic here for more details about this article) |
7/53. Thymic sarcomatoid carcinoma with skeletal muscle differentiation: report of two cases, one with cytogenetic analysis.AIMS: Malignant thymic tumour histologically resembling a soft tissue sarcoma is extremely rare and defined as sarcomatoid carcinoma in the recent world health organization (WHO) classification. We report two such cases in which the tumour cells showed a prominent rhabdomyoblastic differentiation and analyse whether these tumours retain an epithelial nature at least in part. methods AND RESULTS: One tumour occurred in a 51-year-old man (Case 1) and the other in a 40-year-old woman (Case 2). Microscopically, both tumours consisted essentially of two types of tumour cells: spindle and large round cells, with no apparent epithelial components. Osteosarcomatous small foci were also found in Case 2. Immunohistochemically, desmin and muscle-specific actin were positive in the majority of both types of tumour cells, whereas myogenin was predominant in the spindle cells and myoglobin in the large round cells. Some of both types of cells expressed cytokeratin with co-expression of myoglobin in the large round cells, but with no myogenin in the spindle cells. Some cytokeratin-positive spindle cells were also negative for desmin. Ultrastructural examination of a recurrent tumour in Case 2 revealed some epithelial features among the spindle cells. Cytogenetic study of the same tumour showed a complex abnormality including der(16)t(1;16)(q12;q12.1), an identical pattern previously reported in a case of thymic squamous cell carcinoma. CONCLUSIONS: The findings support the definition in the WHO classification of sarcomatoid carcinoma that includes purely sarcomatous tumour as in the present cases. Occurrence of this type of tumour may indicate a relationship between thymic epithelial cells and myoid cells and/or a potential for divergent differentiation in thymic epithelial tumours.- - - - - - - - - - ranking = 2.1790683427348keywords = spindle cell, spindle (Clic here for more details about this article) |
8/53. Pigmented spindle cell carcinoid tumour of the thymus with ectopic adrenocorticotropic hormone secretion: report of a rare variant and differential diagnosis of mediastinal spindle cell neoplasms.AIMS: A variety of histological variants of thymic carcinoid tumour have been described. A rare case of pigmented spindle cell carcinoid tumour of the thymus is documented and compared with the reported cases of thymic pigmented carcinoid tumour in the literature, with a discussion of the differential diagnosis of spindle cell tumours of the mediastinum. methods AND RESULTS: A thymic tumour with ectopic adrenocorticotropic hormone (ACTH) secretion was resected from a 24-year-old man suffering from Cushing's syndrome. Histological, immunohistochemical, and ultrastructural studies revealed an ACTH-producing spindle cell carcinoid tumour harbouring pigmented melanocytes. Among four thymic pigmented carcinoid tumours reported before, only one was similar to the present case by being also an ACTH-secreting pigmented spindle cell thymic carcinoid tumour. The clinicopathological features of this tumour distinguish it from a spindle cell thymoma, spindle cell thymic carcinoma, and other mediastinal spindle cell tumours. CONCLUSIONS: This case illustrates an extremely rare variant of thymic carcinoid tumour exhibiting a spindle cell morphology and harbouring pigmented melanocytes. awareness of this histological variant is important in the differential diagnosis of spindle cell tumours of the mediastinum.- - - - - - - - - - ranking = 8.5keywords = spindle cell, spindle (Clic here for more details about this article) |
9/53. thymoma associated with hypogammaglobulinemia (Good's syndrome): report of a case.A 63-year-old man was admitted to our hospital for treatment of hypogammaglobulinemia with thymoma (Good's syndrome). Tests for immunological function showed an abnormality in humoral immunity with decreases in the proportion of cells bearing B-cell markers in the peripheral blood and bone marrow. The patient was found to have campylobacter fetus sepsis caused by the hypogammaglobulinemia due to humoral immunodeficiency, and he was given gamma-globulin supplement. thymectomy was performed due to enlargement of the thymoma after 4 years of follow-up and the pathological diagnosis was thymoma of the non-encapsulated, epithelial spindle cell type. Although there was no recurrence of thymoma, the hypogammaglobulinemia remained unchanged and the patient continued to suffer from repeated infections. Thus, we describe the case of a patient with Good's syndrome associated with independent humoral immunodeficiency in whom the effect of thymectomy for hypogammaglobulinemia was negative. In this respect, thymectomy was only beneficial when the thymoma proliferated and seemed to be more threatening than the hypogammaglobulinemia for the patient.- - - - - - - - - - ranking = 0.5keywords = spindle cell, spindle (Clic here for more details about this article) |
10/53. Pure red cell aplasia associated with thymoma.A case of thymoma with mixed spindle and lymphocytic variety along with acquired, secondary, chronic pure red cell aplasia is an uncommon entity. The presented case is a case of anterior mediastinal tumour with marked anemia. On histopathologic and hematological examinations, it proved to be a case of thymoma along with pure red cell aplasia. High index of suspicion, bone marrow examination, radiological including CT scan examination, total thymectomy after preparation with repeated blood transfusion remains the mainstay of treatment. Prolonged corticosteroid therapy leads to remission for upto ten months after operative intervention.- - - - - - - - - - ranking = 0.17906834273477keywords = spindle (Clic here for more details about this article) |
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