Malignant fibrous histiocytoma of the mediastinum

Mediastinal malignant fibrous histiocytoma developing from a foreign body granuloma

A patient with mediastinal malignant fibrous histiocytoma (MFH) apparently developing from a foreign body granuloma is reported. A 72-year-old man was admitted to our hospital complaining of generalized fatigue and palpitations. He had undergone surgery for pulmonary tuberculosis 46 years previously. Radiography and computed tomography of the chest showed a round 5-cm mass with marginal calcification in the right side of the anterior mediastinum. The mass was resected completely via median sternotomy. Intraoperative diagnosis of foreign body granuloma was made, based on gauze fragments found in the mass and intraoperative pathologic findings suggesting benign granulation tissue. The postoperative histopathologic diagnosis was myxoid MFH. To our knowledge, mediastinal MFH developing from a foreign body granuloma has not been reported previously.

Malignant fibrous histiocytoma in the anterior mediastinum

The origin of a malignant fibrous histiocytoma in the anterior mediastinum is rare. A 71-year-old man was referred to our department for treatment of a tumor 15 cm in diameter originating in the anterior mediastinum. Malignant fibrous histiocytoma was suspected after a percutaneous needle biopsy. Systemic screening showed no other organ involvement, and the tumor was considered to be a primary mediastinal tumor. The tumor, resected through a median sternotomy, was well encapsulated and resection was complete. The pathological diagnosis was malignant fibrous histiocytoma originating in the anterior mediastinum.

Spindle cell thymic carcinoma: clinicopathologic and immunohistochemical study of a distinctive variant of primary thymic epithelial neoplasm

We report 16 cases of a distinctive variant of primary thymic epithelial neoplasm characterized by prominent spindling of the tumor cells. The patients were seven women and nine men aged 23 to 82 years (mean, 54 years). The lesions presented as anterior mediastinal masses without clinical or radiographic evidence of tumor elsewhere. Most patients had chest pain, dyspnea, and cough; in five patients, the tumors were asymptomatic and were discovered on routine clinical examination. Grossly, the lesions were firm, well-circumscribed, and locally infiltrative, and had a firm cut surface with foci of hemorrhage, necrosis, and cystic changes. Most of the tumors were treated by complete surgical excision. Histologically, they were characterized by a spindle cell proliferation showing varying degrees of atypia and mitotic activity. In 12 cases, transitions could be seen with areas that showed the features of conventional spindle cell thymoma. In two cases, areas showing features of poorly differentiated (lymphoepitheliomalike) carcinoma and anaplastic carcinoma could also be observed. Immunohistochemical studies in 10 cases showed strong positivity of the spindle tumor cells for CAM5.2 cytokeratin, and negative staining for a panel of antibodies including epithelial membrane antigen, carcinoembryonic antigen, actin, desmin, vimentin, S-100 protein, HMB45, CD34, CD5, and CD99. Clinical follow-up of eight patients showed an aggressive biologic behavior with recurrence, metastasis, and death by tumor in five of them 2 to 5 years after diagnosis. Based on these findings, the present tumors are interpreted as an unusual spindle cell variant of thymic carcinoma. The close association of these cases with areas showing the features of spindle cell thymoma within the same tumor mass suggests that some of these lesions may arise as a result of malignant transformation in a preexisting spindle cell thymoma.

Resection of malignant fibrous histiocytoma invading the thoracic aorta

We report a case of surgically resected malignant fibrous histiocytoma which arose in the posterior mediastinum. Tumor removal with the required sufficient-margin and the resection of the affected thoracic aorta, led to flaccid paraplegia below the tenth thoracic level. This patient is now surviving with no evidence of recurrence at 42 months after the operation. Although malignant fibrous histiocytoma in the thorax generally shows a poor prognosis, this patient with complete resection could have a relatively long survival.

Pleomorphic large cell lymphomas of the mediastinum

Nine cases of primary non-lymphoblastic, non-Hodgkin's large cell lymphomas of the mediastinum characterized by a highly pleomorphic histologic appearance are described. The patients, four women and five men, were aged 30 to 65 years. All patients presented with symptoms referable to their tumors, including cough, chest pain, dyspnea, pleural effusion, and superior vena cava syndrome. Clinical and pathologic staging in all patients showed that the bulk of the tumor was confined to the chest cavity at the time of initial diagnosis, with local infiltration into the neck, lung hilum, and surrounding mediastinal structures. Three different histological growth patterns were observed: one composed of a diffuse proliferation of pleomorphic, highly atypical cells with bizarre nuclear features that closely resembled a high grade sarcoma; another one composed of sheets of large, epithelial-appearing atypical cells suggestive of anaplastic carcinoma; and another pattern characterized by a pleomorphic proliferation of large lymphoid cells admixed with numerous scattered Reed-Sternberg-like cells reminiscent of the lymphocyte-depleted variant of Hodgkin's disease. Immunohistochemical studies on paraffin-embedded tissue sections in all cases showed positive staining of the tumor cells with CD20 and CD45 antibodies and negative staining with a large panel of markers, including broad-spectrum keratin, CAM 5.2, carcinoembryonic antigen, epithelial membrane antigen, vimentin, actin, desmin, HMB 45, S-100 protein, CD3, CD15, CD30, and CD45RO. Because of their location restricted to the anterior mediastinum, frequent lack of recognizable lymph node architecture, and bizarre cytologic features, the present group of lesions posed difficulties for diagnosis, their correct identification was achieved through the application of a panel of immunohistochemical markers. An awareness of these unusual histologic appearances of primary large cell lymphoma in the mediastinum and inclusion of a broad panel of lymphoid markers are therefore recommended for the evaluation of pleomorphic, undifferentiated malignant neoplasms of this anatomic region.

Malignant smooth muscle tumors presenting as mediastinal soft tissue masses. A clinicopathologic study of 10 cases

BACKGROUND

Smooth muscle tumors presenting as mediastinal soft tissue masses are extremely rare and often are mistaken for other neoplastic conditions.

METHODS

Ten cases of patients with malignant smooth muscle tumors presenting as mediastinal soft tissue masses were studied and correlated with their clinical behavior. Tissues were examined histologically and with immunohistochemical stains in all cases, and by electron microscopy in two cases.

RESULTS

The patients' ages ranged from 26 to 71 years (mean, 56 years); three were women, and seven were men. Three cases were located in the anterior mediastinum and seven in the posterior mediastinum. The patients with anterosuperior mediastinal tumors all presented with signs and symptoms referable to their lesions; the patients with posterior mediastinal masses (with the exception of one) were all asymptomatic. Grossly, the lesions were well circumscribed and unencapsulated, ranging from 6 to 18 cm in greatest dimension and showed a homogeneous, rubbery cut surface with prominent cystic and myxoid areas. The tumors in all patients appeared to arise from the soft tissues within the mediastinum and were unrelated to adjacent structures. In three patients, the tumors compressed and displaced the esophagus without infiltrating its wall, and in one patient, the tumor was found in close proximity, although unattached, to a large vessel. Histologically, the lesions exhibited a spectrum of morphologic appearances that ranged from low grade leiomyosarcoma with mild-to-moderate nuclear atypia and low mitotic activity (< 3/10 high power fields [HPFs]), to high grade tumors with marked nuclear pleomorphism, extensive areas of necrosis, and high mitotic activity (> 10 mitoses/10 HPFs). One case was characterized by a striking epithelioid morphology with large, round cells arranged in small clusters; another was associated with an incidental microscopic focus of thymic seminoma in the adjacent thymus. Immunohistochemical stains in all cases showed positive labeling of the tumor cells with smooth muscle actin, desmin, and vimentin antibodies. Electron microscopy in two cases showed features of smooth muscle differentiation, i.e., spindle cells surrounded by basal lamina material, immature cell junctions, and abundant intracytoplasmic filaments with focal condensations. All patients were treated with surgical excision. On follow-up, three patients with Stage IIIb and IVa tumors died 2-7 years after surgery, and two patients with Stage Ib and IIb were alive and well 4 and 6 years after surgery, respectively.

CONCLUSION

Leiomyosarcomas may arise as primary tumors originating from mediastinal soft tissues in both anterior and posterior compartments. Because of their large size and frequent areas of cystic and myxoid degeneration, they may be confused histologically with neural or other neoplasms. As with their counterparts in other soft tissue locations, histologic grade and clinical stage are the most useful parameters for assessing prognosis.

Malignant fibrous histiocytoma originating in the mediastinum: report of a case

Malignant fibrous histiocytoma (MFH) is a tumor which most often develops in the soft tissues of the extremities and retroperitoneum, but very rarely originates in the mediastinum. We report herein the case of a 63-year-old man who underwent surgical resection of a rapidly growing tumor in the right thoracic cavity which was diagnosed as an MFH of mediastinal origin on the basis of histological findings, the definitive diagnosis ultimately being made by specific immunostaining.

An autopsy case of malignant fibrous histiocytoma of the mediastinum, presenting multiple metastases to the small intestine and to the brain--a rare case report with a review of the literature

An autopsy case of malignant fibrous histiocytoma (MFH) of the mediastinum in a 25-year-old Japanese man is described. He initially complained of general fatigue and intermittent tarry stool, and was radiographically revealed to have a huge mass within the mediastinum as well as multiple nodules within the abdominal cavity, respectively. The mediastinal tumor could not be resected because of direct tumor invasion into surrounding tissues. Within the abdominal cavity, three distinct tumor nodules were discovered in the jejunum, which could be resected surgically. Histopathologically, the components of both lesions were very similar, and the present case was interpreted as multiple metastases of mediastinal MFH to the intestinal wall. In spite of various kinds of treatment, the mediastinal tumor rapidly enlarged, causing SVC syndrome. Brain CT findings suggested multiple metastases which were considered to be the cause of death. Autopsy confirmed that the main tumor nodule was located within the mediastinum, with brain metastases. The present case of mediastinal MFH is considered to be the youngest case as well as the first case presenting intestinal metastases.

Primary malignant fibrous histiocytoma of the mediastinum

A malignant fibrous histiocytoma of the mediastinum was successfully treated by surgery and radiotherapy. Magnetic resonance imaging was able to show the site of invasion, the two different components of the tumour, and the blood supply.

Malignant fibrous histiocytoma of the mediastinum

A case of malignant fibrous histiocytoma of the mediastinum presenting with unusual features of fever and leucocytosis is reported. This is the youngest patient reported in the literature who had this tumour in the mediastinum.

Primary aortic malignant fibrous histiocytoma: a successfully treated case by surgical excision

A man with a short history of retrosternal discomfort and weight loss was found to have a large malignant fibrous histiocytoma of the ascending aorta. The tumor was resected on partial cardiopulmonary bypass. We believe this is the only malignant fibrous histiocytoma of the ascending aorta reported and successfully treated in the literature.

Xanthogranulomatous malignant fibrous histiocytoma arising from posterior mediastinum

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Malignant mediastinal myxoid tumor and renal cell carcinoma

A 69-year-old man with a malignant mediastinal myxoid tumor and a right renal cell carcinoma died from bilateral compression atelectasis after a two months' clinical course. The mediastinal tumor simulated a myxoid malignant fibrous histiocytoma (MFH) because of great pleomorphism of tumor cells, although the histological differential diagnosis of myxoid MFH, other myxoid sarcomas, and metastatic renal cell carcinoma was very difficult. Three reported cases of primary mediastinal MFH are briefly reviewed.