[Pulmonary epithelioid hemangioendothelioma: a clinicopathological analysis].

OBJECTIVE: To report 3 cases of pulmonary epithelioid haemangioendothelioma (PEH) and therefore to improve the understanding of this tumor. METHODS: The clinical pathological features of 3 cases of PEH were described and related literatures were reviewed. RESULTS: The etiology of this rare disease remained unknown. Symptoms were scanty and usually mild. Chest radiograph or computed tomography usually revealed multiple bilateral pulmonary nodules. Histologically, crown-like clusters of epithelioid tumor cells or spindle cells were filled in the alveoli at the periphery of the tumor nodules, while the central part of the nodules contained myxoid to hyaline matrix. Tumor cells generally lacked pleomorphism, mitotic activity and necrosis. They were immunohistochemically positive for CD(31) and CD(34). CK staining was positive in some cases. There was no effective treatment for this disease and its prognosis was unpredictable. CONCLUSIONS: PEH is a low grade malignancy and represents a distinct clinical pathological entity. It is rare and often misdiagnosed as other pulmonary diseases.

Primary malignant bone neoplasm: a case report of dedifferentiated chondrosarcoma in the rib and review of the literature.

Dedifferentiated chondrosarcoma (DDCS) is a rare but highly malignant primary bone neoplasm, which is resistant to radiotherapy and chemotherapy. There remains uncertainly as to the best treatment of this disease and how to improve its prognosis. In this paper we reported a case of DDCS and reviewed the related literatures in order to provide references to throw a light on the histogenesis, diagnosis and therapy of this disease.

[Pathological and ultramicrostructural changes of tissues in a patient with severe acute respiratory syndrome].

OBJECTIVE: To study the morphological, ultramicrostructural and pathological changes of tissues from a patient with severe acute respiratory syndrome (SARS). METHODS: One autopsy case of diagnosed SARS was investigated. Lung puncture was performed immediately after the patient died, and the autopsy was done after 12 h. The specimens from lymph nodes, spleen, small intestine, colon and bone marrow were studied by immunohistochemical technique. The antibodies used included CD20, CD45RO (UCHL-1), CD4, CD8, CD68 and CD34. RESULTS: The principal lesions of the SARS case consisted of acute lobular intrastitial pneumonia, hyaloid membranes of pulmonic alveoli and hyperplasia and shedding of alveolar epithelium of. Virus-like inclusions occasionally contained cytoplasm of the alveolar epithelium, which were positive by histochemical staining. The adjacent blood-vessels were changed by hyperplasia and enlargement. The structures of lymph nodes and spleen were damaged with lymph follicles depletion and splenic nodules atrophy. The specific changes included reduction of lymphocytes and hyperplasia of histiocytes, depletion of the follicles of small intestine and colon wall, decreased hyperplasia of the bone marrow and increased number of the megakaryocyte. Meanwhile, in the immunohistochemical study, CD(20)(+) B cells were fully expressed in lymph nodes and spleen, and the CD45RO (UCHL-1)(+) T cells were scatteredly expressed. The number of CD4(+) help T cell was markedly decreased, while the number of CD8+ poisonal T cells increased, and the ratio of the former and latter was no more than 0.5. Under the electronic microscopy observation, virus-like particles with 80 - 160 nm diameter and halo or garland envelope were found in mononuclear macrophage and cytoplasm of alveolar epithelium. CONCLUSION: The specific lesions of SARS consist of lobular intrastitial pneumonia with the formation of hyaline membranes of lung, haemorrhage, necrosis, inflammation of blood vessels and the damages of extralung lymphohemopioetic system. The damages were very similar to the pathological features of tissues infected by human immunodeficiency virus, in which numbers of T cells decreased and CD(4)(+) T cell/CD(8)(+) T cell ratio was no more than 0.5. According to the virus-like particles found in lung of the SARS case, it is considered that these virus-like particles may be a new kind of coronavirus which caused the "atypical pneumonia".