Objective To investigate the clinicopathological change in primary rhabdomyosarcoma of the ear, and its differential diagnosis with infantile rhabdomyosarcoma, primary neuro-ectodermoma, and malignant rhabdomyoma. Methods Gross and microscopic examination and immunohistochemical staining were performed in 8 cases of primary rhabdomyosarcoma of ear. Results Seven male and one female patients with mean age of 7.4 years were found. The tumor was diagnosed as embryonal rhabdomyosarcoma in 7 patients, and botryoid rhabdomyosarcoma in 1 patient. Immunostaining revealed that vimentin and myoglobin were 100% positive, desmin in 75% and actin in 82%. Conclusions Although the histological appearance of primary ear rhabdomyosarcoma does not differ from those found in other soft tissues, its clinicopathological diagnosis may be difficult in some cases, and further immunohistochemical analyses, may be necessary for a correct diagnosis. Its differential diagnosis includes infantile rhabdomyofibrosarcoma, primary neuroectodermal tumor and malignant rhabdoid tumor.

AIM: To determine the role of the glycocalyx in microvascular permeability. METHODS: Dextran was intravenously injected and quatitatively examined in the rat transient cerebral ischemic model. At the same time, endothelial glycocalyx (anionic sites) was labelled with the probe cationic gold colloid (CGC) using post-embedding technique and examined with electron microscope. RESULTS: The labeling of CGC decreased significantly following ischemia, meanwhile, microvascular permeability to dextran increased. CONCLUSION:Endothelial glycocalyx is very sensitive to ischemia or anoxia. Its disruption may be the initiator of the dysfunction of endothelium and the determinant of increased permeability.

OBJECTIVETo study the clinicopathological features of epithelioid angiosarcoma (EA) and to propose its differential diagnosis.

METHODS15 EAs were observed by means of HE staining, immunohistochemical staining (ABC method) and in part by electron microscopy.

RESULTSTwelve cases occurred in men and three in women. Clinical symptoms included a focal mass with pain, weight loss and weakness. The tumors were located in the retroperitoneum (n = 3), extremities (n = 3), femur (n = 4), thyroid (n = 2), supraobit (n = 1), soft tissue of thorax (n = 1), soft tissue of neck (n = 1). Radiographic evaluation demonstrated solid to cystic neoplasms ranging from 3 to 20 cm in diameter. Histologically, the epithelioid cells were arranged diffusely or in nests with hemorrhage and focal necrosis. Atypical tumor cells lined the irregular spaces and single or small nests of cells grouped around a lumen containing red blood cells. FVIII, CD34, CD31,CK and EMA were positive in tumor cells and SMA was positive in pericytes. Ultrastructurally, intracytoplasmic vacuoles, Weibel-Palades, intermediate filaments and basal lamina could be seen. Surgical resection was the treatment of choice, occasionally with adjuvant chemotherapy. Follow-up. Two patients are presently alive 19 months and 7 years following diagnosis. Twelve died from 2 weeks to 38 months with a median interval of 19 months after lumpectomy. One patient was lost to follow up. There were 8 cases which had metastases to lungs, bones, lymph nodes and abdominal cavity.

CONCLUSIONSEA is a high-grade sarcoma. Endothelial derivation can be confirmed by immunohistochemical staining and ultrastructural findings. The differential diagnosis of EA includes metastatic carcinoma, epithelioid hemangioendothelioma, melanoma, epithelioid sarcoma etc.

Adult ; Aged ; Diagnosis, Differential ; Epithelioid Cells ; pathology ; Female ; Hemangioendothelioma, Epithelioid ; diagnosis ; Humans ; Immunohistochemistry ; Male ; Melanoma ; diagnosis ; Middle Aged ; Sarcoma ; diagnosis