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Monday, August 09, 2004
Smooth Muscle Tumours
Paal 2001
Kilpatrick 1994
- Angioleiomyoma (angiomyoma, vascular leiomyoma)
- 4.4 % of benign soft tissue tumours. Most angioleiomyomas occur in the extremities, especially the lower extremities. Between fouth and sixth decades. Painful lesion. most are less than 2 cm. Three histologic subtypes: Solid (66%), venous (23%), cavernous (11%). IHC: positive for SMA, vimentin, collagen type IV. Negative for HMB-45.
- Leiomyoma of deep soft tissue
- Leiomyomas of deep soft tissue are very rare and the existence of them are controversial. THey arise in the deep subcutis or skeletal muscles of the extremities. They affect both sexes equally, whereas those arising in the retroperitoneum or abdominal cavity occur exclusively in women.Mean diameter 7.7 to 16.2 cm. Mitoses number is less than 1/50 HPF. In peritoneal / retroperitoneal lesions in female, mitose may be up to 5/50 HPF. No necrosis.ICH: positive for actin, desmin, h-caldesmon. Negative for S100. Local recurrence is rare.
- Leiomyosarcoma
- Soft tissue leiomyosarcomas occurs usually in middle-aged or older women. Leiomyosarcoma is predominant sarcoma arising in retroperitoneum or large blood vessels. Majority of retropetitoneal and inferior cena cava leiomyosarcomas occurs in women. Sarcomas of pulmonary artery other larger artery do not have the features of leiomyosarcoma, and most of them are better classified as intimal sarcoma. Tumours in inferior vena cava may obstruct hepatic vein, producing the Budd-Chiari syndrome. The tumour margin is commonly well-circumscribed, although infiltrativeness may be found. Histopathology may reveal hemangiopericytoma-like arrangement, myxoid change, necrosis,hyalinization, and non specific defifferentiated pattern. IHC: Positive for SMA, desmin, h-caldesmon. Although not absolutely specific, positivity for two of them are supportive. Negative for KIT(CD117), in contrast to GIST. Regional lymph node metastases are rare. Metastases occurs in the lungs, liver, skin, soft tissue, and bone. In immunocompromised patients, leiomyosarcoma may arise in parenchymal organs. They are predominant in children and young adults and are associated with EB virus. They may be multifocal.
Paal 2001
Kilpatrick 1994
Posted by: Ds20040999 / 2:34 AM 
