RESUMEN
A series of 1,682 cases in the service of the Department of Pathology, Ramathibodi Hospital from 1977 to 1986 was studied and classified according to WHO histologic typing of soft tissue tumors. The findings revealed that the three most common benign soft tissue tumors were lipoma (50.6%), vascular tumors (17.4%) and neurofibroma (7.3%), whereas, the three most common malignant soft tissue tumors were unclassified sarcoma (16.5%), rhabdomyosarcoma (15.5%) and neurofibrosarcoma (10.7%). Lipoma occurred at any age group with a mean age of 40 years and affected males and females equally and common sites of involvement were neck (19.7%), back (19.7%) and upper arm (18.4%). Unclassified sarcoma was the most common among the malignant group accounting for 16.5 per cent of the total malignant soft tissue tumors. The age ranged from 7 to 70 years with a mean age of 27.4 years. The most common sites of involvement were the extremities (50%) especially the thigh.