Metachronous bilateral soft tissue sarcoma of the extremities.

BACKGROUND AND AIMS: Synchronous and heterochronous multiple soft tissue sarcoma of the extremities is very rare. Out of 1,201 of our patients, 4 patients presented with symmetrical bilateral soft tissue sarcoma of the extremities. The aim of this study was to identify possible reasons for this unusual manifestation of sarcomas.
MATERIALS AND METHODS: The patients' data was acquired by review of the patients' charts and follow-up information was gathered by phone calls to the patients or their relatives and their general practitioners.
RESULTS: All tumours were located at the extremities and were diagnosed as leiomyosarcoma in two patients, malignant fibrous histiocytoma and clear cell sarcoma in one patient each. No other individual or family history of cumulation of neoplasms was known in the patients. The median interval between the diagnoses was 3 1/2 years (range: 4 months to 9 1/2 years). In two patients a second primary sarcoma of the same entity was considered the most likely diagnosis, whereas in one patient a contralateral lymph node metastasis and in one other patient an atypical soft tissue metastasis had to be taken into account. A positive family history with a father with malignant fibrous histiocytoma may indicate a hereditary predisposition in one patient. Aside from irradiation effects, exposition to other carcinogenic agents or genetic predisposition, the reasons for the clustering of soft tissue sarcoma in one same patient remain still unclear. Only one patient, although suffering from disseminated metastatic disease was living at follow-up time, the other three patients had already died.
CONCLUSION: The interpretation of the bilateral manifestation of soft tissue sarcoma remains open, but predicts an unfavourable outcome.