Acral Myxoinflammatory Fibroblastic Sarcoma

This rare low-grade sarcoma was identified by Meis-Kindblom and Kindblom in 1998. The tumor presents as a painless subcutaneous mass of months or years duration. Approximately 30% of these tumors occur in the foot and ankle, 65% in the hand and wrist, and the rest in other sites. Patients are in their middle adult years (range third to 9th decade, median 53 years) and males and females are equally affected.

The lesions average 3 cm in size. The mass is poorly circumscribed and subcutaneous, leading to frequent misdiagnosis as ganglion cyst or tenosynovitis.

Due to the innocuous presentation the initial surgical margins are frequently inadequate. Recurrence is observed in 60 - 70 percent of cases. Approximately one quarter of the cases require amputation due to recurrent local recurrance. Metastasis is infrequent, but tumor spread to regional lymph nodes and lung have been reported.

Appropriate management begins with the recognition of the malignant potential of seemingly innocent masses. MRI exam will demonstrate the extent of the tumor and the regional lymph nodes and chest should be assessed. Excision with a wide margin and long-term follow-up is required.

Prognosis is similar to other low grade sarcomas, with two-thirds of patients alive without disease and the remainder alive with disease at five-year follow up.

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