Desmoplastic melanoma arising in the ankle

Desmoplastic melanoma (DM) is an uncommon but potentially devastating malignancy that can be cured with early recognition and surgery. DM often occurs in elderly men and develops on sun-exposed areas with the head and neck being the most common site of origin followed by the extremities and trunk. We report a rare case of DM occurring in the ankle in an 85-year-old woman. Magnetic resonance imaging of the affected ankle showed a 4.3 x 4.3 x 2.5 cm sized mass which was located in the subcutaneous region, attached to lower leg muscles, the fibula, and the calcaneus. No metastasis to the lung, liver, bones or abdominal lymph nodes was found. In spite of below knee amputation, the patient died of lung metastases 10 months after surgery. Among several factors causing early death of the patient, a large size, a deep location and rapid growth of the tumor seem to be most important.