Plantar fibromatosis masquerading as metastatic melanoma

We present the evaluation and treatment of a 59-year-old male with a medical history significant for multiple recurrences of malignant melanoma. The patient was found to have increased focal uptake of his right foot on fluorodeoxyglucose positron emission tomography. Given the patient's clinical history, the increased uptake was suspected to be recurrence of his disease. The nodule was surgically excised and was later pathologically diagnosed as benign plantar fibromatosis. To our knowledge, only one other case report of plantar fibromatosis demonstrating increased fluorodeoxyglucose positron emission tomography uptake exists. Given the distinct prognostic differences between plantar fibromatosis and recurrent malignant melanoma, clinicians should be aware of the possibility of such false-positives with fluorodeoxyglucose positron emission tomography during oncologic surveillance.