Spindle cell melanoma masquerading as a lipoma: an interesting presentation of a rare cancer

Abstract

Background: Overall survival is directly correlated to melanoma thickness and definitive surgical excision. Spindle cell melanoma is a rare subtype of malignant melanoma and particularly difficult to diagnose. Identification of histopathological features and referral to specialists are essential. Case presentation: We describe the case of an 86-year-old male who presented to his family medicine physician with complaints of a large 40 mm mass on his right posterior trunk which was clinically diagnosed as a lipoma. This mass was subsequently removed in his family physician’s office as an office procedure. Less than eight months post-excision, the tumor had erupted through the incision site. At time of surgical oncologist evaluation, the tumor was pedunculated and measured 92 mm at its greatest diameter. This tumor was subsequently biopsied to reveal spindle cell melanoma with thickness of at least 22 mm. Wide local excision was performed with complete removal of the tumor with negative margins. Conclusion: Our report supports the importance of early and correct diagnosis of cutaneous melanoma which can often be mistaken for other cutaneous lesions, both benign and malignant. In these situations, it is important to obtain a tissue biopsy and consult with specialists in pathology and surgical oncology/dermatology to ensure timely, appropriate treatment.