This non-tender, freely mobile, rubbery-feeling nodule is a classic lipoma. Diagnostic contenders include epidermal cyst and cutaneous metastases.
A 69-year-old man with a past history of non-melanoma skin cancer presented for a total body skin check. A large asymptomatic nodule was discovered on his lower back.
Key point: The nodule was solitary, 12.3 cm by 9 cm, non-tender, freely mobile, and rubbery-feeling. The differential diagnosis usually consists of: epidermal cyst, lipoma, and cutaneous metastases. This is a classic lipoma. The patient reported that he had a “benign fatty tumor” removed from his flank many years previously.
Treatment: The treatment of choice is simple, complete excision. However, the patient was not interested in pursuing this option.
Note: The lack of a punctum, the sheer size of the lesion, and the past history of lipoma removal all favor the diagnosis of lipoma.