Carpal tunnel syndrome caused by a giant lipoma of the hand: A case report

INTRODUCTION AND IMPORTANCE: Lipomas are common benign tumours which occur in up to 2% of the population. They are classified as giant when larger than 5 cm. Although they are usually asymptomatic, giant lipomas of the hand may cause compression of the underlying tissues. CASE PRESENTATION: A 62-year-old Caucasian male presented to the Plastic and Reconstructive Surgery outpatient clinic with numbness and pain in his left hand. The numbness in his fingers pointed to compression of the median nerve, as well as the ulnar nerve. He presented with a rapidly progressive swelling in his left palm. An MRI scan of the hand was made, which showed a lipoma of approximately 8,5 cm in diameter. The swelling was surgically removed and sent for histopathological analysis, which confirmed the diagnosis of benign giant lipoma of the hand. Two weeks postoperatively, pain and numbness significantly decreased. CLINICAL DISCUSSION: Neural injury in carpal tunnel syndrome is related to the duration and degree of compression. A giant lipoma is considered malignant until proven otherwise since variants with high potential for metastasizing exist. Distinguishing between a benign tumour and a malignant lipoma is essential, since a more radical treatment plan might be required. CONCLUSION: Giant lipomas of the hand are a rare cause of carpal tunnel syndrome and a malignant variant should always be suspected. A preoperative MRI scan should be performed. Rapid en bloc excision is necessary in case of compression of the underlying tissues.