Giant Hand Lipoma Revisited: Report of a Thenar Lipoma & its Literature Review

Abstract

Dear Sir, Lipoma is the commonest soft-tissue tumor occurring almost in any part of the body [1]. A special subtype—‘giant lipoma’ merits mention as it accentuates the presenting symptoms and offers diagnostic dilemma regarding its benign nature to the surgeon. In this paper we present a case of a giant hand lipoma. Sixty-one years old female presented with 4 × 4 cm swelling at her right thenar eminence since last 5 years (Fig. 1a). It was hindering her grasping activities so much so that she had to quit her job. Hand x-ray showed a diffuse soft-tissue shadow. Contrast-enhanced-magnetic-resonance-imaging showed 9.5 × 4.5 × 4cm homogeneous soft-tissue lump having superficial and deep components (Fig. 1b). It was masquerading further through 1st, 2nd till the 3rd web-spaces along the flexor digitorum tendons. Neuro-vascular structures were free. Hand-exploration through palmer-crease was performed to achieve its complete excision (Fig. 2a and b). She had a good postoperative recovery. Histopathology confirmed the benign nature of the lipoma. Fig. 1 a Thenar lipoma. Note its clinical extent. b MRI showing the complete extent of the giant lipoma. Note the coronal and the sagittal sections showing lipoma engulfing the tendons of flexor digitorum Fig. 2 Per-operative photograph showing initial part of lipoma projecting thru skin crease incision (a), followed by complete excision (b). c Completely resected specimen of giant lipoma. Note 9.5 × 4.5 × 4 cm ... It’s an interesting fact that hand lipomas are rare in spite of decent quantity of fat in palm region (1–3.8 %) [2]. Oster noted that the hand lipomas are peripherally positioned [2]. Their peripheral location may be due to thick mid-palmer fascia. They are unique in their presentation owing to limited palmer spaces (for their growth) surrounding important neuro-vascular structures. Mason further classified hand lipomas into superficial and deep palmar lipomas; the deeper ones are less common than the superficial ones and have complex variable morphology as noted in our patient [3]. Ones greater than 5 cm are designated as ‘giant’ lipomas and many of them have well-differentiated liposarcomatous components, which are difficult to differentiate from their benign counterparts [3, 4]. Patient usually approaches surgeon for compressive neurological symptoms, cosmesis, and fear of cancer (the 3 ‘C’s). Clinically small appearing hand lipomas may actually just be ‘a tip of ice-berg’ as found in our patient. Hence, they need a detailed imaging study by an MRI. Surgical excision remains the gold-standard for symptomatic and giant lipomas of the hand. Giant lipomas up to 8 cm have been reported in the literature [3, 4]. Our patient had 9.5 × 4.5 × 4 cm lipoma (Fig. 2c). Considering the ‘intricate anatomy’ of hand, a high quality imaging is necessary for their detailed study. A meticulous margin-free resection is the key for good results.