Lipoma of the Middle Finger Hampering its Movements

Abstract

Dear sir, Lipomas are common soft tissue neoplasms and can be found anywhere in the body, especially in the head and neck region, as well as in the shoulder and back [1]. They are uncommon in the hand and are rarely found in the fingers with reported incidence of 1% [2]. According to WHO committee for the Classification of Soft Tissue Tumors, they are categorized into 9 entities, including lipoma, lipomatosis, lipomatosis of nerve, lipoblastoma, angiolipoma, myolipoma of soft tissue, chondroid lipoma, spindle cell/pleomorphic lipoma and hibernoma. Benign lipomatous lesions may also affect joints and tendon sheaths, either focally or diffusely [3]. Lipomas are often not considered in the initial differential diagnosis of digital swellings. We present a case with right middle finger lipoma involving the proximal interphalangeal joint. A 48-year-old male presented with swelling on the dorsomedial aspect of the proximal interphalangeal joint of the right middle finger, causing difficulty in finger movements (Fig. 1). The lesion had started one and a half year back and gradually increased in size thus causing discomfort in finger movements since last two months. Physical examination showed a 1.5 × 1.5 cm, nontender, subcutaneous swelling on the dorsomedial aspect of the proximal interphalangeal joint associated with some limitation of finger movements. Plain anteroposterior radiograph of the digit showed no invasion of the bone, thus excluding parosteal lipoma from the differential diagnosis. The patient was subjected to exploration of the finger under local anaesthesia using a longitudinal skin incision (Fig. 2). There was no difficulty in excising the swelling as its margins were free. It was excised completely and subjected to histopathology examination. After surgery, patient fully recovered the movements of the involved finger. Grossly, the swelling was 1.5 × 1.0 cm in size and was composed of fatty tissue. Histological results showed the swelling to be a lipoma. There was no evidence of recurrence or any restriction in finger movements during the two years of postoperative follow-up. Fig. 1 Lipoma of right middle finger Fig. 2 Lipoma protruding through incision Lipomas account for approximately 16% of soft tissue mesenchymal tumors. They are rarely encountered in the hand and are extremely rare in the digits. Neoplastic lesions (liposarcoma, lipoblastoma, Giant cell tumour, spindle cell lipoma, angiolipoma, and neural fibrolipoma) and non neoplastic lesions (implantation cyst, pyogenic granuloma, and nodular fasciitis) with clinical characteristics similar to those of a lipoma of the finger should be considered in the differential diagnoses of a mass in the finger. Careful dissection is necessary during the surgical procedure in order to avoid recurrence. Ultrasonography, computerized tomography, or magnetic resonance imaging are useful for more detailed investigations and differential diagnosis [4]. Although a lipoma in the finger is relatively rare, it should be included in the initial differential diagnoses of finger tumours. Although being rare entity, its awareness is imperative since the differential diagnosis from other soft tissue tumors is quite extensive so it should be included in the initial differential diagnoses of finger tumours.