Fibrolipoma of Flexor Digitorum Profundus Tendon of Ring Finger Causing Triggering and Intermittent Carpal Tunnel Syndrome

INTRODUCTION: Lipomas are most common soft-tissue tumors but rarely are found to be symptomatic. <1% of lipomas are found in hand. Subfascial lipomas can cause pressure symptoms. Carpal tunnel syndrome (CTS) can be idiopathic or secondary to any space-occupying lesion. Triggering usually occurs due to inflammation/thickening of A1 pulley. Most have reported a lipoma in distal forearm or near median nerve, leading to triggering of index or middle finger and carpal tunnel symptoms. All the cases reported had either an intramuscular lipoma in flexor digitorum superficialis (FDS) tendon slip of index or middle finger, with or without accessory belly of FDS muscle or a neurofibrolipoma of the median nerve. In our case, the lipoma was under palmer fascia, in flexor digitorum profundus (FDP) tendon sheath of fourth finger causing triggering of the ring finger and CTS symptoms in flexion of the ring finger. Hence, this is a first report of this kind in the literature. CASE REPORT: We hereby report a one of its kind case in which a 40-year-old Asian male patient had triggering of the ring finger with associated intermittent CTS symptoms, on making a fist, secondary to space-occupying lesion in palm, which was diagnosed by ultrasound as lipoma in FDP tendon of the ring finger in palm. This lipoma was surgically removed by AO ulnar palmer approach and carpal tunnel was decompressed. Histopathology report confirmed the lump to be fibrolipoma. The patient had complete relief of symptoms postoperatively. At 2 years follow-up, there was no recurrence.