Abstract
Dear Sir,
A 21 year-old woman presented with a 5-month history of intermittent pain of the right index finger tip. On examination, there was severe tenderness on the radial side of her right index finger at the DIP joint level. A small tumour-like lesion with bony calcification was seen at the DIP level on plain X-ray (Fig 1) and on MRI. The site was explored under brachial block anaesthesia through a radial mid-lateral incision. The radial digital nerve was found to be elongated at the DIP joint level (Fig 2). This section of the nerve was resected and the 2 mm gap repaired by direct anastomosis with 10-0 nylon suture. After surgery, the pain completely resolved. The specimen was reported histologically to be similar to neuritis ossificans of the digital nerve (Isla et al., 2004), although zonal structuring was not clearly observed. The centre of the lesion consisted of bone tissue surrounded by infiltrating neutrophils, eosinophils and lymphocytes. The fascicle structure was positive for S100 protein and negative for MIB-1.
Previous authors have reported neuritis ossificans due to heterotopic ossification in the interfascicular space of the ulnar, median, tibial and sciatic nerves (Catalano et al., 1992; Isla et al., 2004; Rank and Rostad, 1998). This is the first report of intraneural ossification of the digital nerve, which is a mono-fascicular nerve.