Osteoid osteoma of distal phalanx: A rare disorder and review of literature
A 27-year-old right handed man refer to orthopedic uniclinic of Isfahan Al-zahra hospital on March 2011 with a 4 years history of gradual increase in size and deformity of the distal part of his left middle finger. Pain was a marked feature that disabled his life and was only relieved temporarily by analgesic and aggregated in nights. Twelve months earlier he had been treated for local infection, initially with a course of antibiotics. This treatment had been unsuccessful.\nOn examination, the finger was enlarged beyond the distal interphalangeal joint and clinically looked like an isolated clubbed digit. The pulp was big and there was increase in both longitudinal and transverse curvature of the nail-plate. The skin at the base of the nail-plate was swollen and shiny and there was a small amount of fluctuation. The nail-fold angle was obliterated. The patient did not report any previous trauma or infection; laboratory data, including laboratory tests for inflammation and rheumatic conditions, were normal, and CRP was negative. The middle finger was warm on palpation, and there were no evident superficial reticular veins. There was a slightly reduced range of motion in the distal interphalangeal joint compared to the contralateral hand. No satellite lymphadenopathy was observed.\nRadiographs revealed soft tissue edema on volar and dorsal side of finger. An oval shaped sclerotic mass in base of volar aspect of distal phalanx with tinny radiolucent border was seen []. In MRI, there was a 1.2 cm mass-like lesion in volar aspect of proximal half of the distal phalanx, being isosignal to muscles in T1W, and hyper in T2W images, causing saucerization of anterior surface of the bones. Nidus was not seen in plain radiography, but edema was obvious in MRI []. Unfortunately, we have no CT scan of finger in this patient.\nBased on clinical and radiographic findings, the presumptive diagnosis of osteoid osteoma was made (however other conditions, including infection and giant cell tumor were considered) and the patient underwent surgery. Through an approach on the volar side of the distal phalanx a hole was made in the area of osteosclerosis, thus revealing a small, less dense and relatively hyperemic area that flexor profundus tendon was attached to it. Then mass was removed en-block and Curettage was performed with a small curette and then tendon was attached to bone with tension suture, and specimen referred to pathology lab. Histological examination confirmed the diagnosis of osteoid osteoma, since the typical nidus was found in the histological specimen [].\nThe limb was immobilized with dorsal short splint for repair of tendon. In the first days following surgery, the pain with which the patient used to live with had already disappeared.\nThe patient, recently was seen 7 days after the operation, had no pain. Aspect and size of the finger and of the nail were similar to the contralateral one, having normalized a few months after surgery.