Vivek Sharma, Ravinder Singh, Amit Mittal, Ashwani Ummat, Arun Rathee.
Implantation Dermoid of the Distal Phalanx: A Missed Diagnosis.
J Pioneering Med Students Jan ;4(4):180-3.

Epidermoid inclusion cysts are benign lesions that occasionally occur in the distal phalanges of the fingers. A 30-year-old man presented with swollen and tender distal phalanx of the left middle finger. Radiographs showed an expansile lytic lesion in the tip of the distal phalanx with associated cortical erosions and minimal soft tissue component. CT scan revealed a well–defined lytic lesion with broken cortex at one place in the distal phalanx of the affected finger probably due to trauma. From clinical and radiological examination, a giant cell tumor, possibly aggravated by his injury, was suspected. The differential diagnosis included an inclusion cyst or a chronic infection. During operation, a cystic lesion containing creamy material was obtained from within the bone which was sent for culture and sensitivity. After aspiration of the creamy material, a thick, yellow rind within the bone was completely removed and sent for histopathology. Bone graft was taken from the ipsilateral proximal ulna and suitably shaped to fill the cavity left after thorough curettage. Histopathology showed findings consistent with inclusion dermoid cyst. The patient recovered uneventfully, with normal functional digit and satisfactory radiographs. Epidermoid cysts of the bone are rare and mainly involve skull and phalanges. Diagnosis of such lesions is challenging and misdiagnosis may result in an unnecessary digital amputation.

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