Posttraumatic intraosseous epidermoid inclusion cyst. A case report and short literature review

Epidermoid bone inclusion cysts are pathological structures bordered by a layer of stratified squamous epithelium containing keratin debris. They are also called epidermal bone cysts. Intraosseous epidermoid cysts are rare entities; these lesions may occur as a result of trauma (puncture wound or pressure erosion).They appear to be well defined, translucent lytic lesions with sclerotic margins on imaging studies. The most frequent sites affected are: the distal phalanx and the calvaria - intradiploic, but a few cases of larger bone involvement have been reported. The imagistic differential diagnosis of this lesion includes intraosseous extension of a glomus tumor, enchondroma, osteoid osteoma, acral metastases, some primary vascular bone tumors, giant cell reparative granuloma, subungual nodular melanoma or other lytic non-neoplastic lesions such as osteomyelitis. We present the case of a 70-year-old man experiencing anxiety and pain due to distal phalanx expansion of the IV digit, following hand trauma. An X-ray was performed, showing a radiotransparent lesion located in the distal phalanx. An intramedullary inclusion cyst must be taken into account as a clinical differential diagnosis. Due to the extensive destruction of the distal phalanx, amputation was necessary. Gross examination of the surgical specimen revealed a cystic lesion that contained whitish, creamy material with extensive necrotic areas. Microscopic examination revealed a ruptured intraosseous epidermoid inclusion cyst, which was successfully excised.

Intersphincteric epidermoid inclusion cyst: report of a rare case

Epidermoid inclusion cysts of the perineal region are a rare entity, which require appropriate diagnosis and management. Here we describe the unusual case of a large protruding epidermoid inclusion cyst originating from the intersphincteric anal plane, which was mobilized and excised successfully. Essential investigations to ensure accurate diagnosis in addition to surgical technique to reduce recurrence and patient morbidity are described in this case report.