Digital papillary adenocarcinoma: a case report

Abstract

Introduction Digital papillary adenocarcinomas are rare tumours of eccrine sweat gland origin usually occurring on the fingers and toes and adjacent parts of the palms and soles. Men are more commonly affected than women with a mean age of incidence of 52 years. They can have an indolent course and patients usually present with a painless solitary mass. Reports show they have a high recurrence rate and a tendency for deep infiltration into soft tissue and bone with about 15% of patients developing metastatic disease. These tumours were thought to have a benign counterpart, i.e., digital papillary adenoma, but none of the histological or clinical parameters examined in a study of 67 cases was predictive of recurrence or metastatic potential, thus all lesions are considered to be potentially malignant. Treatment is by wide local surgical excision which may result in amputation of the digit. Clinical history The case of digital papillary adenocarcinoma is reported in a 53-year-old gentleman who was referred by his GP to the surgeons for excision of a right fingertip lesion that was thought to be an intraepidermal cyst. A wide excision was performed. Pathological features Macroscopically the lesion was cystic and measured 10 mm in diameter containing tan mucoid material. Sections showed an encapsulated cystic tumour lined by a multilay-ered epithelium with pseudopapillary and solid glandular growth patterns. The solid glandular areas had a cribriform architecture. Squamous metaplasia, focal necrosis and numerous mitotic figures were present. No soft tissue or bone involvement was seen in this case. Conclusion The indolent clinical course of these tumours and occasional benign morphology increases the chances of a mistaken diagnosis of a benign lesion, making it quite important to recognise this entity, thus ensuring patients receive appropriate therapy and follow-up. In this case, despite the degree of atypia, the lesion was well clear of the surgical margins and there was no invasion into blood vessels, surrounding soft tissue or bone.