Adult-Onset Subungual Eccrine Angiomatous Hamartoma on Right Great Toe: A Case Report

Abstract

Eccrine angiomatous hamartoma (EAH) is a benign skin nodule characterized by the proliferation of eccrine glands and vascular structures in the dermis. It usually presents as a single papule or nodule on the extremities, and usually arises at birth or in early childhood, but several cases which appeared in adulthood have been reported. A 52-year-old female presented with a tender subungual nodule on the right great toenail for 3 months. Skin biopsy from the lesion showed proliferation of eccrine glands and capillaries in the dermis, and immunohistochemistry confirmed the diagnosis of EAH. We excised it as a treatment, and at the 3-month follow-up, pain by her lesion has resolved without any adverse effects. Our presented case is an adult-onset EAH that occurred as a subungual lesion. Unlike the previous cases, it did not cause any nail deformity or destruction and initially was misinterpreted as some other subungual tender nodule. To the best of our knowledge, we report the first case of adult-onset subungual EAH without nail deformity.

Keywords: Capillary; Eccrine gland; Hamartoma; Nail abnormalities; Nails; Neoplasm.

Fig. 1. (A) A tender, solitary nodule on the right great toenail bed of 52-year old woman (arrow). (B) A well-demarcated nodule after partial nail avulsion. We received the patient’s consent form about publishing all photographic materials.

Fig. 2. Histopathological features of the lesion. (A) Scanner view showing epidermal acanthosis (H&E, ×10). (B) Proliferation of vascular structures in the superficial dermis (H&E, ×100). (C) Proliferation of eccrine sweat glands in the deep dermis (H&E, ×100).

Fig. 3. Immunohistochemical studies of the lesion. (A) Proliferated vascular structures showing positivity for CD31 on immunohistochemistry are intermingled with eccrine glands in the mid dermis (CD31, ×200). (B) Proliferated vascular structures in the same area shows negativity for D2-40 (podoplanin) on immunohistochemistry (D2-40, ×200). (C) Eccrine glands proliferation in the deep dermis shows positivity for carcinoembryonic antigen (CEA) on immunohistochemistry (CEA, ×200). (D) Eccrine glands proliferation in the deep dermis shows positivity for S-100 on immunohistochemistry (S-100, ×200).