Eccrine Angiokeratomatous Hamartoma: Report of A Case with Brief Review

Eccrine angiokeratomatous hamartoma is a newly recognised vascular lesion of the skin, with the first case being reported only in 2006. It has a distinctive histology with features derived from two well established vascular lesions affecting the skin: solitary angiokeratoma and eccrine angiomatous hamartoma. A 26 year old woman presented with a long standing painless warty lesion on her right ankle. Histological examination of the excised lesion showed a combination of two vascular lesions: superficial angiokeratoma and a deeper eccrine angiomatous hamartoma. Such a histological picture is consistent with the diagnosis of recently described eccrine angiokeratomatous hamartoma. Our case represents only second such case to be reported. Immunohistochemical analysis with CD34, smooth muscle actin and cytokeratin was done. *Corresponding author: Dr. K. Ramesh Rao, Professor and HOD, Department of Pathology, Chettinad Hospital and Research Institute, Tamilnadu 603103 INDIA Phone: +91-9884616318 E-mail: [email protected] Case Report C-160 Eccrine Angiokeratomatous Hamartoma Annals of Pathology and Laboratory Medicine, Vol. 02, No. 03, July September 2015 Introduction Eccrine angiokeratomatous hamartoma (EAKH) is a newly recognised vascular lesion of the skin, with the first case being reported only in 2006[1]. It has a distinctive histology with features derived from two well established vascular lesions affecting the skin: solitary angiokeratoma (SAK) and eccrine angiomatous hamartoma (EAH). Solitary or multiple angiokeratoma is a very common condition that presents as a single or many papular lesions on the extremities of young adults [2]. EAH is relatively rare lesion that is usually present at birth or manifests early in the childhood as multiple nodules or as a single large plaque on the extremities [3]. Since its recognition, no other case of eccrine angiokeratomatous hamartoma has been documented until now. We are reporting second such case. Case Report A 26 year-old woman presented with a painless, fleshcoloured warty lesion over the lateral malleolus of her right ankle. She had no history of trauma or surgery in the recent past and nor did she suffer from any other major illness. The patient first noticed this lesion when she was 4 years old, when it apparently started as a tiny painless nodule. Since then, it had grown very gradually to its present size of 3 cm. On several occasions in the past, it ulcerated following trivial trauma and was accompanied by pain, tenderness and crusting. No one else among her immediate family had similar lesion. The lesion was surgically excised and was submitted for hisopathological examination. The excised specimen consisted of a thick elliptical piece of skin with subcutaneous tissue. It measured 3.5x2x2 cm. The skin was verrucous. On bisection, the cut surface was fairly homogeneous tanwhite, but no clearly demarcated lesion was seen. Entire specimen was processed for hisopathological examination. Besides the routine haematoxylin and eosin (H&E) staining, the sections were also subjected to immunohistochemistry with antibodies against CD 34, cytokeratin, desmin and smooth muscle actin-a (SMA-a) [Novocastra (Leica) Mouse monoclonal antibodies]. On microscopic examination, the epidermis showed verrucous hyperplasia. But the histology was dominated by a poorly delineated vascular lesion with two distinctive morphological areas: The superficial part, which involved papillary and superficial reticular dermis, was composed of thin walled, partly ectatic capillary vessels, which at places were partly enclosed within an epidermal collarette. Some of the larger vessels were occluded by fresh intraluminal fibrin thrombi. This portion had the features of solitary angiokeratoma The deeper portion had a distinctive lobular configuration and affected the mid and deep reticular dermis. It was composed of fairly uniform thick walled capillaries intricately admixed with sweat ducts and glands. Some of the lobules contained adipose tissue with myxoid interstitium. Some of the deeper vessels showed intraluminal fibrin thrombi. This part had the histological features of eccrine angiomatous hamartoma. Immunohistochemically, the proliferating blood vessels in both areas were positive for CD 34 (figure 3 A & B) and smooth muscle actin-a (figure 4 C & D). The latter was positive either as a continuous or discontinuous single layer within the walls of vessels in the angiokeratomatous area. In the deeper eccrine angiomatous hamartomatous area, it was thick, multi-layered and more abundant. Desmin was negative in all the proliferating vessels. Cytokeratin delineated the eccrine glands and ducts in the deeper part (figure 5). Fig. 1: From the superficial part of the lesion showing Angiokeratoma-like area (Haematoxylin and Eosin, 100X) Fig. 2: From the deeper part of the lesion showing Eccrine Angiomatous Hamartoma-like area (Hearmatoxylin and Eosing, 100X)