Eccrine Angiomatous Hamartoma: A Rare Skin Lesion with Diverse Histological Features

Abstract

Eccrine angiomatous hamartoma (EAH) is an exceedingly rare benign tumor-like lesion prevalent in childhood which may produce pain and marked sweating. The histological features include proliferation of eccrine sweat glands and angiomatous capillary channels. We report an 8-year-old girl who had a single lesion on her left lower leg. Physical examination revealed a slightly elevated, 4×7 cm erythematous plaque on the lateral aspect of left leg. Sweating in the lesion was evoked by physical work or emotional stress. There was no pain or tenderness associated with the lesion. The patient had no history of trauma to the site. These lesions were clinically angiomatous, and we obtained the diagnosis by histopathological examination. Histopathological examination of the lesion showed increased numbers of eccrine glands, as well as dilated vascular channels in the deep dermis and subcutaneous tissue. These findings are consistent with EAH.

Introduction

Eccrine angiomatous hamartoma (EAH) is a rare, benign cutaneous tumor usually present at birth or during early infancy and childhood. It may produce pain and marked sweating. We report a case of EAH occurring in an 8 year old girl.

Case Report

An 8-year-old girl presented with bruise-like, nodules noted on her left lower leg for the last 2 years. Her nodules were gradually increasing in size and now involved lateral aspect of the left ankle. She had an additional lesion on her left sole. Her lesions have increased in number and grown proportionately with the patient. There was no discharge or pain or any other symptoms on the lesion. She is otherwise developmentally normal and has no musculoskeletal abnormalities. Her past medical history was insignificant.

Physical examination revealed an irregular, nodular plaque of 4×7 cm, with an overlying ecchymotic to dark surface beginning below the left ankle joint extending down to the lateral aspect of the dorsum of foot [Figure 1]. Similar lesion was present on the sole on the same side. Nodules were of varying firmness and had no pulsations or bruits. Stroking failed to elicit muscular contraction. Sweating was comparatively more on the skin over the lesions compared to the surrounding skin. No leg length discrepancy was present and the patient had full range of motion of both lower extremities. Examination of the hair, nails and mucous membranes were unremarkable.

Figure 1.

Eccrine angiomatous hamartoma in the left leg

Histopathological examination showed a thickened epidermis and an increased number of small and medium-sized blood vessels with thin muscular walls of uneven thickness. An increased number of eccrine glands with large coils composed of an increased number of tubules and ducts with a normal proportion of cells were noted in the dermis. There was abundant fibromyxomatous stroma in these coils. The dermis appeared to have increased thickness with mature fat cells [Figures 2 and 3]. Collagen bundles were thicker and in haphazard array. Some collagen bundles were oriented perpendicular to the skin surface. The clinical and histopathological findings supported a diagnosis of multiple EAH.

Figure 2.

H and E-stained biopsy specimen (×100) showing eccrine gland hyperplasia, fat cell proliferation and small and medium blood vessel proliferation

Figure 3.

H and E-stained biopsy specimen (×100) showing eccrine gland hyperplasia, few mature fat cells and small and medium blood vessel proliferation

Discussion

EAH have been reported in both sexes. It has also been reported to occur in older age group.[1] The exact pathogenesis is not know but various theories like abnormal induction of heterotypic dependency with resultant malformation of adnexal as well as mesenchymal elements have been proposed.[2] Clinically, EAH presents as an angiomatous lesion, usually solitary, although several cases with multiple lesions have been described. EAH, generally asymptomatic, occasionally presents with pain and focal hyperhidrosis (accounting for the designation of Sudoriferous angioma adopted by some authors).[3] The hyperhidrosis is presumably an expression of its eccrine component. Hyperhydrosis may be absent in some cases.[4] They have occurred at several sites, particularly the palm and sole, but also on other parts of the feet, on the face, neck and on the trunk. Generally, they enlarge very gradually; more rapid growth has been described during pregnancy[5] and adolescence.

On histopathology, EAH is characterized by a dermal proliferation of well-differentiated eccrine secretory and ductal elements closely associated with thin-walled angiomatous channels. In addition, unusual histopathological variants have been reported and include the infiltration of adipose tissue,[6] increased dermal mucin,[7] and the presence of apocrine glands or pilar structures. Where the angiomatous element predominates, the term sudoriparous angioma has been applied. The nevus sudoriferus type of eccrine nevus may represent the non-angiomatous end of the same spectrum of hamartomas.

Clinically, this condition must be differentiated from other neonatal angiomatoses. Sometimes the clinical findings are nonspecific, whereas histological examination may exclude the other conditions. The differential diagnosis of EAH may include an eccrine nevus, tufted angioma, macular telangiectatic mastocytosis, nevus flammeus, glomus tumor and smooth muscle hamartoma.

While definitive diagnosis is based upon histology, MRI[8] and ultrasound are useful to delineate the extent of soft tissue and vascular masses. Immunohistochemical staining for S-100 and carcinoembryonic antigen (CEA), for eccrine glands and the antifactor VIII-related antigens, for vascular channels can also be done. The natural history of EAH is benign and typically slow-growing. There have been no reported complications. Although aggressive treatment is generally unwarranted, simple excision is usually curative as was done here. Recently botulinum toxin[9] and intralesional sclerosants[10] have been successfully used in the treatment of this condition. It is important to recognize this condition because it is a benign lesion for which aggressive treatment is not indicated. This case is being reported as very few cases have been reported from India.