Epithelioid hemangioma (angiolymphoid hyperplasia with eosinophilia) in zosteriform distribution.

Epithelioid hemangioma (EH) or angiolymphoid hyperplasia with eosinophilia (ALHE) is an uncommon benign disease. We report an unusual case of EH (ALHE) that arose on the lower back in a zosteriform array. The presence of the characteristic histological appearance of plump endothelial cells with hobnail-like protrusions led to the diagnosis of EH (ALHE). Histological examination of the lesion also revealed the existence of arteriovenous shunts, the possible factor contributing to the pathogenesis of EH (ALHE).

Introduction

Epithelioid hemangioma (EH) was described originally in 1969 as angiolymphoid hyperplasia with eosinophilia (ALHE).[1] Lesions usually present as single or multiple red-brown papules or subcutaneous nodules with a predilection for the head and neck region. Involvement of the trunk is extremely rare and only nine cases of EH (ALHE) outside the head and neck region has been reported in the literature as of 2001.[2] We report an unusual case of EH (ALHE) that arose on the lower back in a zosteriform array.

Case Report

A 38-year-old male presented in September 2009 with asymptomatic brown papules and nodules on the lower back. He had initially noticed these lesions 3 years earlier and they had gradually extend around the primary lesions on the back. Physical examination revealed brown papules and nodules on the left side of the lower back, distributed in a zosteriform array [Figure 1]. The patient denied past history of herpes zoster, injury, topical application of any sort, or insect bite at this site. Surgery for a herniated intervertebral disc had been performed several years before.

Figure 1

Brown papules and nodules on the lower back

Laboratory findings revealed no evident eosinophilia or elevation of immunoglobulin E levels. Skin biopsy revealed elongation of rete ridges, basal hyperpigmentation, a lymphocytic infiltrate with occasional eosinophils [Figure 2], and the presence of thick-walled vessels adjacent to venules in the lower portion of the dermis [Figure 3]. The vascular channels were lined by enlarged plump endothelial cells with an ‘epithelioid’ appearance and cytoplasmic vacuolation [Figure 4]. Immunohistochemical staining revealed that the enlarged endothelial cells were positive for CD31, CD34, and factor VIII. The existence of the underlying arteriovenous shunt or hemangioma had not been identified on the follow-up MRI done after his surgery for herniated intervertebral disk. Diagnosis of EH (ALHE) was made based on the histological findings. Treatment with topical steroid application for 1 year was not effective.

Figure 2

Lymphocytic infiltrate with a few eosinophils around the vessels (hematoxylin and eosin; ×200)

Figure 3

Thick-walled vessels adjacent to venules in the lower portion of the dermis (hematoxylin and eosin; ×40)

Figure 4

Vascular channels lined by plump endothelial cells with vacuolation and hobnail-like protrusions (hematoxylin and eosin; ×100)

Discussion

ALHE is believed to be the most appropriate denotation because it is not confusing, is well established in the literature, and is a histopathologically adequate description.[34] In this case, since the eosinophilic infiltration was too mild to diagnose definite ALHE, we prefer to use the term EH based on the histological findings—especially the protrusion of endothelial cells. Furthermore, EH better describes the possible neoplastic nature of the entity.[5]

The differential diagnosis of EH (ALHE) includes other vascular tumors and tumor-like conditions of blood vessels, such as angiosarcoma, cutaneous epithelioid angiomatous nodule, bacillary angiomatosis, and epithelioid hemangioendothelioma.

In our case, angiosarcoma was ruled out by the absence of conspicuous cytologic atypia, frequent mitotic figures, or piling up of cells.[6] Unlike cutaneous epithelioid angiomatous nodule, the lesions were not composed of solid sheets of epithelioid endothelial cells.[6] The absence of bacilli, acute neutrophilic inflammation, and capillary proliferation typical of pyogenic granuloma ruled out bacillary angiomatosis.[6] Distinction from epithelioid hemangioendothelioma was made by the lesion's architecture and the presence of prominent inflammation and numerous well-formed blood vessels, with a lack of extravascular proliferation of epithelioid neoplastic cells.[6]

There is no consistently effective treatment for this disease and several therapeutic modalities, including intralesional and systemic corticosteroid, has been used with limited success.[7] The lesion can be managed by surgery but recurrences are common unless the arteriovenous shunt is also excised.[3] We did not perform any active treatment (i.e., either systemic corticosteroid administration or excision) because the patient lacked any disabling symptoms and he did not prefer such treatment.

Although the pathogenesis of ALHE is not fully understood, previous reports have suggested the involvement of arteriovenous shunts; these shunts are made up of clustered, thick-walled vessels adjacent to or communicating with venules or capillaries.[8] In the present case, the existence of the arteriovenous shunt was identified histologically. However, the imaging study did not reveal the vascular lesion.

Zosteriform EH (ALHE) is an uncommon manifestation.[9] In our case, the ‘epithelioid’ cells in the lesion showed the typical immunophenotype of endothelial cells. Although an obvious arteriovenous shunt was not identified beneath the lesion in the imaging study, the distribution of the lesion in this case was consistent with the area served by the histological aberrant vessels, the possible pathogenesis of EH (ALHE).