Eccrine squamous syringometaplasia mimicking a herpetic infection

Abstract

A 69‐year‐old woman with a history of hypertension and essential tremor was diagnosed with a Burkitt‐like diffuse large‐cell lymphoma. She received chemotherapy with cyclophosphamide, vincristine and adriamycin (HyperCVAD). Ten days after starting the second cycle of chemotherapy (HyperCVAD), she presented with well‐defined, intense, erythematous macules which coalesced to form a symmetric diffuse erythema located on the upper back. Later, the lesions progressed and affected the lower back and perineal areas, extending to the groin. In a few days, a gradual diminution of the erythema was seen, with subsequent development of postinflammatory gray‐brownish hyperpigmentation. On the lower back, there were also superficial erosions. Some asymptomatic, closely grouped, gray papules, vesicles, and blisters were found in the groin, resembling the typical lesions of herpetic infection (Fig. 1). Two biopsies of the groin and one of the upper back were performed, and were processed for histopathologic and microbiologic study.Closely grouped gray papules, vesicles, and blisters on the groin mimicking a herpetic infectionimageThe histopathologic study showed epidermal hyperplasia with acanthosis and papillomatosis. In both biopsies, eccrine ducts covered by mature squamous epithelium were found in the reticular dermis (Fig. 2a−c). In the sample from the groin, an intracorneal bulla was found. Numerous normal isolated cornified cells were seen within the lumen of the bulla (Fig. 2d). An inflammatory mononuclear infiltrate was also present in a periductal and perivascular distribution. No multinucleation, ground‐glass nuclei, or peripheral margination of chromatin were found. Therefore, no morphologic evidence of herpes virus infection was present.Low (a), medium (b), and high (c) magnification showing epidermal hyperplasia and squamous syringometaplasia involving dermal eccrine ducts. (d) Medium power magnification of the intracorneal bulla (hematoxylin and eosin staining; a, ×40; b, ×100; c, ×400; d, ×100)imageCultures and serologic analyses for herpes simplex virus (HSV) 1 and 2, varicella zoster virus (VZV), and cytomegalovirus (CMV) were negative. The lesions were treated with topical corticosteroids, with a good response in a few days.