Immunoreactivity of Wilms tumor 1 (WT1) as an additional evidence supporting hemangiomatous rather than inflammatory origin in the etiopathogenesis of angiolymphoid hyperplasia with eosinophilia

Abstract

BackgroundAngiolymphoid hyperplasia with eosinophilia (ALHE) is a rare vascular proliferative disorder mainly located in the periauricular region. The etiopathogenesis of ALHE is unknown, and it is still controversial as to whether the entity represents a benign vascular neoplasm or an inflammatory process.AimRecently, the intracytoplasmic staining pattern of Wilms tumor 1 (WT1) on immunohistochemistry has highlighted true vascular neoplasms, such as microvenular hemangioma, tufted angioma, and spindle cell hemangioma, which has made it helpful to distinguish ALHE from vascular malformations, as there is a negative staining pattern in the other entities. We aimed to investigate the immunoreactivity of ALHE specimens for WT1 as well as glucose transporter protein 1 (GLUT1) immunohistochemistry, an important and sensitive marker for the diagnosis of infantile hemangioma, which recently has been described to label other hemangiomas, such as verrucous hemangioma.Material and methodsClinical data and histopathological specimens from patients diagnosed with ALHE were reviewed, and immunohistochemical staining and microscopic analysis for WT-1 and GLUT1 were performed.ResultsIntracytoplasmic endothelial staining of WT1 was detected in 19 of 20 ALHE specimens. GLUT1 was not detected in any ALHE specimen.ConclusionsWe conclude that ALHE may represent a true hemangioma (i.e., benign vascular neoplasia) characterized by an eosinophil- and lymphocyte-rich inflammatory component as opposed to the reactive inflammatory dermatosis with a positive intracytoplasmic staining pattern for WT1. As far as we are aware, WT1 staining for ALHE has not been described to date.

A retrospective study: Clinicopathological and immunohistochemical analysis of 54 cases of tufted angioma

“…11 The intracytoplasmic staining pattern of Wilms tumor 1 indicating vascular neoplasm is positive in tufted angioma. 13 Wilms tumor 1 has been recognized as an ideal marker for differential diagnosis between vascular neoplasms and vascular malformations. 14,15 In our series, the proliferated vessels were diffusely positive for CD31 and Wilms tumor 1, which confirms the conclusion that tufted angioma is a vascular proliferation rather than vascular malformation.…”

Absence of human polyomaviruses in angiolymphoid hyperplasia with eosinophilia in the United States

“…Angiolymphoid hyperplasia with eosinophilia (ALHE) is an uncommon eruption of papules or nodules in the head and neck region. The pathogenesis of the benign vascular proliferation that characterizes ALHE is unclear, and both a neoplastic and a reactive pathogenesis have been proposed 1–3 . Several human polyomaviruses (HPyV), including HPyV6, HPyV7, trichodysplasia spinulosa polyomavirus, and Merkel cell polyomavirus contribute to specific skin diseases, 4–6 but these viruses can also be detected on healthy skin 7 .…”

“…The pathogenesis of the benign vascular proliferation that characterizes ALHE is unclear, and both a neoplastic and a reactive pathogenesis have been proposed. [1][2][3] Several human polyomaviruses (HPyV), including HPyV6, HPyV7, trichodysplasia spinulosa polyomavirus, and Merkel cell polyomavirus contribute to specific skin diseases, 4-6 but these viruses can also be detected on healthy skin. 7 HPyV6 was detected in the lymph node of a patient with Kimura disease (KD), 8 a lymphoid and vascular proliferative disease, which was previously thought to be related to ALHE.…”