Angiomyomatous Hamartoma of the Inguinal Lymph Node: A Benign Masquerader of Malignancy

Document Type

Conference Proceeding

Publication Date

11-12-2025

Publication Title

Am J Clin Pathol

Keywords

CD3 antigen, adult, angiomyolipoma, case report, clinical article, conference abstract, controlled study, diagnosis, diagnostic error, differential diagnosis, endothelium cell, excisional biopsy, female, flow cytometry, hamartoma, histology, human, human tissue, immunohistochemistry, inguinal lymph node, inguinal region, Kaposi sarcoma, lymphadenopathy, menstruation, middle aged, overtreatment, T lymphocyte, vascular tumor

Abstract

Introduction/Objective: Angiomyomatous hamartoma (AMH) is a rare benign lesion involving lymph nodes, most commonly in the inguinal region. Characterized by vascular and smooth muscle proliferation, AMH may clinically and histologically mimic malignancy, leading to diagnostic confusion. Recognition of this entity is essential to avoid overtreatment. Methods/Case Report: A 31-year-old woman presented with persistent, tender right inguinal lymphadenopathy, worsening during menstruation. Excisional biopsy revealed near-total effacement of nodal architecture, replaced by a proliferation of thick- and thin-walled vessels, disorganized smooth muscle fibers within sclerotic stroma, and focal adipose tissue. Immunohistochemistry showed CD31 and partial CD34 positivity in endothelial cells, and strong smooth muscle actin (SMA) expression. HMB45 was negative, ruling out angiomyolipoma. CD3/CD20 stains confirmed residual lymphoid populations, and flow cytometry showed no evidence of lymphoma or T-cell neoplasia. Results: N/A Conclusion: AMH is an underrecognized, benign entity that may mimic malignancy clinically and pathologically. Accurate histologic and immunophenotypic assessment is essential to distinguish it from vascular tumors, lymphoma, or Kaposi sarcoma. This case emphasizes the importance of including AMH in the differential diagnosis of chronic lymphadenopathy and highlights the critical role of pathology in preventing misdiagnosis and unnecessary treatment.

Volume

164

First Page

S94

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