Angiomyomatous Hamartoma (AMH) of the Lymph Node; a Rare Cause for Isolated Lymphadenopath

Abstract

Introduction Angiomyomatous hamartoma is a benign vascular lesion of lymph node with unknown etiology. May represent previous inflammatory process or chronic blockade of lymphatic flow. It is characterized by replacement of the lymph node by the smooth muscle cells, varying caliber blood vessels and fibrous tissue. It commonly involves the inguinal and femoral lymph nodes and usually solitary. It is asymptomatic and rarely cause lymph edema of the lymph node. Only a few cases have been reported in the literature. Case report A 31 year old male presented with gradually enlarging right inguinal mass for three months duration. It was a gradually enlarging lump. He had no other lymph adenopathy or associated symptoms. Excision biopsy was done. The mass was firm to hard in consistency and measured 30x25x10 mm. The cut surface was homogenously whitish. Microscopy revealed a lymph node with altered architecture. The lymph node parenchyma was replaced by fibrous tissue and there were varying caliber blood vessels and proliferated smooth muscle bundles. Residual lymphoid follicles were noted at the periphery of the cortex. The lymph node capsule was thickened and no subcapsular or medullary sinuses were seen. There were no atypical cells or mitoses. Discussion Differential diagnoses for AMH include angiomyolipoma and vascular transformation of lymph node sinuses. AMH shows positivity for SMA and desmin in smooth muscle and CD 34 shows positivity for vascular endothelial cells. Angiomyolipoma shows positivity for HMB 45 in spindle cell component. However, these benign entities can be differentiated from careful microscopic assessment. Conclusion It is important to consider AMH when evaluating an isolated lymph adenopathy with vascular proliferation.