Angiomyomatous Hamartoma of Popliteal Lymph Node: An Unusual Entity

Angiomyomatous hamartoma in a postauricular lymph node: A rare entity masquerading as a cyst

“…Relevant histologic differential diagnoses include leiomyomatosis, angiomyolipoma of the LN, and LAM, all of which affect the deep nodes of the abdomen and pelvis. 2 , 8 , 9 In comparison with AMH of LN, nodal leiomyomatosis lacks a significant vascular component. 9 AMH of LN may be distinguished from angiomyolipoma of the retroperitoneal LNs with the use of immunohistochemistry, as the latter is human melanoma black-45 positive and is also associated with multifocal angiomyolipoma of the kidney.…”

“…AMH of LN does not stain with these markers. 2 , 9 Interestingly, variations of LAM can lack a key characteristic of obvious lymphatic channels and may present as benign fascicular spindle proliferations that highly resemble AMH without immunohistochemical staining. 1 This raises the question of whether earlier diagnoses of AMH predating such immunologic stains may have actually been variants of the aforementioned pathologies.…”

“…Histologically, it is characterized by the replacement of nodal architecture with blood vessels, smooth muscle cells, and variable amounts of fibrous and adipose tissue in a collagenous stroma. 1 , 2 First described in 1992, there are now 30 cases reported in the literature, primarily involving the inguinal and femoral LNs; rarely, cervical and submandibular nodal involvement have been described. 1 , 3 , 4 , 5 , 6 , 7 Herein we present the first case, to our knowledge, of AMH arising within a postauricular node and clinically masquerading as an epidermal inclusion cyst.…”

Intranodal Angiomyomatous Hamartoma in a Cynomolgus Monkey

“…Clinically, AMH is often characterized by lymphadenomegaly, lymphedema, draining limb enlargement, and previous nodal inflammation (Mridha et al 2015). The present case was not associated with clinical findings, and the enlarged node was not noticed until necropsy.…”

“…Primary vascular lesions of the lymph node are uncommon and range from benign conditions (e.g., intranodal hemangiomas and angiomyomatous hamartomas [AMHs]) to malignant neoplasms (e.g., Kaposi’s sarcoma and hemangioendothelioma). Since its first description (Chan et al 1992), only 31 cases of AMH have been reported, all of which were in humans (Dzombeta et al 2012; Mridha et al 2015; Lee, Chang, and Ku 2015).…”