Angiomyomatous hamartoma of lymph nodes, revisited: clinicopathologic study of 21 cases, emphasizing its distinction from lymphangioleiomyomatosis of lymph nodes

Multinodal Cervical Angiomyomatous Hamartoma

Angiomyomatous hamartoma (AMH) is a rare benign lesion of the lymph nodes. Angiomyomatous hamartoma tends to be found in inguinal lymph nodes, and usually in a single lymph node. We present a rare care case of a 53-year-old presenting with a neck lump, found to be AMH involving multiple lymph nodes in her neck. To our knowledge, this is the first case presenting with multiple nodes in this location. There are a limited number of case reports describing magnetic resonance imaging (MRI) features of AMH lesions located in inguinal and head and neck regions. Our MRI findings revealed the mass had intermediate T1 enhancement, high T2 signal enhancement, and high post-gadolinium enhancement and fat saturation of the lesion. Angiomyomatous hamartoma is a histological diagnosis, distinguished from other similar nodal vascular lesions by a number of key features: including the presence of central nodal distribution, muscular blood vessel walls, adipose tissue, and HMB45 negative staining. Early recognition of this benign lesion may have implications for a patient's clinical course and surgical requirements.

Triple whammy: a rare case of epithelioid hemangioendothelioma with synchronous angiomyomatous hamartoma complicated by Actinomyces meyeri

Epithelioid hemangioendothelioma is a rare vascular malignancy that originates from vascular endothelial or pre-endothelial cells and is composed of epithelioid or histiocytoid cells. This malignancy has an incidence of approximately one per one million individuals and can occur in various regions of the body including the lungs, liver, bones, and soft tissues. The behavior of this cancer can range from indolent to aggressive and diagnosis and treatment are often delayed due to variable presentations and lack of established treatment guidelines. Here we present the case of a 27-year-old Hispanic male that presented with right groin pain, abdominal pain, and a fifty-pound weight loss over one year. The patient had a complex hospital course during which he was found to have an angiomyomatous hamartoma of his right groin area, postsurgical right inguinal wound infection with Actinomyces meyeri, and epithelioid hemangioendothelioma distal to the right iliac bifurcation. The patient is currently pending further imaging studies to evaluate candidacy for surgical resection and following with oncology for chemotherapeutic options.

An Angiomyomatous Hamartoma With Features of Vascular Transformation of Sinuses in the Mediastinal Lymph Node of a Beagle Dog

Two similar benign, nonneoplastic vascular lesions have been described in the lymph nodes of humans and animals: angiomyomatous hamartoma (AMH), which is characterized by the replacement of lymphoid tissue by blood vessels, smooth muscle, and fibrous tissue, and vascular transformation of sinuses (VTS), which is considered a reactive transformation of lymph node sinuses into capillary-like vascular channels. We hereby report a lesion with features common to both lesions in the mediastinal lymph nodes of a 1-year-old beagle dog in a 1-month toxicity study. Grossly, enlargement and red discoloration were observed, while microscopically, the lesion was characterized by effacement of the lymph node parenchyma with replacement by mature blood vessels, smooth muscle, and fibrous tissue, associated with lymphoid atrophy, which is consistent with AMH. However, multifocal areas of anastomosing or plexiform capillary-like channels lined by normal to slightly plump endothelium, similar to those described for VTS, were also present. Immunohistochemistry analysis revealed abundant positive staining for smooth muscle actin and endothelial cells (von Willebrand factor/factor VIII) and the absence of proliferation (Ki67). In conclusion, these lesions most likely represent a mixture of both AMH and VTS.