Unusual presentation of angiomyomatous hamartoma in an eight-month-old infant: case report and literature review

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.

A rare case of angiomyomatous hamartoma in the pelvic and paraaortic lymph nodes

Angiomyomatous hamartoma (AMH) of the lymph node is an extremely rare, benign vascular disease of unknown etiology. It is characterized by partial or complete replacement of the lymph node parenchyma by irregularly distributed, thick-walled blood vessels, smooth muscle bundles and adipose tissue in a fibrotic stroma. Angiomyomatous hamartoma occurs mainly in inguinal and femoral nodal regions, but there are a few reports of some other locations - submandibular, cervical, popliteal and paraaortic lymph nodes. We present a case of a 37-old female patient with AMH in the pelvic and paraaortic lymph nodes who presented with weight loss - 7 kg in 7 months. The differential diagnosis of AMH includes lymphangiomyomatosis, which, unlike AMH, involves primarily thoracic and intra-abdominal lymph nodes: nodal leiomyomatosis with less pronounced vascular proliferation and angiomyolipoma of the lymph node. The latter is composed of the same tissues as in AMH, but the smooth muscle component shows increased cellularity, polymorphism and increased mitotic activity, as well as a typical immune profile with coexpression of melanocyte markers and estrogen, which were negative in our case. The world literature references show that this is the first reported case in which the disease manifested itself with weight loss and affected paraaortic lymph nodes in a female patient.

Intranodal Angiomyomatous Hamartoma in a Cynomolgus Monkey

We describe here an angiomyomatous hamartoma in the right axillary lymph node of a three-year-old male cynomolgus monkey ( Macaca fascicularis), used as a control subject in a short-term toxicity study. This is a very rare lesion that has been reported almost exclusively in inguinal lymph nodes, and to date only in human beings. In the present case, light microscopy revealed partial replacement of the lymph node parenchyma by a disorganized, irregular vascular network, sparsely distributed smooth muscle cells, and a fibro-adipocytic stroma. This was considered to be fortuitous given the age of the animal, with no clinical or toxicological significance. To the best of our knowledge, this is the first report of an intranodal angiomyomatous hamartoma in a nonhuman animal species.