Table of Contents
Definition / general | Sites | Pathophysiology | Clinical features | Case reports | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Immunohistochemistry & special stains | Differential diagnosisCite this page: Tsang P. Angiomyomatous hamartoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lymphnodesangiomyomatoushamartoma.html. Accessed September 27th, 2023.
Definition / general
- First described by Chan et al. in 1992 (Am J Surg Pathol 1992;16:335)
- Rare and benign vascular disorder due to proliferation of blood vessels and smooth muscle in lymph nodes, often of long duration
Sites
- Mostly involves inguinal or femoral lymph nodes
- May have associated limb edema
- Rare reports of cervical lymph node (Histopathology 1996;29:80) and popliteal lymph node involvement (Ann Diagn Pathol 2008;12:372)
Pathophysiology
- Unknown etiology; may represent reparative reaction to previous nodal inflammation
Clinical features
- Usually males, all ages
- Benign clinical course
- Local excision is curative
- No known recurrence or metastasis
Case reports
- 8 month old infant with cervical, anterior midline mass (BMC Pediatr 2012;12:172)
- 51 year old man with inguinal lymph node lesion (Pathol Int 2000;50:655)
- 60 year old man with several year history of lower leg edema (Case of the Week #118)
- 82 year old man with inguinal mass (Rare Tumors 2009;1:e25)
- Inguinal lymph node (Gen Diagn Pathol 1997;143:247)
Gross description
- Enlarged and matted lymph nodes replaced by firm, white tissue
Microscopic (histologic) description
- Extensive and multifocal nodal involvement by thick walled hilar blood vessels, often with increased fibrous tissue
- Nodal parenchyma has haphazard smooth muscle cells in sclerotic stroma
- Starts in nodal hilum and extends toward cortex
- May have admixed adipose tissue
- No cellular pleomorphism, no necrosis, low mitotic rate
Microscopic (histologic) images
Immunohistochemistry & special stains
- Smooth muscle actin and desmin stain smooth muscle fibers
- CD34 highlights endothelial cells
- HMB45-, in contrast to angiomyolipoma of lymph node
Differential diagnosis
- Angiolipomatous hamartoma: associated with Castleman disease
- Angiomyolipoma: HMB45+, typically involves retroperitoneal nodes, associated with renal angiomyolipoma
- Lymphangiomatosis: female predominance; smooth muscle fascicles around anastomosing ectatic vascular spaces
- Vascular transformation of lymph node sinuses: small vascular channels replacing nodal sinuses