Table of Contents
Definition / general | Sites | Pathophysiology | Clinical features | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: Tsang P. Angiomyolipoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lymphnodesangiomyolipoma.html. Accessed December 21st, 2024.
Definition / general
- Benign tumor associated with renal angiomyolipoma
- Proliferation of adipose tissue, smooth muscle and thick walled vessels in variable proportions
- Rare nodal involvement of renal angiomyolipoma likely due to multicentric tumor rather than metastasis (Int J Urol 2000;7:386, Arch Pathol Lab Med 1990;114:65)
Sites
- Retroperitoneal and periaortic lymph nodes draining the involved kidney
Pathophysiology
- Clonal process, consistent with neoplasm rather than hamartoma
- Common progenitor cell differentiating into the 3 cell types (adipose tissue, smooth muscle and blood vessels) (Semin Diagn Pathol 1998;15:21)
Clinical features
- Presents as renal mass with regional lymphadenopathy
- May be associated with tuberous sclerosis
- Fat poor angiomyolipoma can mimic renal cell carcinoma with nodal metastasis on radiograph
- Indolent clinical course and slow growth
Case reports
- 17 year old girl with angiomyolipoma of the kidney with lymph node involvement mimicking renal cell carcinoma (Int Urol Nephrol 2001;33:617)
- 28 year old man with angiomyolipoma with regional lymph node involvement (Hinyokika Kiyo 2003;49:81)
- 34 year old woman with retroperitoneal angiomyolipoma with rapidly progressing intracystic hemorrhage and lymph node involvement (Hinyokika Kiyo 2003;49:611)
- 37 year old woman with renal angiomyolipoma with lymph node involvement (Chang Gung Med J 2003;26:607)
Treatment
- Observation
- Embolization of renal mass or renal conserving surgery
Microscopic (histologic) description
- Haphazard adipose tissue and smooth muscle cells radiating from thick walled blood vessels
- Ranges from sinusoidal involvement to massive replacement of nodal parenchyma
- Smooth muscle may be epithelioid or pleomorphic
- Infrequent mitoses
Positive stains
- Myoid cells: HMB45, MelanA / Mart1, smooth muscle actin, muscle specific actin
- Fat cells: S100
Molecular / cytogenetics description
- Diploid DNA, consistent with benign behavior
Differential diagnosis
- Angiolipomatous hamartoma: may be associated with Castleman disease
- Bacillary angiomatosis: vascular proliferation due to Bartonella infection
- Kaposi sarcoma: malignant spindle cell neoplasm with vascular slits
- Lymphangiomyomatosis: proliferation of lymphatics and smooth muscles