Intraglomerular Lesions of Renal Angiomyolipoma in Tuberous Sclerosis Complex: A Case Report

Abstract

The association between tuberous sclerosis complex (TSC) and renal angiomyolipomas (RAML) is widely recognized, but the evidence of intraglomerular microlesions of angiomyolipoma in TSC is extremely rare. We report a 36-year-old woman with TSC, presenting as gross hematuria and hypovolemic shock. The patient was diagnosed with bilateral RAML and spontaneous rupture of right RAML. She underwent right nephrectomy. Microscopic examination revealed multiple bilateral RAML composed of dysmorphic blood vessels, smooth muscle, epithelioid cells and adipose tissue, as well as intraglomerular microlesions of these components in continuity with the glomerular basement membrane but without adhesion to the Bowman's capsule. In this report we describe the histopathologic features and immunohistochemical markers of TSC-associated RAML with multiple parenquimatous lesions and isolated micro foci in the glomerular tuft. We also review recent discoveries related to possible pathogenesis of renal and intraglomerular lesions.

Cutaneous Angiomyolipoma—A Distinct Entity That Should Be Separated From Classic Angiomyolipoma: Complete Review of Existing Cases and Defining Fundamental Features

“…There are several histologic variants, including microscopic AML (absent thick-walled blood vessels) [ 104 , 105 ], intraglomerular AML (epithelioid smooth muscle cells intermixed with a few adipocytes in capillary tufts) [ 106 , 107 ], AML with epithelial cyst (cysts, “cambium-like” stromal cells, solid smooth muscle predominant areas, prominent lymphovascular network, and rare adipose tissue) [ 108 , 109 ], lymphangiomatosis of the renal sinus (plaque-like mass in the renal pelvis) [ 110 ], sclerosing AML (cords and trabeculae of bland epithelioid cells in abundant sclerotic stroma) [ 111 ], and epithelioid AML (EAML) [ 40 , 87 , 104 , 112 ]; the latter has distinct implications that require further description.…”