Renal Angiomyolipoma: A Diagnostic and Therapeutic Challenge.

BACKGROUND: Angiomyolipomas (AML) represent less than 10% of renal tumours. They are most often detected incidentally during imaging tests, but there are several histological variants that pose difficulties in the radiological differential diagnosis. Their identification should allow the loss of renal parenchyma due to embolization or radical surgery to be prevented. METHODS: Retrospective study of patients undergoing kidney surgery with post-surgical pathological diagnosis of AML at the Álvaro Cunqueiro Hospital (2016-2021). Patients with a radiological diagnosis of AML who underwent surgery based on clinical criteria were excluded. RESULTS: 18 patients were registered, allowing for the assessment of 18 renal tumours. All of the cases were diagnosed incidentally. Preoperative radiological diagnosis was: 9 lesions suggestive of renal cell carcinoma (RCC) (50%), 7 cases suggestive of RCC vs. AML (38.9%) and 2 lesions suggestive of AML vs. retroperitoneal liposarcoma (11.1%). Histological variants of AML were found in 61.1% of cases (n = 11). The most widely used surgical technique was partial nephrectomy, in 66.67% of cases. CONCLUSIONS: The radiological differential diagnosis of AML, and particularly its variants, with malignant lesions have important limitations either due to the predominance or scarcity of any of the AML components. Some cases can also pose difficulties at the histological level. This fact highlights the importance of the specialization of uroradiologists and uropathologists and the performance of kidney-sparing therapeutic techniques.

SATB2 as a Marker of the Proximal Nephron: Expression in Nephrogenic Adenoma and Correlation With Other Renal Tubular Markers.

Nephrogenic adenoma (NA) is an infrequent reactive urothelial lesion. The expression of immunohistochemical renal tubular markers has been reported in NA, although a proximal or distal nephron phenotype has not been established. Special AT-rich sequence-binding protein 2 (SATB2) is a marker of a colorectal origin of adenocarcinomas, occasionally reported in renal samples. We have analyzed SATB2 expression in NA, with correlation with other tubular markers, as well as in the normal kidney. Fifty cases of NA were immunostained with PAX8, SATB2, proximal nephron markers [CD10, renal cell carcinoma (RCC) marker, alpha-methylacyl-CoA racemase (AMACR), and CD15], and distal markers (Ksp cadherin, cytokeratin 7, E-cadherin (E-cad), and cytokeratin 19). Ten normal kidney sections were stained with a double method combining SATB2 plus CD10, RCC marker, AMACR, Ksp cadherin, cytokeratin 7, or E-cad. All NA were immunoreactive for PAX8 and 57% for SATB2. Every case was positive for proximal and distal nephron markers: 100% for cytokeratins 7 and 19, 84.1% E-cad +, 81.6% AMACR +, 68.9% Ksp cadherin +, 63% CD15 +, 53.3% CD10 +, and 28.6 % RCC +. In the normal kidney, SATB2 was detected in the straight part of the proximal tubules and the thin descending loops of Henle. NA shows a multiphenotypic pattern with coexpression of both proximal and distal nephron markers, and constant expression of PAX8, cytokeratins 7 and 19. SATB2 is often positive in NA, which should be kept in mind to avoid a possible misdiagnosis of intestinal adenocarcinoma. SATB2 is a marker of the normal proximal nephron.

Intraductal Carcinoma of the Prostate without High-Grade Invasive Adenocarcinoma: Report of Two Cases and Review of the Literature.

OBJECTIVES: Intraductal carcinoma of the prostate (IDC-P) is usually associated with high grade, aggresive acinar adenocarcinomas. IDC-P is supposed to result from the spread of the adenocarcinoma along the prostatic ducts. IDC-P rarely occurs without invasive carcinoma or with a coexistent low grade adenocarcinoma. MATERIAL AND METHODS: We report two patients, 66 and 75 year-old, who presented IDC-P and low-grade acinar adenocarcinoma foci in their radical prostatectomy surgical specimens. RESULTS: Acinar adenocarcinomas were grade group 1, PTEN+, pT2. In the first case, the invasive adenocarcinoma was adjacent but nor intermingled with the IDC-P, and a discordance in the immunophenotype between them was outstanding (positivity for ERG in the acinar carcinoma being negative in the IDC-P). In the second case, the foci of adenocarcinoma were distant from the IDC-P. The first patient had not biochemical recurrence after a 34 month follow-up period. CONCLUSIONS: This kind of cases supports the existence of an infrequent subtype of IDC-P that could be considered as an in situ neoplasia.