renal papillary adenoma

Ten-year
follow-up of renal adenomatosis with magnetic resonance imaging: a case report. Abdominal MRI with contrast enhancement performed in January 2010. a On axial fat-saturated T2-weighted images, papillary adenomas present as well-defined hypointense nodules (arrow and arrowhead) in the bilateral renal parenchyma. b, c Papillary adenomas present high signal intensity (arrow and arrowhead) on axial diffusion-weighted (b-value: 800) images and low signal intensity (arrow and arrowhead) on the corresponding apparent diffusion coefficient maps, suggesting diffusion restriction. d, e, f On axial dynamic contrast-enhanced T1-weighted images with fat suppression, papillary adenomas present isointensity in the renal parenchyma on unenhanced images and relatively poor contrast enhancement in the arterial and venous phases (arrow and arrowhead)
jmedicalcasereports.biomedcentral.com • CC-by-4.0
Ten-year
follow-up of renal adenomatosis with magnetic resonance imaging: a case report. Abdominal MRI performed in August 2020. a On axial T2-weighted images, multiple papillary adenomas were observed in the renal cortices of the bilateral kidneys (arrow and arrowhead). Progression of the tumors was evident based on the increased tumor size and tumor number. b, c On axial diffusion-weighted images and apparent diffusion coefficient maps, more renal adenomas were noted in the bilateral kidneys with diffusion restriction (arrow and arrowhead). The imaging features remained consistent with those seen 10 years earlier. d, e, f On axial dynamic contrast-enhanced T1-weighted images with fat suppression, papillary adenomas present isointensity relative to the renal parenchyma on unenhanced images and relatively poor contrast enhancement in the arterial and venous phases (arrow and arrowhead). These imaging characteristics remained consistent with those seen 10 years earlier
jmedicalcasereports.biomedcentral.com • CC-by-4.0
Ten-year
follow-up of renal adenomatosis with magnetic resonance imaging: a case report. Iodine-enhanced CT images acquired in October 2018. a On unenhanced CT images, a slightly hyperdense and exophytic-growing nodule was observed (pathological analysis showed epithelioid angiomyolipoma) at the posterior aspect of the right kidney. b In arterial-phase CT images, the epithelioid angiomyolipoma was significantly enhanced. In addition, there were multiple small renal nodules (pathological analysis showed papillary adenomas) with poor enhancement in the bilateral kidneys. c, d On nephrographic and excretory-phase computed tomography images, the epithelioid angiomyolipoma (black arrow) was hypodense relative to the adjacent renal cortex. The papillary adenomas were iso- to hypodense in the renal cortex in the excretory phase
jmedicalcasereports.biomedcentral.com • CC-by-4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Papillary adenomas of the kidney are benign renal neoplasms arising from the renal tubular epithelium and almost always located within the cortex. They fall under the general category of renal adenomas, and are considered one of the commonest of renal epithelial neoplasms.

Epidemiology

The estimated prevalence rate is ~40% in patients older than 70 years of age (by autopsy series).

Clinical presentation

Most papillary adenomas are asymptomatic.

Pathology

As defined in the 2016 WHO classification, papillary adenomas are unencapsulated, low grade tumors with papillary or tubular architecture, measuring ≤1.5 cm in diameter (previous guidelines defined a size cutoff of 0.5 mm).

A papillary adenoma-to-carcinoma sequence has been described that is akin to similar transformation in colonic adenomas.

Adenomas are histologically characterized by papillary or tubular cytoarchitecture and frequent psammoma bodies.

Genetics

Cytogenetic changes of papillary adenomas include loss of the Y chromosome and combined trisomy of chromosomes 7 and 17. Histologic and genetic abnormalities of renal adenomas are indistinguishable from papillary RCCs.

Associations
  • von Hippel Lindau disease
  • acquired renal cystic disease, long-term haemodialysis
    • these papillary adenomas may have different pathogenesis

Radiographic features

Papillary adenomas are usually extremely small (<15 mm) and may not be distinguished from other renal tumors (e.g. RCC/papillary renal carcinoma pRCC) and renal pseudotumors on imaging.

See also

  • renal papillary adenomatosis - multiple papillary adenomas
Siehe auch:
Assoziationen und Differentialdiagnosen zu papilläres Adenom der Nieren:
Nierenzellkarzinom
 
Wikipedia • CC BY-SA 3.0
Nierentumor
 
Wikipedia • CC BY-SA 3.0
Morbus
Hippel-Lindau
Wikipedia • CC BY 2.5
benigne
Nierentumoren
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