Renal Flashcards
Cystic nephroma
- multilocular cyst with a background of ovarian-type stroma: fairly blue, cellular, spindly, and estrogen and progesterone receptor positive
simple cyst
- a dilated tubule and will have a low cuboidal or flattened pink epithelial lining
multilocular cystic renal neoplasm of low malignant potential
- renal neoplasm of low malignant potential. The cyst lining and fibrovascular septa (arrowhead) are composed of clear cells with small dark nuclei (arrow)
multilocular cystic renal neoplasm of low malignant potential
Angiomyolipoma Features
- Large, tangled, tortuous, thick-walled, hyalinized vessels
- Smooth muscle cells (pink to clear and spindly) that seem to spin off of, or be continuous with, the vessel walls
- Mature fat cells without atypia or lipoblasts
- Pushing borders but not encapsulated HMB-45 and Melan-A positive (NOT S100)
Angiomyolipoma. This example does not show the fatty component, but the prominent vessels (V) and smooth muscle components here are classic. In angiomyolipoma, the spindle cells seem to merge with, or spin off from, the thick-walled vessels (arrow).
Angiomyolipoma
Angiomyolipoma
Angiomyolipoma
Angiomyolipoma
Mixed Epithelial and Stromal Tumor (MEST) Features
a population of cytologically benign tubules of varying shapes and sizes set in a background of bland spindled stroma, which may consist of smooth muscle, fibroblasts, or myofibroblasts.
MEST
Clear Cell Renal Cell Carcinoma Features
- A netlike array of delicate capillaries, dividing cells into packets (“acinar” pattern)
- Clear cytoplasm, at least focally if not diffusely
- Delicate, distinct cell membranes
- Lack of desmoplasia (although sclerosis of burned-out tumor is common)
ISUP nucleolar grade I-IV
- Grade I: nuclei resemble lymphocytes, no nucleoli
- Grade II: nuclei still small, +/− tiny nucleoli, but with open chromatin
- Grade III: easily recognizable nucleoli, larger nuclei
- Grade IV: pleomorphic and hyperchromatic nuclei with big nucleoli
Clear cell renal cell carcinoma. The tumor is composed of packets of clear cells, divided by delicate fibrovascular septa (arrow). These septa are characteristic of renal cell carcinoma and are seen even in high-grade or metastatic tumors. The nuclei in this example are enlarged, but nucleoli are visible only at high power, consistent with ISUP grade II.
Chromophobe Renal Cell Carcinoma Features
- Distinct cell membranes that give the tumor a three-dimensional texture, like alligator skin or plant cells
- Cells of varying sizes and shapes
- Pink, granular, wispy cytoplasm, often with a perinuclear clearing
- Nuclei that vary in size and shape and are crinkly, like koilocytes
- Can transform to sarcomatoid morphology
Clear Cell Papillary (or Tubulopapillary) Renal Cell Carcinoma Features
- Clear cells with small, dense, dark nuclei, often oriented with the nucleus on the luminal surface, and the cytoplasm toward the base (“upside down”
- Cells are arranged on delicate fibrovascular cores or in small closely packed tubules.
- May show cystic degeneration.
- Small tumors, well circumscribed, and often encapsulated.
Chromophobe renal cell carcinoma. (a) Low power view of chromophobe, showing packets of cells with clear-to-pink cytoplasm, perinuclear halos, and occasional binucleate cells (arrow). The cell membranes are distinct, giving the tumor a cobblestone or alligator skin texture. (b) High power view of a chromophobe carcinoma, eosinophilic variant. Although the granular pink cytoplasm resembles an oncocytoma (see Figure 13.12), the nuclei are distinctly koilocytic, with crinkly outlines and perinuclear halos (arrow). In addition, the fine cellular membranes are preserved (arrowhead).
Clear cell papillary renal cell carcinoma. There are clear cells arranged on fibrovascular cores, creating a papillary pattern. The small dark nuclei are classically lined up at the luminal surface of the clear cells, rather than at the base (arrows).
Mucinous tubular and spindle cell carcinoma. In an overall pale tumor, the nuclei are small and euchromatic and arranged in long tubules and areas of spindling.
Mucinous Tubular and Spindle Cell Carcinoma Features
- Long arrays of narrow tubules, which may remind you of renal medulla at low power
- Clear cells with indistinct cell boundaries that may fuse into spindle cell areas.
- Nuclei are small, round, and pale, sometimes with pinpoint nucleoli.
Xp11 translocation RCC
Typically a tumor with plump clear cells, large nuclei, papillary architecture, and psammoma bodies.
t(6;11) RCC
The unique feature of this tumor is a dual cell population, with nests of large clear or granular pink cells interspersed with aggregates of small compact cells which can be mistaken for lymphocytes at low power
