Clear Cell Tubulopapillary Renal Cell Carcinoma
Definition
- CK7 positive, CD10 and Racemase negative clear cell carcinoma with tubulopapillary patterns
Alternate/Historical Names
- Clear cell papillary and cystic renal cell carcinoma
- Clear cell papillary renal cell carcinoma
- Clear cell papillary renal cell carcinoma of end stage kidneys
- Renal angiomyoadenomatous tumor
- Sporadic renal cell carcinoma with diffuse CK7 reactivity
Diagnostic Criteria
- Most tumors exhibit mixtures of tubular, cystic and papillary patterns
- Branching tubules and anastomosing ribbons
- Lumens may contain eosinophilic secretion
- Lumens may be compressed by sclerosis
- Nuclei typically uniformly separated from base of cell by clear cytoplasm (pseudoendometrial appearance)
- Multicystic with variably sized cysts
- Frequent intracystic papillae
- Papillae ranging from coarse to fine
- No foamy macrophages or psammoma bodies
- Branching tubules and anastomosing ribbons
- All patterns lined by a single layer of cuboidal cells
- Scant eosinophilic or moderate clear cytoplasm
- Frequently subnuclear clearing
- Low grade and stage
- Fuhrman grade 1 or 2
- Over 95% pT1a
- No vascular or renal sinus invasion
- May be multifocal
- Frequent prominent partial to complete capsule
- Most cases have at least focal smooth muscle in capsule
- Occasional cases have at least focal smooth muscle in the tumor stroma
- Immunophenotype CK7 strong positive, CD10 negative to focal, Racemase negative
- Small solid foci of clear cells reminiscent of conventional clear cell renal cell carcinoma may be seen
- These may be formed by compressed aggregates of tubules
- There is no immunohistochemical or genetic evidence that they are precursors of conventional carcinoma
- May be seen in sporadic patients and in those with end stage renal disease (Tickoo)
- Relationship to clear cell renal cell carcinoma with angioleiomyomatous stroma is not clear (Kuhn; Shannon; Mai 2010)
- Reported cases are CK7+ but CD10+ also (small numbers tested)
- Three cases studied with FISH show chromosome 3 abnormalities consistent with conventional clear cell RCC (Shannon)
John P Higgins MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting: January 24, 2011
Last update: 11/11/11
