Practice questions answers renal neoplasms

Practice questions answers

Renal neoplasms

© Jun Wang, MD, PhD

1. A. A benign tumor with three components of thick-walled distorted vessel, muscular stroma and adipose tissue is consistent with angiomyolipoma. The muscular differentiation of the spindle cells is supported by positive reactivity to desmin, a muscular marker. Collecting duct renal cell carcinoma is a high grade tumor composed of solid cords or nests of markedly atypical epithelioid cells, with or without tubular architecture. Renal papillary adenoma is characterized by papillary growth lined by benign epithelial cells. Rhabdomyoma is characterized by skeletal muscle differentiation, but does not have vascular and adipose components. Atypical lipomatous tumour/well differentiated liposarcoma is a tumor with adipose tissue differentiation. It contains lipoblasts, but usually not thick-walled vessels and muscular components.

2. B.  Angiomyolipoma express HMB45, a melanocytic marker. CK7 is a cytokeratin commonly expressed by many types of renal cell carcinoma. P63 is positive in squamous cell carcinoma and urothelial carcinoma. TFE-3 is positive for Xp11 translocation renal cell carcinoma. WT-1 is positive in Wilms tumor.

3. C. Angiomyolipoma may be associated with tuberous sclerosis, a condition of hamartomatous growth involving multiple system. Patients usually have cardiac, neurological and/or dermatological presentations, as seen in this patient. It is associated with mutations of TSC1 or TSC2 genes. MET mutation is seen in papillary type renal cell carcinoma. PAX6 and WT-1 abnormalities are associated with WAGR syndrome/Wilms tumor. VHL mutation is seen in von Hippel-Lindau syndrome.

4. D. Well-circumscribed renal mass composed of tumor cells with eosinophilic granular cytoplasm can be oncocytoma or chromophobe type renal cell carcinoma. Lack of cytological atypia and diffuse reactivity to CK7, as well as negative colloid iron stain are all consistent with oncocytoma. Adult Wilms tumor has similar triphasic histological findings as seen in pediatric tumors. Adenocarcinoma of colon is usually positive for CK20. Urothelial carcinoma of renal pelvis are composed of tumor cells with urothelial differentiation, and usually do not have granular cytoplasm.

5. A. Nuclear pleomorphism, clear cytoplasm, and fine vasculatures are highly suggestive of clear cell type renal cell carcinoma. Co-expression of both cytokeratin and vimentin is relatively specific for clear cell type renal cell carcinoma. Chromophobe type renal cell carcinoma is characterized by eosinophilic granular cytoplasm with perinuclear halo. Negative reactivity to CD56 and chromogranin is not compatible with neuroendocrine tumor. Oncocytoma has eosinophilic granular cytoplasm, but lack nuclear pleomorphism, perinuclear halo, and are negative for colloidal iron stain. Urothelial carcinoma of renal pelvis are composed of tumor cells with urothelial differentiation, and usually do not have clear cytoplasm and fine vasculatures.

6. D. This patient has history of pancreas neuroendocrine tumor. With current finding of clear cell type renal cell carcinoma, she likely has von Hippel-Lindau syndrome, a condition associated with VHL mutation. MET mutation is seen in papillary type renal cell carcinoma. PAX6 and WT-1 abnormalities are associated with WAGR syndrome/Wilms tumor. TSC2 mutation is seen in tuberous sclerosis.

7. D. Clear cell type renal cell carcinoma is associated with von Hippel-Lindau syndrome. Birt-Hogg-Dubé syndrome is associated with oncocytoma or chromophobe type renal cell carcinoma. Hereditary papillary renal carcinoma is characterized by in papillary type renal cell carcinoma. Tuberous sclerosis is associated with angiomyolipoma. WAGR syndrome is characterized by Wilms tumor, aniridia, genitourinary malformations, and mental retardation.

8. C. The tumor morphology is most consistent with metastatic clear cell type renal cell carcinoma. Metastasis of renal cell carcinoma can occur ANY TIME, ANYWHERE, although the most common sites include lung and bone. Follicular adenoma of thyroid and multinodular goiter have follicular differentiation. Papillary carcinoma of thyroid has nuclear grooves and inclusions. All these three are positive for thyroiglobulin. Medullary thyroid carcinoma express calcitonin.

9. B. The most commonly seen malignant tumor of lung is metastatic malignancy. The tumor cell morphology of eosinophilic granular cytoplasm, slightly pleomorphic nuclei with perinuclear halo is highly suggestive of a metastatic chromophobe type renal cell carcinoma. With the presentation, the major problem for this patient is metastatic tumor, not infection. She has no sign of HIV infection. EGFR mutation is seen in adenocarcinoma of lung.

10. B. The tumor cell morphology of eosinophilic granular cytoplasm, slightly pleomorphic nuclei with perinuclear halo is highly suggestive of a metastatic chromophobe type renal cell carcinoma. Adenocarcinoma of lung is positive for CK7 and TTF-1. Adenocarcinoma of colon is usually positive for CK20. Squamous cell carcinoma has squamous differentiation, characterized by squamous pearls in well differentatiated tumors, and always has intercellular bridges.

11. B. The tumor cell morphology of eosinophilic granular cytoplasm, slightly pleomorphic nuclei with perinuclear halo is highly suggestive of chromophobe type renal cell carcinoma. Clear cell type renal cell carcinoma is characterized by clear cytoplasm, nuclear pleomorphism, and fine vasculatures. Adenocarcinoma of lungs can be seen kidney, but they are usually positive for CK7 and TTF-1. Oncocytoma has eosinophilic granular cytoplasm, but lack nuclear pleomorphism, perinuclear halo, and are negative for colloidal iron stain. Urothelial carcinoma of renal pelvis are composed of tumor cells with urothelial differentiation, and usually do not have granular cytoplasm.

12. A. BHD mutation is seen in oncocytoma or chromophobe type renal cell carcinoma. MET mutation is seen in papillary type renal cell carcinoma. Xp11 translocation renal cell carcinoma usually has papillary and nested growth, with eosinophilic and clear cells. PAX6 and WT-1 abnormalities are associated with WAGR syndrome/Wilms tumor. VHL mutation is seen in von Hippel-Lindau syndrome and clear cell type renal cell carcinoma.

13. D. Papillary growth with atypical cells is supportive of a papillary type renal cell carcinoma. Chromophobe type renal cell carcinoma is characterized by eosinophilic granular cytoplasm with perinuclear halo. Papillary carcinoma of thyroid has nuclear grooves and inclusions, and is positive for thyroiglobulin. Renal papillary adenoma does not have cytological atypia, and invasion. Urothelial carcinoma of renal pelvis are composed of tumor cells with urothelial differentiation.

14. B. See discussion for question 12.

15. C. High grade tumor composed of solid cords or nests of markedly atypical epithelioid cells, with or without tubular architecture is most likely of collecting duct renal cell carcinoma. Angiomyolipoma is a benign tumor with three components: thick-walled distorted vessel, muscular stroma and adipose tissue. Chromophobe type renal cell carcinoma is characterized by eosinophilic granular cytoplasm with perinuclear halo. Papillary carcinoma of thyroid has nuclear grooves and inclusions, and is positive for thyroiglobulin. Papillary type renal cell carcinoma is characterized by papillary growth covered by atypical cells, as well as clusters of foamy histiocytes and foci of calcification. Urothelial carcinoma of renal pelvis are composed of tumor cells with urothelial differentiation.

16. E. Urothelial carcinoma of renal pelvis are composed of tumor cells with urothelial differentiation, morphologically similar to squamous cells. Clear cell type renal cell carcinoma is characterized by clear cytoplasm, nuclear pleomorphism, and fine vasculatures. Collecting duct renal cell carcinoma is a high grade tumor composed of solid cords or nests of markedly atypical epithelioid cells, with or without tubular architecture. Papillary type renal cell carcinoma is characterized by papillary growth covered by atypical cells, as well as clusters of foamy histiocytes and foci of calcification.

17. A. UroVysion is useful in detecting aneuploidy of chromosomes 3, 7, 17, and loss of the 9p21 in high grade urothelial carcinoma. BHD mutation is seen in oncocytoma or chromophobe type renal cell carcinoma. MET mutation is seen in papillary type renal cell carcinoma. Xp11 translocation renal cell carcinoma usually has papillary and nested growth, with eosinophilic and clear cells. VHL mutation is seen in von Hippel-Lindau syndrome and clear cell type renal cell carcinoma.

18. E. Triphasic tumor with epithelial elements (tubular), blastemal elements (nests of undifferentiated epithelioid cells) and fibrotic stroma with positive reactivity to WT-1 is most likely Wilms tumor. Collecting duct renal cell carcinoma is a high grade tumor composed of solid cords or nests of markedly atypical epithelioid cells, with or without tubular architecture. Neuroblastoma is positive for S-100. Xp11 translocation renal cell carcinoma usually has papillary and nested growth, with eosinophilic and clear cells. Urothelial carcinoma has urothelial differentiation, morphologically similar to squamous cells. These four tumors are negative of WT-1.

19. E. WT-1 abnormalities are associated with Wilms tumor. MET mutation is seen in papillary type renal cell carcinoma. TSC2 mutation is seen in tuberous sclerosis. BHD mutation is seen in oncocytoma or chromophobe type renal cell carcinoma. VHL mutation is seen in von Hippel-Lindau syndrome and clear cell type renal cell carcinoma.

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