Kindeys Flashcards
What are some renal benign and malignant neoplasms?
Benign :
• Papillary Adenoma
• Metanephric Adenoma
• Oncocytoma
• Angiomyolipoma
Malignant :
• Clear Cell RCC
• Papillary RCC
• Chromophobe RCC
• Collecting Duct Carcinoma
What is papillary adenoma?
Very frequent lesion that appears as small, benign, well circumscribed, yellow grey nodule in the renal cortex. It is very similar to papillary carcinoma, for it to be an adenoma it must have a diameter smaller than 5 mm, have a papillary architecture, resemble low grade papillary RCC but not any other RCC.
What is metanephric adenoma?
Rare tumor. Clinically it manifests polycythemia, flank pain, mass and hematuria. Morphologically it is highly cellular with small tubules lined by cuboidal epithelium. It is important as it may be confused with nephroblastoma and papillary RCC.
What is an oncocytoma?
Epithelial neoplasm composed of large eosinophilic cells with an apparently healthy appearance. It arises from the intercalated cells of collecting ducts. Macroscopically it is a circumscribed brown mass with a solid or nested growth pattern. It can get very big up to 12 cm. Differential diagnosis to eosinophilic variant of chromophobe RCC.
What is an angiomyolipoma?
Peculiar tumor made of fat, smooth muscles and blood vessels. Present in 25 to 50% of patients with tuberous sclerosis. Biopsy shows all three types of tissues.
What is renal cell carcinoma?
2% of all cancers. Most common renal malignant neoplasm. RCC is mostly a cancer of adults and males. Risk factors are smoking, obesity, hypertension, exposure to asbestos and heavy metals. Most of the cases are sporadic but about 4% are familial and are linked to other genetic disease like : Von Hippel Lindau Disease (VHL), Tuberous Sclerosis
Clinically patient present costovertebral pain, palpable mass, hematuria and other more systemic symptoms like fever, weakness and weight loss. Less commonly there may be endocrine effects like hypercalcemia, hypertension, hepatic dysfunction and amyloidosis. RCC has the tendency to metastasize even before local symptoms, 25% of cases have metastasis at the time of presentation to the lungs and bone.
What is clear cell RCC?
Most common type of RCC accounting for 70 to 80% of cases. Characterized by clear of granular cytoplasm and the cells are non papillary. It is mostly sporadic but patients have the VHL gene (98%). Fuhrman Nuclear grading system is used. It is important to understand differential diagnoses as it is a common site of metastasis.
What is papillary RCC?
Second most common RCC. Less malignant than other RCC but can still metastasize. It is important to distinguish it from clear cell RCC as papillary RCC is not treated with immunotherapy. Macroscopically it is pale brown, circumscribed, often multifocal and bilateral. High nuclear to cytoplasm ratio, psammoma bodies and foamy macrophages.
What is Chromophobe RCC?
Less common. Better prognosis. It arises from intercalated cell of collecting duct to so it is import to distinguish it from oncocytoma, it staines Hale’s colloidal iron stain. Grossly it can appear like other tumors. Histologically it shows a very thick cytological membrane.
What is collecting duct carcinoma?
Most rare of the RCCs, represents 1%. Originates from collecting duct cells in the medulla and it is highly aggressive. Easily recognizes as it is a dense white grey lesion with infiltrative borders, necrosis. It shows an irregular tubular and glandular architecture. Typical finding is Hobnail cells which are peculiar cells with nuclear projections.
What is Von Hippel Lindau Disease (VHL)?
It is an autosomal dominant disorder characterized by a constellation of lesions in various organs. VHL protein is a tumor suppressor gene which when activated degrades HIF1a a TF that induces angiogenesis factors. Therefore due to inactivation there will be higher levels of HIF1a resulting in proliferating cells and enhancement of angiogenesis.
