Pathology Notes

Renal medullary carcinoma Updated: 05/05/2021 © Jun Wang, MD, PhD General features Aggressive Predominantly seen in patients with sickle cell disorder More common in male, mean age 26 Loss of SMARCB1/INI1 Pathological features Markedly pleomorphic tumor cells Various pattern Back to renal cell carcinoma Back to kidney masses Back to contents

Tuberous sclerosis   Updated: 11/01/2021 © Jun Wang, MD, PhD General features Autosomal dominant syndrome De novo mutation of TSC1 or TSC2 may be seen in sporadic cases Affecting differentiation, proliferation, and migration early in development Increased risk of malignancy Clinical presentations Variety of hamartomatous lesions Commonly involve multiple organs Brain: Tubers, subependymal nodules, subependymal giant cell astrocytomas (SEGAs), may cause seizures Heart: Rhabdomyoma Skin: Ash-leaf spots , adenoma sebaceum, shagreen patch Eyes: Retinal astrocytomas Kidney: Polycystic kidney, renal cyst , renal angiomyolipoma , renal cell carcinoma Lung: Lymphangioleiomyomatosis , causing dyspnea and pneumothorax Liver: Cyst, angiomyolipomas Genetic abnormalities TSC1 TSC2 Work ups Laboratory studies: Genetic mutations Imaging studies: Tumors of brain, kidney, heart, etc Electroencephalography: If seizures are suspected Electrocardiography: Arrhy

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

Practice questions II Renal neoplasms © Jun Wang, MD, PhD 1. Use this case for next three questions . A 45-year-old man presents with left flank discomfort for 4 months. He has a history of seizure and arrhythmia since age of 8. He denies history of other health problems. He does not smoke nor drink alcohol. His father has a history of arrhythmia. His mother has type II diabetes and diabetic nephropathy. He has an irregularly irregular pulse rate at approximately 68 per minute. His vitals signs are otherwise unremarkable. No other abnormalities are noted through physical examination, except a few brown skin fibrous plaque on his face. Radiologic examinations reveal a 5.5 cm solid mass at his left kidney. His right kidney is unremarkable. Cardiac sonographic examination reveal multiple well-circumscribed myocardial mass in the left ventricle. Biopsy of the renal mass reveal distorted vessles with thick walls, scattered adipose tissue and bundles of spindle cells. There is no ev

Practice question answers Kidney mass I © Jun Wang, MD, PhD 1. A. The history and pathological findings are most compatible with autosomal dominant polycystic kidney disease .   Autosomal recessive (childhood) polycystic kidney disease usually presents at younger age with renal failure and pulmonary hypoplasia. Absence of cytological atypia is not supportive of cystic renal cell carcinoma . Medullary sponge kidney is usually associated with stones, infections, and has normal-sized kidney. Simple cysts are usually incidental findings and not associated with enlarged kidney and liver involvement. 2. B. Autosomal dominant polycystic kidney disease is associated with mutation of PKD1 or PKD2. NPHP mutation is seen in nephronophthisis . PKHD mutation is seen in autosomal recessive polycystic kidney disease . TFE3 abnormality is seen in Xp11 translocation type renal cell carcinoma. VHL mutation is seen in von Hippel-Lindau syndrome and associated clear cell type renal cel

Practice questions I Renal cysts © Jun Wang, MD, PhD 1. Use this case for next four questions . A 39-year-old man presents with vague right flank pain for 6 months. He has a history of intermittent headache and hypertension. Physical examination reveal a blood pressure at 160/110 mmHg and bulging abdomen. His vital signs are otherwise normal. No other abnormalities are seen. No mass can be palpated. CBC and liver, renal functions tests are within normal range. Abdominal sonographic examination reveals multiple cystic changes in enlarged kidneys and liver. Kidney biopsies reveal cysts lined by flattened epithelium in a background of fibrosis. Scattered normal appearing glomeruli are seen. No cytological atypia nor necrosis are seen. What is the most likely diagnosis? A. Autosomal dominant polycystic kidney disease B. Autosomal recessive polycystic kidney disease C. Cystic renal cell carcinoma D. Medullary sponge kidney disease E. Simple cyst 2. A 39-year-old man