GPR: 2019 - Week 41

• GPR Quiz
• Answer
• DDx1
• DDx2
• DDx3

Clinical history

3 year old female with abdominal pain and 10.1 cm mass of R kidney

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Wilms Tumor (Nephroblastoma) 98% of cases in children < 10 years of age Peak incidence: 2-3 years Overall survival >90% Most tumors are unicentric Usually sharply demarcated from surrounding parenchyma Very often encapsulated Often uniformly pale gray or tan with soft consistency More whorled or firm if prominent stromal component Hemorrhage, necrosis, cysts and lobular pattern are common

Malignant Rhabdoid Tumor Highly malignant pediatric renal tumor with very poor prognosis Mortality rate > 80% within 2 yrs of diagnosis Mean age 1 yr Typically large tumor (mean 9.6 cm) Well circumscribed but non-encapsulated with ill-defined borders Fleshy tumor often with hemorrhage and necrosis (Photo credit-ExpertPath)

Congenital Mesoblastic Nephroma Spindle cell neoplasm of the kidney Most common renal tumor in the first 3 months of life Rarely occurs in children >2 yrs Majority cured with surgery and have excellent outcome Solitary, unilateral Whorled or trabeculated gray/white cut surface Indistinct tumor-kidney interface May see hemorrhage, cysts or necrosis

Cystic Nephroma Benign encapsulated neoplasm composed entirely of epithelial lined cysts and thin cyst septa Pediatric lesion associated with DICER1 mutations Typically occurs in those <4 yrs Well circumscribed, encapsulated, diffusely cystic containing clear serous fluid Solid areas may represent sarcomatous transformation

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This week's Gross Pathology Roundup was presented by Kristine Marie Chaudet, MD on Mon, Oct 07, 2019.