DECEMBER 2017 CASE OF THE MONTH
A 17 year old presenting with hematuria
Fatimah Alruwaii, MBBS
Resident in Pathology, PGY2
IU School of Medicine | Department of Pathology and Laboratory Medicine
Howard H. Wu, MD
Professor of Clinical Pathology & Laboratory Medicine
Clinical history: The patient is a 17 year-old man who presented with gross hematuria and flank pain of three weeks duration. A CT of the abdomen/pelvis (Fig. 1A) showed a 6.3 cm right lower pole kidney mass and a 3.2 cm right upper pole kidney mass, in addition to bulky bilateral retroperitoneal lymphadenopathy and possible lung metastases. The patient has a history of sickle cell trait.
FNA and core biopsy: The Diff-Quick and Papanicolaou stained aspirate smears show loosely cohesive clusters of malignant epithelial cells with enlarged mostly centrally and occasionally eccentrically located hyperchromatic nuclei and prominent nucleoli. Many neutrophils are present within the smear background (Fig. 2).
A simultaneously performed core biopsy shows sheets of malignant cells with high nuclear to cytoplasmic ratio, prominent nucleoli, and marked nuclear pleomorphism in a background of desmoplastic stroma and prominent neutrophilic infiltrate (Fig. 3A). Immunohistochemical stains show that the neoplastic cells are positive for AE1/3 (Fig. 4A) and Pax-8 (Fig. 4B) and negative for Oct-4 (Fig. 4C). INI-1 expression is lost within the neoplastic cells (Fig. 4D).
Gross and microscopic examination of the resection specimen: Gross examination of the resection (Fig. 1B) specimen shows an inferior pole mass (6.8 x 4.0 x 3.8 cm) with a lobulated tan cut surface with focal hemorrhage and no necrosis. The mass extends into the hilar fat. Sections from the resection specimen show similar features to the core biopsy in addition to areas showing rhabdoid morphology (Fig. 3B).
Fig.1: CT (A) and gross examination (B) of the right kidney showing a lobulated inferior pole mass
Fig.2: FNA smears showing markedly pleomorphic cells with nuclear atypia and prominent nucleoli in a background of neutrophilic infiltrate
Fig.3: Core biopsy (A) and resection specimen (B) sections showing sheets of malignant cells in desmoplastic background with prominent neutrophilic infiltrate. Some cells have rhabdoid morphology (arrow).
Fig.4: Immunohistochemical stains showing that the tumor cells are positive for AE1/3 (A) and PAX-8 (B), and negative for SMARCB1/INI1 (C) and OCT-4 (D)