GPR: 2019 - Week 45

From MGH Learn Pathology

Clinical history

68 y.o. M with past medical history of HIV, diabetes, and thyroid cancer is admitted for altered mental status. The patient dies in the hospital, and this finding is present in the kidneys bilaterally on autopsy.

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GPR19-36 -GPR 11-4-19 photo 1.JPG

Acute pyelonephritis (bacterial)
Ascending pyelonephritis (route of infection in 95%)
  • Kidneys are enlarged and edematous
  • Characteristic yellow streaks in medulla corresponding to collecting ducts filled with pus
  • Cortical abscesses and necrosis
  • Calyceal dilation due to obstruction or reflux
  • Papillary necrosis often present

Hematogenous acute pyelonephritis

  • Small, subcapsular, yellow abscesses
  • Abscess few mm in diameter

Emphysematous pyelonephritis

  • Gas-filled spaces in the cortex and perirenal fat
  • Planes beneath capsule can have abscesses

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Hereditary papillary renal cancer syndrome

  • Autosomal dominant, associated with germline mutations in the MET proto-oncogene (7q31)
  • Type 1 (low grade, less aggressive) papillary renal cell carcinomas
  • Multifocal, bilateral, well-circumscribed tumors
  • Friable tumor that may “pour out” of kidney
  • Larger tumors may contain hemorrhage and necrosis with cystic degeneration
  • Reported number of tumors range from dozens to 100s in each kidney

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Metastatic cancer to kidney

  • Account for ~3% of all malignant tumors in the kidney
  • Usually multifocal and bilateral. Can be solitary and mimic a primary renal tumor
  • Often in association with concurrent involvement in other organ systems.
  • Tumor emboli in vessels is often present
  • Most common primary sites are lung, colon-rectum, stomach, pancreas, uterus, and skin (melanoma)

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  • Often presents as cortical microabscesses in a miliary distribution
  • Some perinephric abscesses present
  • Papillary necrosis occurs in ~20%
  • Mycotic pseudoaneurysm occluding major renal arteries can occur
  • Microscopically affects glomeruli and may be seen centered around glomeruli
Dr. Lucas Massoth

Dr. Kristen Tomaszewski

Dr. Jakob Moran
Chang, Anthony. Candidiasis. Https://

Haas, NB., Nathanson, K. Hereditary Renal Cancer Syndromes. Adv Chronic Kidney Dis. 2014 Jan; 21(1): 10.1053/j.ackd.2013.10.001. doi: 10.1053/j.ackd.2013.10.001

Kambham, N. Acute pyelonephritis. Https://

Tickoo, SK., Reuter, VE. Hereditary Papillary Renal Cancer and Miscellaneous Other Familial Cancer Syndromes. Https://

Tickoo, SK., Sirohi, D., Reuter, VE. Metastatic Tumors of the Kidney. Https://

Understanding Papillary Renal Cell Carcinoma. NIH CCR.

This week's Gross Pathology Roundup was presented by Michael Marshall, MD, PhD on Mon, Nov 04, 2019.