Case of the Week

2021-19/ May 10

Contributors: Maiara Ferreira de Souza and Daniel Athanazio

A man in his early 70s underwent prostate needle biopsy due to elevated serum PSA (3.4ng/ml) and a PI-RADS 4 lesion in the right apex. Images are from the targeted biopsy.

Click on the below thumbnails to enlarge photos.

Quiz

1. In this area, what would be your diagnosis?

a) Prostatic adenocarcinoma, Gleason score 3 + 3 = 6

b) Prostatic adenocarcinoma, Gleason score 3 + 4 = 7

c) Prostatic adenocarcinoma, Gleason score 3 + 5 = 8

d) Carcinoid tumor, Gleason grade not applicable

Among prostate adenocarcinoma, Paneth cell-like change describes the presence of cells with prominent eosinophilic granules that stain for chromogranin and contain neurosecretory granules at electron microscopy. It may appear as scattered cells within neoplastic glands or may diffusely involve glands or form nests. A solid pattern of growth would invoke the assignment of Gleason pattern 5. However, the bland cytology, the common limited distribution, and the available follow up data from patients indicate that these solid foci do not predict a more aggressive behavior (as a Gleason pattern 5 diagnosis would imply). As suggested by Epstein and colleagues, we would not grade these Paneth cell-like change foci giving a comment on the probable indolent nature of these lesions.

In a reproducibility study among urologic pathologists, Paneth cell-like changes in tumor nests within a prostate adenocarcinoma had consensus against the diagnosis of Gleason pattern 5.

1. Epstein JI, Amin MB, Beltran H, Lotan TL, Mosquera JM, Reuter VE, Robinson BD, Troncoso P, Rubin MA. Proposed morphologic classification of prostate cancer with neuroendocrine differentiation. Am J Surg Pathol. 2014 Jun;38(6):756-67.

2. Salles DC, Mata DA, Epstein JI. Significance of Paneth cell-like differentiation in prostatic adenocarcinoma: a retrospective cohort study of 80 cases. Hum Pathol. 2020 Aug;102:7-12.

3. Shah RB, Li J, Cheng L, Egevad L, Deng FM, Fine SW, Kunju LP, Melamed J, Mehra R, Osunkoya AO, Paner GP, Shen SS, Tsuzuki T, Trpkov K, Tian W, Yang XJ, Zhou M. Diagnosis of Gleason pattern 5 prostate adenocarcinoma on core needle biopsy: an interobserver reproducibility study among urologic pathologists. Am J Surg Pathol. 2015 Sep;39(9):1242-9.

About GUPS

The Genitourinary Pathology Society (GUPS) was formed with the vision of advancing the care of patients with urologic diseases through enhancements of best practices, research, and education in the subspecialty of Urological Pathology.

GUPS is an official Companion Society of the United States and Canadian Academy of Pathology (USCAP).

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