COW-2020-47

CASE OF THE WEEK

2020-47 / November 23
Contributor: Liwei Jia

A man in his 50s presented with an elevated PSA of 27 ng/ml. A prostate biopsy was performed and all cores had prostatic cancer with 80% to 90% involvement of each core. Subsequent radical prostatectomy was performed and revealed the following findings.

Quiz

1. What is the correct grade based on the photos above?

a. Gleason score 3 + 4 = 7 (Grade Group 2) with tertiary pattern 5

b. Gleason score 4 + 3 = 7 (Grade Group 3) with tertiary pattern 5

c. Gleason score 4 + 3 = 7 (Grade Group 3)

d. Gleason score 3 + 5 = 8 (Grade Group 4)

e. Gleason score 5 + 4 = 9 (Grade Group 5)

1. Gleason score 4 + 3 = 7 (Grade Group 3)

Paneth cell-like change (PCLC) in the prostate refers to coarse cytoplasmic eosinophilic granules in the prostatic epithelial cells, which bear a striking histological resemblance to normal intestinal Paneth cells. Immunophenotypically, these cells express neuroendocrine markers, including synaptophysin and chromogranin, and do not contain lysozyme, unlike intestinal Paneth cells. Ultrastructurally, cytoplasmic neurosecretory granules are observed by electron microscopy. Therefore, they are actually more akin to intestinal neuroendocrine cells. PCLC is seen in a patchy distribution in both benign and malignant prostatic glands. It can be associated with a broad spectrum of prostatic carcinoma (PCa) grades, as well as in PCa previously treated with androgen deprivation therapy. They usually are present as isolated cells or small groups within neoplastic glands. Uncommonly, they are arranged as single cells, cords or nests of tumor cells, which may cause a diagnostic dilemma, as grading them based on architecture would have result in assigning Gleason pattern 5. Follow-up studies show these tumors appear to have a favorable prognosis. Most recently, a retrospective cohort study of 80 cases concluded that, although a minority of PCLC is associated with conventional higher grade adenocarcinoma and have progression after treatment, the majority have favorable findings, justifying the consideration of them as more indolent tumors despite cases in which PCLC resembles Gleason pattern 5. Therefore, it is important to recognize PCLC and only conventional carcinoma should be graded, to avoid inaccurate upgrading.

1. Tamas EF, Epstein JI. Prognostic significance of paneth cell-like neuroendocrine differentiation in adenocarcinoma of the prostate. Am J Surg Pathol. 2006;30:980-985.

2. So JS, Gordetsky J, Epstein JI. Variant of prostatic adenocarcinoma with Paneth cell-like neuroendocrine differentiation readily misdiagnosed as Gleason pattern 5. Hum Pathol. 2014;45:2388-2393.

3. 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;102:7-12.

Liwei Jia, MD, PhD
Assistant Professor
Department of Pathology
UT Southwestern Medical Center
email: Liwei.Jia@UTSouthwestern.edu

Prostate

Paneth cell-like change, prostatic carcinoma