Primary well-differentiated neuroendocrine tumor (WDNT)/carcinoid of the genitourinary tract is rare. Many WDNT reported in the prostate gland have been seen in close association with conventional prostatic adenocarcinoma and/or label for prostate-specific immunohistochemical markers and are best considered prostatic adenocarcinomas with “carcinoid-like” features. We present a case of primary WDNT/carcinoid incidentally detected in a 67-year-old man who underwent radical prostatectomy for Grade group 2 prostatic adenocarcinoma. Morphologically, the neuroendocrine (NE) lesion appeared distinct from the prostatic adenocarcinoma, labeled for NE markers, was negative for prostatic markers (NKX3.1, PSA, and ERG), and showed an overall low Ki-67 proliferation index (<1%). Follow-up was uneventful with no evidence of residual disease or metastasis.
BeltranHRickmanDSParkK, et al.Molecular characterization of neuroendocrine prostate cancer and identification of new drug targets. Cancer Discov. 2011;1(6):487–495.
2.
BeltranHHruszkewyczAScherHI, et al.The role of lineage plasticity in prostate cancer therapy resistance. Clin Cancer Res. 2019;25(23):6916–6924.
3.
DaviesAHBeltranHZoubeidiA. Cellular plasticity, and the neuroendocrine phenotype in prostate cancer. Nat Rev Urol. 2018;15(5):271–286.
4.
WangHTYaoYHLiBGTangYChangJWZhangJ. Neuroendocrine prostate cancer (NEPC) progressing from conventional prostatic adenocarcinoma: factors associated with time to development of NEPC and survival from NEPC diagnosis-a systematic review and pooled analysis. J Clin Oncol. 2014;32(30):3383–3390.
5.
EpsteinJIAminMBBeltranH, et al.Proposed morphologic classification of prostate cancer with neuroendocrine differentiation. Am J Surg Pathol. 2014;38(6):756–767.
6.
MochHHumphreyPAUlbrightTM, et al.WHO Classification of Tumours of the Urinary System and Male Genital Organs. 4th ed. Lyon, France: IARC; 2016.
7.
WHO. WHO Classification of Tumours: Urinary and Male Genital Tumours. Vol. 8, 5 ed. Lyon, France: International Agency for Research on Cancer; 2022.
8.
PearseAG. The cytochemistry and ultrastructure of polypeptide hormone-producing cells of the APUD series and the embryologic, physiologic, and pathologic implications of the concept. J Histochem Cytochem. 1969;17(5):303–313.
9.
AbrahamssonPA. Neuroendocrine cells in tumour growth of the prostate. Endocr Relat Cancer. 1999;6(4):503–519.
10.
AbrahamssonPAWadstromLBAlumetsJFalkmerSGrimeliusL. Peptide-hormone- and serotonin-immunoreactive tumour cells in carcinoma of the prostate. Pathol Res Pract. 1987;182(3):298–307.
11.
BonkhoffHSteinURembergerK. Androgen receptor status in endocrine-paracrine cell types of the normal, hyperplastic, and neoplastic human prostate. Virchows Arch A Pathol Anat Histopathol. 1993;423(4):291–294.
12.
MuraliRKnealeKLalakNDelpradoW. Carcinoid tumors of the urinary tract and prostate. Arch Pathol Lab Med. 2006;130(11):1693–1706.
GilaniSGuoCCLi-NingEMPettawayCTroncosoP. Transformation of prostatic adenocarcinoma to well-differentiated neuroendocrine tumor after hormonal treatment. Hum Pathol. 2017;64:186–190.
15.
GhannoumJEDeLellisRAShinSJ. Primary carcinoid tumor of the prostate with concurrent adenocarcinoma: a case report. Int J Surg Pathol. 2004;12(2):167–170.
16.
SlaterD. Carcinoid tumour of the prostate associated with inappropriate ACTH secretion. Br J Urol. 1985;57(5):591–592.
17.
TashJAReuterVRussoP. Metastatic carcinoid tumor of the prostate. J Urol. 2002;167(6):2526–2527.
18.
WassersteinPWGoldmanRL. Primary carcinoid of prostate. Urology. 1979;13(3):318–320.
19.
FreschiMColomboRNasproRRigattiP. Primary and pure neuroendocrine tumor of the prostate. Eur Urol. 2004;45(2):166–170.
20.
GiordanoSTolonenTTolonenTHirsimäkiSKatajaV. A pure primary low-grade neuroendocrine carcinoma (carcinoid tumor) of the prostate. Int Urol Nephrol. 2010;42(3):683–687.
21.
Goulet-SalmonBBertheEFrancS, et al.Prostatic neuroendocrine tumor in multiple endocrine neoplasia type 2B. J Endocrinol Invest. 2004;27(6):570–573.
22.
WhelanTGatfieldCTRobertsonSCarpenterBSchillingerJF. Primary carcinoid of the prostate in conjunction with multiple endocrine neoplasia IIb in a child. J Urol. 1995;153(3 Pt 2):1080–1082.
23.
HuJHanBHuangJ. Morphologic spectrum of neuroendocrine tumors of the prostate: an updated review. Arch Pathol Lab Med. 2020;144(3):320–325.
24.
ParimiVGoyalRPoropatichKYangXJ. Neuroendocrine differentiation of prostate cancer: a review. Am J Clin Exp Urol. 2014;2(4):273–285.
25.
KlimstraDSBeltranHLilenbaumRBergslandE. The spectrum of neuroendocrine tumours: histologic classification, unique features, and areas of overlap. Am Soc Clin Oncol Educ Book. 2015;35:92–103.
26.
CavalcantiMSGönenMKlimstraDS. The ENETS/WHO grading system for neuroendocrine neoplasms of the gastroenteropancreatic system: a review of the current state, limitations, and proposals for modifications. Int J Endocr Oncol. 2016;3(3):203–219.
27.
AzumiNShibuyaHIshikuraM. Primary prostatic carcinoid tumor with intracytoplasmic prostatic acid phosphatase and prostate-specific antigen. Am J Surg Pathol. 1984;8(7):545–550.
28.
TamasEFEpsteinJI. Prognostic significance of Paneth cell-like neuroendocrine differentiation in adenocarcinoma of the prostate. Am J Surg Pathol. 2006;30(8):980–985.
29.
SoJSGordetskyJEpsteinJI. Variant of prostatic adenocarcinoma with Paneth cell-like neuroendocrine differentiation readily misdiagnosed as Gleason pattern 5. Hum Pathol. 2014;45(12):2388–2393.
30.
ReyesAMoranCA. Low-grade neuroendocrine carcinoma (carcinoid tumor) of the prostate. Arch Pathol Lab Med. 2004;128(12):e166–e168.
31.
AlmagroUA. Argyrophilic prostatic carcinoma: case report with literature review on prostatic carcinoid and “carcinoid-like” prostatic carcinoma. Cancer. 1985;55(3):608–614.
