title: Small cell-like glandular proliferation of prostate: a rare lesion not related to small cell prostate cancer.
abstract: Small cell-like change (SCLC) is a rare prostate lesion which has been described in only two previous studies (total of eight cases). Its relation to possible neuroendocrine differentiation remained unclear. We evaluated 11 SCLC cases with immunohistochemistry and electron microscopy. SCLC was characterized by crowded hyperchromatic small nuclei with scant cytoplasm, rosette-like structures, finely granular chromatin with indistinct nucleoli, and lack of mitoses, apoptoses, and necroses. In nine cases, SCLC was admixed with high-grade cancer, and in two cases, it represented a separate intraductal process, spatially remote from a low-volume Gleason score 6 (grade group 1) cancer. Only 2/11 SCLC labeled for synaptophysin, chromogranin, and serotonin, although 6/11 were at least focally positive for TTF1. Staining for NKX3.1 and pancytokeratin was typically weak, focal, and markedly reduced compared to the adjacent cancer. SCLC was positive for ERG in 1/8 and for racemase in 6/10 cases, again typically in a focal and weak fashion. There was no immunoreactivity with CD56, p63, or HMWCK. Ki-67 highlighted only rare nuclei (<1 %). No neuroendocrine granules were demonstrated by electron microscopy in four cases that showed no immunoreactivity for neuroendocrine markers. In summary, SCLC is more frequently found in high-grade prostate cancer, but it may also be encountered as a noninvasive lesion in Gleason score 6 (grade group 1) cancer. Importantly, it does not appear to indicate neuroendocrine differentiation. The low-grade cytology, the lack of mitoses and apoptoses, and the minimal Ki-67 reactivity are findings to support its discrimination from a small cell carcinoma.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, 1400 NW 12th Avenue, Room 4076, Miami, FL, 33136, USA. o.kryvenko@med.miami.edu.|Department of Urology, University of Miami Miller School of Medicine, Miami, FL, USA. o.kryvenko@med.miami.edu.|Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA. o.kryvenko@med.miami.edu.
authors.forename: Oleksandr N
authors.initials: ON
authors.lastname: Kryvenko
authors.affiliation: Department of Pathology and Laboratory Medicine, Henry Ford Health System, Detroit, MI, USA.|Josephine Ford Cancer Institute, Henry Ford Health System, Detroit, MI, USA.
authors.forename: Sean R
authors.initials: SR
authors.lastname: Williamson
authors.affiliation: Department of Pathology and Laboratory Medicine, Calgary Laboratory Service and University of Calgary, Calgary, AB, Canada.
authors.forename: Kiril
authors.initials: K
authors.lastname: Trpkov
authors.affiliation: Department of Pathology and Laboratory Medicine, Henry Ford Health System, Detroit, MI, USA.
authors.forename: Nilesh S
authors.initials: NS
authors.lastname: Gupta
authors.affiliation: Department of Pathology and Laboratory Medicine, Calgary Laboratory Service and University of Calgary, Calgary, AB, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Athanazio
authors.affiliation: Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Martin K
authors.initials: MK
authors.lastname: Selig
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, 1400 NW 12th Avenue, Room 4076, Miami, FL, 33136, USA.
authors.forename: Paul Taylor
authors.initials: PT
authors.lastname: Smith
authors.affiliation: R.T. Pathology and Laboratory Medicine Institute, Cleveland Clinic and Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA.
authors.forename: Cristina
authors.initials: C
authors.lastname: Magi-Galluzzi
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, 1400 NW 12th Avenue, Room 4076, Miami, FL, 33136, USA.|Department of Urology, University of Miami Miller School of Medicine, Miami, FL, USA.|Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA.
authors.forename: Merce
authors.initials: M
authors.lastname: Jorda
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D018288:Carcinoma, Small Cell / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor
keywords: Cancer; Intraductal; Prostate; Small cell-like