Original contribution Large cell calcifying Sertoli cell tumor: a clinicopathologic study of 1 malignant and 3 benign tumors using histomorphology, immunohistochemistry, ultrastructure, comparative genomic hybridization, and polymerase chain reaction analysis of the PRKAR1A gene ☆ Fredrik Petersson MD, PhD a,c, ⁎ , Stela Bulimbasic MD b , Radek Sima Msc c , Michal Michal MD c , Milan Hora MD, PhD d , Hugo Dominguez Malagon MD, PhD e , Josef Matoska MD, PhD f , Ondrej Hes MD, PhD c a Department of Pathology, National University Health System, Singapore 119074, Singapore b Department of Pathology, University Hospital Dubrava, 10040 Zagreb, Croatia c Department of Pathology, Medical School and University Hospital, Charles University, 304 60 Pilsen, Czech Republic d Department of Urology, Medical School and University Hospital, Charles University, 325 00 Pilsen, Czech Republic e Department of Pathology, Instituto Nacional de Cancerologia (INCAN), Mexico City, United States of Mexico f Department of Pathology, Onkologicky Ustav Sv Anny Bratislava, 812 50 Bratislava, Slovak Republic Received 9 July 2009; revised 13 September 2009; accepted 18 September 2009 Keywords: Testis; Large Cell Calcifying Sertoli Cell Tumor; Immunohistochemistry; PRKAR1A Gene; Comparative Genomic Hybridization Summary Four cases of large cell calcifying Sertoli cell tumor, 3 benign and 1 malignant, with no clinical signs of Carney complex or Peutz-Jeghers syndrome are reported with results of histologic, immunohistochemical, ultrastructural, and comparative genomic hybridization studies. Analysis of PRKAR1A gene was performed on 2 cases. The age range of the patients was 19 to 54 years. The patient with a malignant large cell calcifying Sertoli cell tumor died of disease 4 years after surgery. Patients with benign tumors have had an uneventful follow-up for 1 and 3 years. All tumors were well circumscribed, unencapsulated, and composed of solid sheets, irregular cords, tubular structures, and nests in a fibrous and/or myxoid stroma with cellular atypia in the malignant case. All tumors showed diffuse immunoreactivity for inhibin, vimentin, calretinin, and S100 protein. Focal positivity for cytokeratin (AE1/AE3) was noticed in 1 case. Tumors were negative for CAM 5.2, Mic-2, Melan-A laminin, placental alkaline phosphatase, and α-fetoprotein. The proliferation index was 5% and 10% for 2 of the benign tumors and 30% for the malignant tumor. Comparative genomic hybridization was performed in 2 cases. There was no evidence of any major chromosomal changes. In one case, no PRKAR1A gene mutation was found. In the other case, a heterozygous shift mutation c.65_84dup was found, despite the absence of other clinical signs of Carney complex or Peutz-Jeghers syndrome. Although the combination of large cell calcifying Sertoli cell tumor and PRKAR1A mutation fulfills the ☆ The study was supported by MSM 0021620819 replacement of and support to some vital organs. ⁎ Corresponding author. Department of Pathology, National University Health System, Singapore 119074, Singapore. E-mail address: fredrikpetersson@live.se (F. Petersson). www.elsevier.com/locate/humpath 0046-8177/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.humpath.2009.09.008 Human Pathology (2010) 41, 552–559