Pure intertubular seminoma (PITS) of the testis is described as the presence of seminoma cells within the interstitium of testis without any evidence of diffuse growth pattern or mass lesion of classical seminoma. These tumors are clinically and grossly inconspicuous and are diagnosed incidentally or during investigations for testicular pain, infertility or other symptoms. Rarely metastasis is the first presentation. Microscopic identification can be difficult and poses a diagnostic challenge in the absence of a mass lesion. Seminomas with exclusive intertubular growth patterns were gathered in an international cohort. Diagnoses were confirmed by fellowship-trained or specialized urologic pathologists. Cases with the presence of a classical diffuse or nested pattern of seminoma or any other germ cell tumor component were excluded. The patient's age, tumor characteristics and additional clinicopathologic features were recorded and analyzed. 15 patients of pure intertubular seminoma (PITS) were collated. The mean age of presentation was 29 years. Patients presented with variable symptoms, including undescended testis (26%, n = 4/15), testicular heaviness/pain (20%, n = 3/15) infertility (20%, n = 3/15) and metastasis (6%, n = 1/15); presentation was unknown in 4 patients. Of note, none of the patients presented because of testicular mass. Serum markers were within normal limits in most patients (93%, n = 14/15) with available data. No tumors were identified macroscopically; however, an ill-defined, grey-white, firm area was noted in one orchiectomy specimen. Microscopically, tumor cells were seen in intertubular spaces as dispersed individual cells or small clusters. Tumor cells were round to polygonal with large nuclei and prominent nucleoli. Mild to moderate lymphocytic infiltrates were seen admixed with tumor cells in 40% (n = 6/15) of the tumors. GCNIS was present in association with most PITS (73%, n = 11/15). Tubular atrophy with thickening of the basement membrane and Leydig cell hyperplasia was observed in one tumor. Thirty-three percent (n = 5/15) of the tumors showed pagetoid involvement of rete testis, including the tumor with metastasis. All tumors showed the classical immunohistochemical profile of seminoma, with PLAP, c-KIT, OCT3/4, D2-40 and SALL4 positivity. PITS can be clinically & pathologically inconspicuous, difficult to stage and liable to be misdiagnosed especially if presented with metastasis. Despite the inconspicuousness, PITS may represent an aggressive growth pattern of seminoma with the propensity for rete testis invasion.
Human pathology. 2024 Sep 19 [Epub]
Seema Kaushal, Ekta Jain, Andres M Acosta, Ankur R Sangoi, Anandi Lobo, Shilpy Jha, Shivani Sharma, Samriti Arora, Arshi Beg, Mahmut Akgul, Sean R Williamson, Manas R Baisakh, Niharika Pattnaik, Swati Satturwar, Anil V Parwani, Mallika Dixit, Vipra Malik, Adeboye O Osunkoya, Liang Cheng, Mahul B Amin, Jasreman Dhillon, Sourav K Mishra, Ghanashyam Biswas, Soumya Surath Panda, Sambit K Mohanty
Department of Pathology, All India Institute of Medical Sciences - New Delhi, India., Department of Pathology and Laboratory Medicine, CORE Diagnostics, India., Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, USA., Department of Pathology, Stanford University School of Medicine, USA., Department of Pathology and Laboratory Medicine, Kapoor Pathology and Urology Center, India., Department of Pathology and Laboratory Medicine, Advanced Medical and Research Institute, India., Department of Pathology and Laboratory Medicine, Albany Medical Center, USA., Department of Pathology and Laboratory Medicine, Cleveland Clinic, USA., Department of Pathology and Laboratory Medicine, Prolife Diagnostics, India., Department of Pathology and Laboratory Medicine, Utkal Cancer Hospital, India., Department of Pathology, Ohio State University, Wexner Medical Center, USA., Department of Pathology and Laboratory Medicine, Emory University School of Medicine, USA., Department of Pathology and Laboratory Medicine, Alpert Medical School of Brown University, USA., Department of Pathology, Keck School of Medicine of the University of Southern California, USA., Department of Pathology, Moffitt Cancer Center, USA., Department of Medical and Uro-oncology, All India Institute of Medical Sciences - Bhubaneswar, India., Department of Medical and Uro-oncology, Institute of Medical Sciences and SUM Hospital- Bhubaneswar, India., Department of Pathology and Laboratory Medicine, CORE Diagnostics, India. Electronic address: .