[797] Revisiting the Atypical or So-Called "Anaplastic" Seminoma with Emphasis on Diffuse Atypia

Isabel Alvarado-Cabrero, Narciso Hernandez-Toriz, Gladell P Paner. Mexican Oncology Hospital, IMSS, Mexico City, Mexico; University of Chicago, Chicago, IL

Background: A subset of seminoma may exhibit greater degree of cellular pleomorphism and increased mitotic activity. There is controversy in the literature regarding the clinical relevance of this histologic finding. Some authors suggested this change to represent an early step in transformation toward a more aggressive phenotype because of the higher stage presentation, while others suggested not to designate them as atypical because there is no need for a different therapeutic approach.
Design: We present the clinicopathological features of 20 atypical seminomas with diffuse cellular atypia (present in >50% area) identified from retrospectively reviewed histology slides of 1,010 tumoral orchiectomies (1999-2011) from a national oncology institution. Seminomas with focal cellular atypia or fixation artifacts were not included.
Results: Patient age ranged from 31 to 46 years old (mean 36 years). Tumor involved the right (7/19), left (10/19) and both (2/19) testis. Foci of atypical seminomas were characterized by solid growth of crowded cells containing larger, irregular nuclei, with darker chromatin and increased mitotic activity. These areas were devoid of papillary, tubular or glandular architectures. The "higher grade"-appearing seminoma cells occasionally transitioned or blended imperceptibly with solid seminoma foci. No other germ cell tumor component was present. Stage of 19 cases at presentation was pT1 (15), pT2 (4); N0 (17), N1 (1), N3 (1); and M0 (19). Serum tumor markers in 20 cases were S0 (3), S1 (16) and S2 (1). Eleven patients were treated with radiotherapy and 3 patients (with pT2, N1 and N3) received bleomycin, etoposide and platinum (BEP) chemotherapy. Follow-up on 19 patients (48-96 months, median 60 months) showed all patients were alive with no evidence of disease.
Conclusions: This study shows that presence of the so-called "anaplastic" features even when involving >50% area of seminoma does not predict a high stage presentation and poorer outcome. Thus, presence of these atypical features may not necessitate separation from seminoma, including when choosing the type of therapy for the patient.
Category: Genitourinary (including renal tumors)

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 211, Tuesday Afternoon


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