CASE OF THE WEEK
2020-43 / October 26
Contributor: Daniel Athanazio
A man in his early 50s underwent radical orchiectomy due to a 5.5 cm solid mass in the left testis and a partial orchiectomy for a 1.2 cm solid mass in the right testis. The left testicular mass is shown in figures 1 (gross), 2, 3 and 5. Figure 4 shows the tumor in the right testis, and its transition from a solid mass to areas of intratubular growth (which were absent in the larger mass).
Quiz
1. What is the correct diagnosis?
a) Seminoma with atypia (formerly anaplastic seminoma)
b) Spermatocytic tumor, anaplastic variant
c) Anaplastic B-cell lymphoma
d) Epithelioid trophoblastic tumor
e) Embryonal carcinoma
1. b
1. Spermatocytic tumor, anaplastic variant
Spermatocytic tumor (formerly spermatocytic seminoma) is a germ cell tumor derived from postpubertal-type germ cells. The tumor is usually solid and multinodular showing a characteristic pattern of polymorphous population of large/giant, intermediate and small cells that resembles the differentiation from spermatogonia to spermatocytes and spermatids.
In this case, immunohistochemistry was helpful to exclude some differential diagnoses. A panel of negative markers included OCT3/4 (ruling out seminoma), CD30 (embryonal carcinoma), C45, CD3 and CD20 (lymphoma), inhibin (malignant Sertoli tumor) and GATA3 (trophoblastic tumors). The only positive markers were c-KIT/CD117 (diffuse membrane staining) and cytokeratin 8/18 (focal). Other markers such as SALL4 and MAGEA4, reported to be expressed in most spermatocytic tumors, were not available in our service.
Some spermatocytic tumors may show extensive areas that lack the polymorphous population of cells and are replaced by more uniform intermediate cells with prominent nuclei or may show large and bizarre cells. This rare morphologic presentation has been called anaplastic variant of spermatocytic tumor (formerly anaplastic variant of spermatocytic seminoma). The WHO 2016 classification discourages the use of this terminology because the available data suggest that this undifferentiated phenotype does not affect prognosis. Even though these tumors usually show high mitotic count, frequent atypical mitoses and anaplasia, the prognosis is excellent. In contrast, sarcomatous transformation of spermatocytic tumors is a well-documented phenomenon that indicates aggressive behavior and poor prognosis. No sarcomatous areas were seen in this case.
Spermatocytic tumors are bilateral in 9% of all cases in contrast to only 2% of seminomas. Some spermatocytic tumors show intratubular growth resembling the same polymorphous patterns of the main tumor (see Figure 4). Such intratubular extension is not considered germ cell neoplasia in situ (GCNIS) and, by definition, spermatocytic tumors are unrelated to GCNIS. Both features of bilaterality and intratubular extension were observed in this case.
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Dundr P, Pesl M, Povýsil C, et al. Anaplastic variant of spermatocytic seminoma. Pathol Res Pract. 2007;203(8):621-624.
Gentile G, Giunchi F, Schiavina R, et al. First case of bilateral, synchronous anaplastic variant of spermatocytic seminoma treated with radical orchifunicolectomy as single approach: case report and review of the literature. Arch Ital Urol Androl. 2014;86(1):41-42.
Lombardi M, Valli M, Brisigotti M, Rosai J. Spermatocytic seminoma: review of the literature and description of a new case of the anaplastic variant. Int J Surg Pathol. 2011;19(1):5-10.
Moch H, Humphrey PA, Ulbright TM, Reuter VE. Chapter41 Tumours of the Testis and Paratesticular tissues. In: WHO Classification of Tumours of the Urinary system and male genital organs. Lyon: IARC; 2016. p. 218-221
Daniel Athanazio
Professor of Medicine, Federal University of Bahia
Imagepat, Laboratory of Pathology
Salvador, Bahia, Brazil
Testis
Testis; Testicular Neoplasms; Germ cell tumors