COW-2019-23

CASE OF THE WEEK

2019-23 / JULY 15
(CONTRIBUTOR: SOUNAK GUPTA)

A 33-year old male with a prior history of a desmoplastic medulloblastoma was found to have a 1 cm left testicular mass on follow up. Representative images of this lesion are shown. The immunophenotype is as follows:

Positive: SF1, S100, CD68 and vimentin

Negative: calretinin, inhibin, CK AE1/3, CD31, CD34, SMA, melan A, HMB45, CD163

Quiz

How would you classify this tumor based on the provided images?

a. Testicular germ cell tumor

b. Leydig cell tumor

c. Sertoli cell tumor

d. Metastatic tumor

Sertoli cell tumor

This lesion is confined to the testicular parenchyma and entrapped seminiferous tubules are seen within the lesion as well as at the periphery of the lesion. Many of these seminiferous tubules show a Sertoli cell only pattern and active spermatogenesis or germ cell neoplasia in situ is not identified. The morphology and location of this tumor raised the possibility of a sex cord stromal tumor and as these often express SF1, this was pursued. Diffusely positive nuclear expression of SF1 was noted.
Recent studies have shown that over two-thirds of Sertoli cell tumors show nuclear expression of beta-catenin, correlated with accompanying exon 3 mutations of the CTNNB1 gene. A follow up study revealed a high specificity of this staining pattern as a similar number of Sertoli cell tumors showed nuclear localization of beta catenin while all Leydig cell tumors tested in this study were negative. The nuclear localization of beta catenin in virtually all lesional cells in this case therefore strongly supports a diagnosis of a Sertoli cell tumor.
Given the history of multiple neoplasia, possible syndromal associations were considered. Possible entities include Nevoid basal cell carcinoma syndrome (Gorlin-Lentz Syndrome) which is characterized by germline alterations of PTCH1 and these patients can present with desmoplastic medulloblastomas. However, this syndrome is not associated with sex cord stromal tumors. Other syndromes include DICER1-pleuropulmonary blastoma familial tumor predisposition syndrome, secondary to germline alterations of the DICER1 gene. Both medulloblastomas and ovarian sex-cord stromal tumors have been described to occur as part of this syndrome.

Perrone F, Bertolotti A, Montemurro G et al. Frequent mutation and nuclear localization of β-catenin in sertoli cell tumors of the testis.
Am J Surg Pathol. 2014 Jan;38(1):66-71.

Zhang C, Ulbright TM. Nuclear Localization of β-Catenin in Sertoli Cell Tumors and Other Sex Cord-Stromal Tumors of the Testis: An Immunohistochemical Study of 87 Cases.
Am J Surg Pathol. 2015 Oct;39(10):1390-4.

Gururangan S, Robinson G, Ellison DW et al. Gorlin syndrome and desmoplastic medulloblastoma: Report of 3 cases with unfavorable clinical course and novel mutations.
Pediatry Blood Cancer. 2015 Oct;62(10):1855-8.

Schultz KAP, Williams GM, Kamihara J et al. DICER1 and Associated Conditions: Identification of At-risk Individuals and Recommended Surveillance Strategies.
Clin Cancer Res. 2018 May 15;24(10):2251-2261.

Schultz KA, Yang J, Doros L et al. DICER1-pleuropulmonary blastoma familial tumor predisposition syndrome: a unique constellation of neoplastic conditions.
Pathol Case Rev. 2014 Mar;19(2):90-100.

Sounak Gupta
Memorial Sloan Kettering Cancer Center
guptas1@mskcc.org

Testis

Sertoli cell tumor, beta catenin, testis