COW-2020-06

CASE OF THE WEEK

2020-6 / FEBRUARY 10
(CONTRIBUTOR: JONATHAN EPSTEIN)

A 58 year old man presented with a cystic 8.0 cm. mass in the testis.

Quiz

1. What is the correct diagnosis?

a. Choriocarcinoma

b. Metastatic squamous cell carcinoma

c. Epithelioid trophoblastic tumor

d. Somatic malignancy arising in a teratoma

1. Epithelioid trophoblastic tumor

The tumor consisted a mixture of squamoid cells with abundant pink “hard” cytoplasm and mostly single, pleomorphic, and hyperchromatic nuclei with variably prominent nucleoli. Occasional multinucleated cells were also present. The cytoplasmic membranes were well defined and prominent without discernible intercellular bridges. The tumor lacked the dimorphic population of syncytiotrophoblasts and cytotrophoblasts along with hemorrhagic necrosis typical of choriocarcinoma. The cyst was lined by extracellular fibrinoid material. The lesion stained diffusely positive for p63, positive for HCG, and focally for GATA3. This immunoprofile and morphology is classic for epithelioid trophoblastic tumor (ETT). In contrast to choriocarcinoma, ETT in the testis when totally excised should have an excellent prognosis. However, close follow up is warranted due to the rarity of these lesions in the testis with limited reported follow-up.

Idrees MT, Kao CS, Epstein JI, Ulbright TM. Nonchoriocarcinomatous Trophoblastic Tumors of the Testis: The Widening Spectrum of Trophoblastic Neoplasia.
Am J Surg Pathol. 2015 Nov;39:1468-78

Jonathan Epstein
Johns Hopkins Hospital
jepstein@jhmi.edu

Testis

Choriocarcinoma, Epithelioid trophoblastic tumor