and Pilar González-Peramato2
KeywordsTesticular neoplasmsTesticular ovarian epithelial-type tumorTesticular juvenile xanthogranulomaTesticular hemangiomaTesticular adrenal rest tumorIntratesticular inflammatory myofibroblastic tumorLow-grade myxofibrosarcoma of the testisMyxoid neurofibroma of the tunica albugineaIntratesticular mesothelial cyst
Under this umbrella term, there are very diverse entities that only share their absolutely no relationship with germ cell tumors nor with those of the gonadal stroma. Even within the diversity of the entities, it is possible to clearly differentiate four groups of tumors: ovarian epithelial-type tumors, juvenile xanthogranuloma, vascular tumors, and other tumors. Examples of tumors reminiscent of the tumors of the epithelial-like ovarian surface include an example of each of the following entities: serous cystadenoma, serous borderline tumor, serous cystadenocarcinoma, and endometrioid adenocarcinoma. In the subgroup of juvenile xanthogranuloma, an example of this tumor is included in the pediatric age and another one in the adult with its peculiar differential diagnoses. The subgroup of vascular tumors is represented by three cases: the first one a capillary hemangioma, the second one a hemangioma in the pubertal age with macroorchidism, and the third one a curious case of diffuse hemangiomatosis of the testicle. The fourth subgroup consists of examples of each of the following entities: testicular adrenal rest tumor, intratesticular inflammatory myofibroblastic tumor, low-grade myxofibrosarcoma of the testis, myxoid neurofibroma of the tunica albuginea, and intratesticular mesothelial cyst.
5.1 Ovarian Epithelial-Type Tumor
Case 79. Nonpapillary Serous Cystadenoma of the Epididymis
Clinical case. A 51-year-old patient with a slowly increased left testicle. The testicular tumor markers were negative. The ultrasonography revealed a paratesticular unilocular cystic lesion, 4 cm in diameter, and multiple small cystic formations in the head of the epididymis.
Comment. The cystic formation meets the morphological and immunohistochemical characteristics of a serous cystadenoma of the epididymis. It is a benign neoplasm of Müllerian origin. It is a very uncommon neoplasm: half a dozen cases have been reported. The age of presentation varies from 12 to 64 years. In one case, it has been described associated to bilateral Sertoli cell adenomas in a patient with CAIS. The mucinous cystadenoma of the testicle and paratesticular structures is even less frequent. It is important to keep this tumor in mind when diagnosing testicular and paratesticular cystic lesions, as a simple excision is curative. The differential diagnosis must be considered with borderline variants and other cystic formations such as spermatoceles and mesothelial cysts.
Fernandez-Aceñero MJ, Renedo G, Fortes J, Manzarbeitia F. Non-papillary serous cystadenoma of the epididymis: cases of a rare entity.Urology. 2010;75:563–5.
AbdullGaffar B, Al-Hasani S, El-Fayomy A. Multiple bilateral nonpapillary serous cystadenoma of the epididymis. Urology. 2013;82:e24–5.
Fernandez-Vega I, Santos-Juanes J, García-Pravia C. Bilateral Sertoli cell adenoma in gonads, associated with serous cystadenoma. Pol J Pathol. 2014;65:154–6.
Kim G, Kwon D, Na HY, Kim S, Moon KC. Mucinous cystadenoma of the testis: a case report with immunohistochemical findings. J Pathol Transl Med. 2017;51:180–4.
Draeger DL, Kraeft SK, Protzel C, Hakenberg OW. A paratesticular multicystic tumor of the tunica vaginalis testis as rare paratesticular cystadenoma. Urol Int. 2018;101:245–8.
Case 80. Serous Borderline Cystadenoma of the Testis
Clinical case. Adult patient with tumor in the left testicle. The rest of the clinical data are unknown.
Comments. The architectural and cytological features are typical in this case of a borderline serous tumor. The differential diagnosis of this intratesticular neoplasia could be posed with adenocarcinoma of the rete testis and malignant mesothelioma. The adenocarcinoma of the rete testis is a tumor centered in the mediastinum, it does not have a capsule and it infiltrates the testicular parenchyma. Malignant mesothelioma is usually an extratesticular tumor and its immunohistochemical profile (positive for D240, thrombomedulin, and calretinin) is different from the immunohistochemical markers of cystadenoma [expression for CK7, EMA, CD15 (Leu-1), CA125 (cancer antigen 125) PAX8, Ber-EP4, and mutation of BRAAF V600E in some cases]. Epithelial tumors of the testis and paratesticular structures of the ovarian type are very rare, with six subtypes: serous, mucinous, endometrioid, clear cell, transitional (Brenner), and squamous. Serous tumors are more frequent than mucinous ones, similarly to what occurs in the ovary. Serous and mucinous tumors may be benign (cystadenomas), borderline, and malignant (carcinomas). It is suggested that their origin would be a Müllerian metaplasia of the epithelium (mesothelial intratesticular inclusions during the development).
Kosmehl H, Langbein L, Kiss F. Papillary serous cystadenoma of the testis. Int Urol Nephrol. 1989;21:169–74.
Meister P, Keiditsch E, Stampfl B. Intratesticular papillary cystadenoma. A rare analogue of serous papillary cystadenoma of the ovary. Pathologe. 1990;11:183–7.
Albino G, Nenna R, Inchingolo CD, Marucco EC. Hydrocele with surprise. Case report and review of literature. Arch Ital Urol Androl. 2010;82:287–90.
Olla L, Di Naro N, Puliga G, Tolu GA. Intraparenchymal serous papillary cystadenoma of the testis: a case report. Pathologica. 2013;105:15–7.
Bürger T, Schildhaus HU, Inniger R, Hansen J, Mayer P, Schweyer S, Radzun HJ, Ströbel P, Bremmer F. Ovarian-type epithelial tumours of the testis: immunohistochemical and molecular analysis of two serous borderline tumours of the testis. Diagn Pathol. 2015;10:118.
Hsieh A, Miller M, He W, Shin D. Serous borderline tumor of the testis and associated magnetic resonance imaging findings. Urol Case Rep. 2017;14:30–2.
Aravind S, Nayanar SK, Varadharajaperumal R, Satheeshbabu TV, Balasubramanian S. High grade serous cystadenocarcinoma of testis-case report of a rare ovarian epithelial type tumour. J Clin Diagn Res. 2017;11:ED13–5.
Scholz B, Beckert M, Mordstein V, Hohmann N, Walther R, Papadopoulos T. Seromucinous borderline tumor of the testis-A case report. Hum Pathol. 2017;60:188–91.
Lin M, Awalt H, Ayala AG, Ro JY. Clear cell carcinoma of testis: A review. Ann Diagn Pathol. 2019;40:26–9.
Case 81. Mucinous Cystoadenocarcinoma of the Testis
Clinical case. A 56-year-old patient who presented with a 3-month-long thickening of the right testicle. The ultrasound showed a hypoechoic 3.5-cm nodule with anechoic areas. The left testicle and both epididymis were normal. Testicular tumor markers stayed within normal limits. The patient presented with an enlargement of the left testicle 4 months later. The ultrasonography disclosed a 2.5 cm in diameter tumor in the epididymis. Both tumors were removed. The digestive tract exploration was normal.
Comments. The present tumor is morphologically similar to tumors of the intestinal-type ovarian surface epithelium. The differential diagnosis focuses on ruling out the metastasis of a tumor of the digestive tract, lung, prostate, and infiltration of the primary rete testis, epididymis, and testicular appendix, so these organs must be thoroughly explored, not only from the clinical point of view, but with the use of different immunohistochemical protocols. Half a dozen cases of cystadenocarcinomas or primary mucinous testicular adenocarcinomas have been reported, of which more than half developed distant metastases.
Elbadawi A, Batchvarov MM, Linke CA. Intratesticular papillary mucinous cystadenocarcinoma. Urology. 1979;14:280–4.
Nistal M, Revestido R, Paniagua R. Bilateral mucinous cystadenocarcinoma of the testis and epididymis. Arch Pathol Lab Med. 1992;116:1360–3.
Ulbright TM, Young RH. Primary mucinous tumors of the testis and paratestis: a report of nine cases. Am J Surg Pathol. 2003; 27:1221–8.
Elliott JE, Klein JR, Drachenberg DE. Primary testicular mucinous neoplasms: case report and literature review. Can Urol Assoc J. 2010;4:E112–5.
Iuga AC, Mull J, Batra R, Miller W. Mucinous cystadenocarcinoma of the testis: a case report. Hum Pathol. 2011; 42:1343–7.
Azuma T, Matayoshi Y, Nagase Y. Primary mucinous adenocarcinoma of the testis. Case Rep Med. 2012;2012:685946.
Celdrán JO, Rodríguez CS, Valverde FM, Compiano LO. Primary mucinous cystadenocarcinoma of the testis: An extremely rare ovarian-type surface epithelial carcinoma. J Cancer Res Ther. 2015;11:647.
Case 82. Endometrioid Adenocarcinoma of the Testis
Clinical case. A 56-year-old patient who presented with a tumor in the right testicle. He states having received neither a hormonal treatment (estrogen) nor chemotherapy. Serum levels of testicular tumor markers were negative.
Comments. The tumor shows a pure glandular pattern. When in the presence of a glandular pattern, it is necessary to consider three situations: metastasis of an adenocarcinoma, somatic-type adenocarcinoma in a teratoma, and glandular pattern of yolk sac tumor. Once metastasis has been discarded after clinical investigation and an adequate immunohistochemical staining, the differential diagnosis continues between somatic-type adenocarcinoma and glandular (endometrioid) pattern of the yolk sac tumor. Both tumors are usually observed to also form part, to a greater or lesser extent, of a mixed germ cell tumor. Histologically, the glands of both tumors show differential features: while in the somatic-type adenocarcinoma the vacuoles that the cells may show are usually supranuclear, in the endometrioid pattern of the yolk sac tumor they are both subnuclear and supranuclear. Immunohistochemically, while in the first the cells show positivity for CK7 and EMA, in the second one they express glypican-3 and AFP. In the event that the tumor, as in the present case, has an endometrioid pattern, it is not associated with another germ cell tumor, it is present in an older adult and there is no previous history of chemotherapy due to germ cell tumor, an endometrioid adenocarcinoma must be considered. In these cases, the cells are positive for CK7 and EMA and, which is pathognomonic, they are associated with endometriosis foci.
Numakura K, Tsuchiya N, Tsuruta H, Obara T, Saito M, Inoue T, Narita S, Horikawa Y, Satoh S, Nanjyo H, Habuchi T. A case of intratesticular endometrioid papillary cystadenocarcinoma. Jpn J Clin Oncol. 2011;41:674–6.
Magers MJ, Kao CS, Cole CD, Rice KR, Foster RS, Einhorn LH, Ulbright TM. Somatic-type malignancies arising from testicular germ cell tumors: a clinicopathologic study of 124 cases with emphasis on glandular tumors supporting frequent yolk sac tumor origin. Am J Surg Pathol. 2014;38:1396–409.
Obliers A, Hinz R, Erbersdobler A. Endometrioid borderline tumor of the testis. A rare cause of cystic neoplasia. Pathologe. 2014;35:504–7.
Hazarika P. Endometrioid like yolk sac tumor of the testis with small teratomatous foci: a case report and review of the literature. Indian J Pathol Microbiol. 2015;58:557–9.
Chander A, Otis CN, Cole LL. Pure glandular endometrioid-like yolk sac tumor of the testis. Int J Surg Pathol. 2015;23:30–1.
5.2 Juvenile Xanthogranuloma
Case 83. Juvenile Xanthogranuloma
Clinical case. A 1-year-old patient with left testicle enlargement. The ultrasound showed a 0.7-cm in diameter perfectly delimited lesion. Testicular tumor markers were negative. Enucleation was performed.