| Abstract|| |
I have reported a case of endometrioid like yolk sac tumor of the testis in a 20-year-old boy. Endometrioid like yolk sac tumor is a rare tumor. A few cases have been reported in ovary. In case of male, a case of pure glandular endometrioid like yolk sac tumor is reported in a 43 years male in right undescended testis and another case of abdominal metastasis showing endometrioid pattern from mixed testicular germ cell tumor comprising of teratoma and embryonal carcinoma. My patient was a 20-year-old male presented with painless enlargement of right testis. Grossly the tumor was glistening creamish white with a multicystic appearance. Histopathological examination showed the tumor to be composed of glandular elements resembling early secretory endometrium, foci of keratinized thin squamous epithelium and a single focus of benign cartilage. The glandular elements show immunohistochemical positivity for AFP, cytokeratin 7 (CK7) and epithelial membrane antigen (EMA).
Keywords: Endometrioid, orchidectomy, teratoma, yolk sac tumor
|How to cite this article:|
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
|How to cite this URL:|
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 [serial online] 2015 [cited 2020 Jan 21];58:557-9. Available from: http://www.ijpmonline.org/text.asp?2015/58/4/557/168869
| Introduction|| |
Yolk sac tumor is a germ cell neoplasm of both male and female. It involves children and young adults. It can occur either in pure form usually in younger children or as a component of mixed germ cell tumor in adolescent or early adulthood. Yolk sac tumors show several histological patterns – endodermal sinus, microcystic, papillary, glandular-alveolar, myxomatous, sarcomatoid, polyvesicular vitelline, hepatoid and parietal. It is associated with elevation of serum alpha fetoprotein (AFP) level. Furthermore, the tumor shows positivity for AFP immunohistochemically. Endometrioid like yolk sac tumor is a rare tumorfirst reported by Clement et al. A few cases have been reported in ovary  and two cases in male so far. One of them primarily involved testis  while other was a metastases in the abdominal cavity from a mixed testicular germ cell tumor with teratoma and embryonal carcinoma.
Clement et al. reported eight cases of ovarian yolk sac tumor with endometrioid like pattern. The average age of the patients was 22 years (range 11-34 years). The patients presented with abdominal pain and swelling. Their serum AFP level was elevated. Seven tumors were unilateral, one was bilateral and three had extraovarian spread. In histopathological examination, two of the tumors showed pure endometrioid like glandular pattern that often resembled that of an early secretory endometrium. Reticular, polyvesicular-vitelline, and hepatoid pattern of yolk sac tumor was also present in five tumors; minor teratomatous foci (squamous epithelium and cartilage) was present in one. The tumors showed positive staining for AFP, alpha-1-antitrypsin (AAT) and carcinoembryonic antigen in the glandular elements. AFP and AAT were also present in areas showing the other patterns. Three of the patients succumbed to death due to tumor and rests had a disease-free follow-up of short duration. Chander et al. reported a case of pure glandular endometrioid like yolk sac tumor in right undescended testis in a 43-year-old man. Grossly, the tumor was heterogeneous with hemorrhagic cystic foci located at the lower pole of the testis. Microscopically, the tumor was well circumscribed and contained multiple hemorrhagic and cystic area with tubulopapillary glands lined by columnar cells with prominent subnuclear and supranuclear cytoplasmic vacuolation. The tumor was negative for AFP, CD30. October ¾, renal cell carcinoma antigen and PAX8. Glipican 3 was positive and epithelial membrane antigen (EMA) was focally positive.
The other case reported in male was a 36-year-old man with a past history of mixed germ cell tumor of the testis comprising of immature teratoma and embryonal carcinoma who was admitted in the hospital due to abdominal pain and fever. Computed tomography (CT) scan revealed an abdominal mass and his serum AFP was elevated. He was administered chemotherapy, following which surgery was performed. Grossly, the abdominal mass was encapsulated with hemorrhagic and necrotic area surrounded by multiloculated cysts. Histological examination showed villoglandular structures lined by variably stratified columnar epithelium displaying supranuclear and subnuclear cytoplasmic vacuolation. The tumor was positive for AFP. Hence, the final diagnosis was endometrioid like yolk sac tumor at metastatic abdominal deposit from the previous mixed testicular germ cell tumor of teratoma and embryonal carcinoma.
| Case Report|| |
Here, I have presented a case of endometrioid like yolk sac tumor of the testis with a scanty component of mature teratoma in a 20-year-old boy who presented with painless right testicular enlargement of 1-month duration. The boy did not have any extratesticular spread at the time of diagnosis confirmed by CT scan examination. His serum AFP was not assessed preoperatively. The clinical diagnosis was seminoma testis. The left testis was unremarkable.
Gross examination of the specimen [Figure 1]a showed replacement of normal testicular tissue by a glistening creamish white tumor with numerous uniformly distributed cystic spaces of up to 5 mm in diameter. There were no grossly detectable foci of hemorrhage and necrosis. The size of the tumor is 5 cm × 3 cm × 2 cm.
|Figure 1: (a). Gross specimen: The tumor is glistening and creamish white in color. There are numerous uniformly distributed cysts up to 0.5 cm in diameter. (b) Microscopically, the tumor is composed of variably sized glands lined by columnar epithelium with supranuclear and subnuclear cytoplasmic vacuolation resembling early secretory endometrium (H and E, ×40). (c) Normal compressed testicular tissue is seen in the capsule of the tumor (H and E, ×10). (d) Focus of mature keratinized squamous epithelium in the tumor. This comprises of only a small component of the tumor (H and E, ×10). (e) The single focus of mature cartilage in the tumor (H and E, ×40)|
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Histological examination [Figure 1]b showed the tumor to be composed of large, some cystically dilated glands and villiform configurations. They are lined by a single layer of columnar cells with subnuclear and supranuclear cytoplasmic vacuolation resembling early secretory endometrium. Foci of necrosis were present although it was not apparent on gross examination. Compressed testicular tissue was present near the peripheral part of the tumor [Figure 1]c. There were few tiny foci of keratinized squamous epithelium [Figure 1]d, a single focus of mature cartilage [Figure 1]e and several foci of immature mesenchyme. Immunohistochemistry showed the endometrial like glands to be positive for AFP [Figure 2]a, cytokeratin 7 (CK7) [Figure 2]b and EMA [Figure 2]c.
|Figure 2: Immunohistochemical staining for (a) Alpha-fetoprotein (×10). (b) CK7 (×10). (c) Epithelial membrane antigen (×10) showing positivity for all the three markers|
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After orchidectomy, the patient has received one cycle of chemotherapy with bleomycin, etoposide and cisplatin. He has been followed-up at each month interval with CT scan and serum AFP level assay for early detection of possible recurrence. He is remaining free from disease during this short follow-up.
| Discussion|| |
Endometrioid like yolk sac tumor is a rare tumor. When it occurs in pure form (without mixed with other pattern of yolk sac tumor), it may cause a diagnostic problem if the reporting pathologist is not aware of this entity. When it is mixed with a mature teratomatous component as like the case presented here, it may be confused with the glandular elements of a mature teratoma. This distinction between mature teratoma with a benign glandular element and endometrioid like yolk sac tumor with foci of teratoma bears significant clinical importance in prepubertal male and female as one condition is essentially benign while the other is malignant. Early secretory endometrium like lining of the glands and villiform structures point toward a proper diagnosis which is further confirmed by positive immunohistochemical staining for AFP. However, mature teratoma in a postpubertal male is always considered malignant because the mature teratomatous component is thought to arise from the differentiation of an immature germ cell tumor. In this case, the teratomatous component presumably arises from the focal differentiation of the yolk sac component.
A significant difference between this case and previously reported cases of endometrioid like yolk sac tumor is that this case showed immunohistochemical positivity for CK7 and EMA in addition to AFP while the previously reported cases showed positivity only for AFP and negativity for CK7 and EMA. In many of the previous studies including a recently reported case of ovarian yolk sac tumor associated with endometrioid adenocarcinoma, immunohistochemistry for AFP, CK7 and EMA was used to differentiate between endometrioid like yolk sac tumor and endometrioid adenocarcinoma of ovary.,, According to them endometrioid like yolk sac tumor are positive for AFP and negative for CK7 and EMA while reverse is the case in case of endometrioid adenocarcinoma. One previously reported endometrioid like yolk sac tumor in metastatic deposit at the abdominal cavity from a mixed germ cell tumor of the testis also showed positivity for AFP and negativity for CK7 and EMA. However, the other reported case of primary testicular yolk sac tumor showed focal positivity for EMA. This is in contrast to its ovarian counterparts.
| Conclusion|| |
As far, I know this is the second reported case of primary endometrioid like yolk sac tumor of the testis. Although a rare tumor, one always have to think about endometrioid like yolk sac tumor when an ovarian or testicular tumor show endometrial type of glands with early secretory pattern. This case is also against the previous concept of endometrioid like yolk sac tumor to be negative for CK7 and EMA, which is being employed to differentiate between this neoplasm and endometrioid adenocarcinoma of the ovary.
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| References|| |
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Dr. Prabir Hazarika
Department of Pathology, Silchar Medical College and Hospital, Silchar, Assam
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2]