|LETTER TO THE EDITOR
|Year : 2014 | Volume
| Issue : 4 | Page : 446
Primary yolk sac tumor of the endometrium: A rare entity
N Abhilasha, UD Bafna, VR Pallavi, PS Rathod, S Krishnappa
Department of Gynaecologic Oncology, Kidwai Memorial Institute of Oncology, Dr. M. H. Marigowda Road, Bangalore, Karnataka, India
|Date of Web Publication||1-Feb-2016|
Dr. N Abhilasha
Department of Gynaecologic Oncology, Kidwai Memorial Institute of Oncology, Dr. M. H. Marigowda Road, Bangalore, Karnataka
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Abhilasha N, Bafna U D, Pallavi V R, Rathod P S, Krishnappa S. Primary yolk sac tumor of the endometrium: A rare entity. Indian J Cancer 2014;51:446
Yolk sac tumor (YST) is a malignant germ cell tumor, most commonly having a gonadal  origin but is also seen arising from various extragonadal sites (around 20%) like mediastinum, retroperitoneum, sacrococcygeal region, pelvis, liver, stomach, vulva, vagina, cervix. Primary yolk sac tumor of endometrium is very rare, and only 6 cases have been reported in literature so far, and we are reporting the 7th case in the world English literature.
A 31-year-old nulliparous woman came with history of menorrhagia since 1 year. Clinical examination revealed bulky uterus of 8-10 weeks size. CT scan showed a bulky uterus (9.7 × 3.9 × 5.7 cm) with thickened endometrium (16 mm) and multiple 3-5 mm mesenteric, para-aortic nodes. Endometrial biopsy showed poorly differentiated malignant neoplasm possibly clear cell carcinoma/yolk sac tumor. Total abdominal hysterectomy, bilateral salpingo oophorectomy, infracolic omentectomy with pelvic and para-aortic lymph node dissection was done. Both fallopian tubes and ovaries were normal, and no evidence of any gross or microscopic extrauterine disease in both pelvis and abdomen. Totally, 12 pelvic lymph nodes and 4 para-aortic lymph nodes were dissected, and none had any evidence of malignancy. Cut section of uterus showed a polypoidal 4 × 4 × 3 cm growth invading less than ½ thickness of myometrium. Microscopy revealed malignant yolk sac tumor [Figure 1] and [Figure 2].
|Figure 1: Yolk sac tumor (H and E, ×40). Section showing the tumor invading the adjacent endometrium|
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|Figure 2: Yolk sac tumor (H and E, ×40). Reticular pattern-tumor cells arranged in a loose meshwork with many empty spaces|
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Immunohistochemistry done was positive for CK, PLAP, AFP, CD117 and negative for CK7, CD10, CD 15, CD 30, SMA, MyoD1, Desmin, EMA. Pre-op raised serum a-feto protein (242.3 IU/ml) normalized (11.7 IU/ml) by 2 weeks post-op. Chemotherapy with four 3 weekly cycles of BEP (bleomycin, etoposide, cisplatin) was given, and the patient is now disease-free since 2 years.
Four theories of histogenesis have been proposed. First is the aberrant migration of primordial germ cells during embryogenesis, which remained in the basal layer of endometrium, second is metastasis from an occult ovarian tumor, third from the residual fetal tissues remaining in the uterus and fourth is the origin from somatic cells that have undergone aberrant differentiation.,,
Histology is similar to gonadal YST. Histological differential diagnosis is clear cell carcinoma. Schiller duval bodies are characteristic of YST. Immunohistochemistry for AFP (alpha feto protein) helps in diagnosis. Because of its rarity, appropriate treatment has not yet been standardized. Surgery alone has been unsuccessful in preventing recurrences even in stage 1 disease. In Pileri et al., though the disease was confined to uterus, it recurred with hepatic metastasis after surgery, probably depicting the aggressive nature of YST, similar to its ovarian counterpart requiring adjuvant treatment despite early stage disease. A combination of surgery and chemotherapy seems to have a good outcome. In Rossi et al., hysterectomy with adjuvant chemotherapy with ovarian preservation was done in a stage 2 patient, and the patient is disease-free since 6 years. Chemotherapy with BEP/VAC regimen is the recommended chemotherapy for germ cell tumors of ovary and hence is used in YST endometrium and seems to be effective., Late stages seems to have a worse prognosis even with surgery and chemotherapy as evidenced in Clement et al. But, experience is limited for recommendations and standardization of treatment protocols.
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[Figure 1], [Figure 2]