Vulvar yolk sac tumor mixed with embryonal carcinoma in a peri-pubertal girl: A case report

Pediatric vulvar malignancies: rare but important to know

Malignancies of the vulva in the pediatric population are exceptionally rare, which makes it difficult to gain any insight into their clinicopathologic profile. In this review, we summarize all published cases of a vulva malignancy in pediatric patients (≤21 years) reported in the English language literature for the 50-year period between 1970 and 2020. We estimate that less than 100 malignancies have been reported in total, approximately 50% of which were rhabdomyosarcomas. Invasive squamous cell carcinomas, yolk sac tumors, Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) and melanomas each represented approximately 10% of reported cases. For rhabdomyosarcoma, the alveolar and embryonal subtypes were reported with equal frequency, with both representing 70% of cases combined. The average patient age was 9.8 years. 48% and 35% were Intergroup Rhabdomyosarcoma Study clinical groupings I and III respectively. Managements were generally multimodal, and overall outcomes for the group were favorable. For invasive squamous cell carcinoma, the patients were all in their teenage years, with an average age at diagnosis of 15.2 years. A small subset of cases were associated with human papillomavirus and immunosuppression, and it is possible that immunosuppression has a role in vulvar squamous carcinogenesis in this population. One case was associated with lichen sclerosus. The patients with yolk sac tumors ranged in age from less than 1 year to 20 years (mean 12) and 67% of cases were stage I at presentation. An insufficient number of cases have been reported to define their prognosis, although some cases were notably aggressive. The few reported cases of melanoma are distinctive only because they were all associated with lichen sclerosus, suggestive of some role for the latter in their pathogenesis. The average age of patients reported with ES/PNET was 15 years (range 3.3 to 20). At least half of the reported cases were advanced stage at presentation, and patient outcomes were notably poor: 62.5% were dead of disease at follow-up. Pediatric vulvar malignancies are rare and are mostly comprised of 5 entities. Their accurate pathologic classification is necessary to facilitate optimal management.

Yolk Sac Tumor in Extragonadal Pelvic Sites: Still a Diagnostic Challenge

We present the clinicopathologic features of 15 cases of extragonadal yolk sac tumor (EGYST) detected in female patients and reviewed at our institution from 1988 to 2016. We recorded: patient age, clinical presentation, tumor location, FIGO stage (where applicable), histologic patterns including presence/absence of Schiller-Duval bodies, other germ cell or somatic components, immunoperoxidase results, treatment, and outcome. Patients' ages ranged from 17 to 87 (median, 62) years and presentation included: abnormal uterine bleeding, 12; hematuria, 1; labial mass, 1; abdominal pain, 1. Primary sites were as follows: uterus (11), vagina (1), vulva (1), bladder (1), and peritoneum (1). Seven patients presented at FIGO stage III or IV. The following histologic patterns were observed: microcystic/reticular (7), glandular (8), solid (8), papillary (5), and hepatoid (1). An admixture of histologic patterns was present in 10 cases. Schiller-Duval bodies were seen in only 3 (23%) cases. Eight cases (46%), all uterine primaries, had associated somatic components, and 2 (15%) had a second germ cell component. In 13/14 (93%) cases, the yolk sac tumor component was either missed or misclassified as adenocarcinoma. Immunoperoxidase studies facilitated the diagnosis in all cases as follows: SALL4, 12/12; CDX2, 10/12; α fetoprotein, 7/14; glypican-3, 9/10; cytokeratin 20, 5/9 (rare cells); cytokeratin 7, 3/12 (nondiffuse); PAX8, 2/9 (variable expression). All patients received chemotherapy and all except 1 underwent surgical resection. Follow-up from 5 to 86 months was available for 13 patients: 5 died of disease, 6 are alive with disease, and 2 have no evidence of disease. EGYST arising in the female pelvis of peri/postmenopausal patients may be associated with a somatic component and represent either somatically derived YST or YST differentiation within a somatic carcinoma. EGYST in younger patients is likely a true germ cell neoplasm, and may respond to germ cell appropriate chemotherapy. The benefit of germ cell appropriate chemotherapy in somatically derived EGYST is less clear. Awareness that the presence of glandular or microcystic patterns may lead to under-recognition or misdiagnosis of EGYST in combination with immunomarkers for germ cell and yolk sac differentiation will facilitate the diagnosis.

Unusual Presentations of Gynecologic Tumors: Extragonadal Yolk Sac Tumor of the Vulva

Extragonadal germ cell tumors are uncommon, and although they morphologically resemble their gonadal counterparts, unexpected gonadal presentation increases the potential for erroneous diagnoses. Yolk sac tumor is a malignant germ cell tumor characterized by an extraembryonic yolk sac line of differentiation, and relative to other germ cell tumors, is characterized by varied and diverse histologic patterns. When occurring outside of typical age parameters or in extragonadal locations, the histologic variability of yolk sac tumor and its tendency to mimic somatic tumors pose diagnostic challenges. Because extragonadal yolk sac tumor of the vulva is very rare, with only isolated case reports and small series in the literature, it is often not considered in the differential diagnosis. As both prognosis and management of yolk sac tumor differ significantly from those of somatic tumors, accurate diagnosis is essential. This review discusses histologic features of extragonadal yolk sac tumor, addresses somatic tumors arising in the vulva for which yolk sac tumor may be confused, and provides guidance with respect to the use of immunohistochemistry in the diagnosis of yolk sac tumor.

Vulvar yolk sac tumor diagnosed during pregnancy, with recurrence during subsequent second pregnancy

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Vulvar yolk sac tumor (YST) is an exceptionally rare and aggressive extra-gonadal germ cell tumor, previously only described in 15 cases in the literature.

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We present a unique case of vulvar YST diagnosed during pregnancy, treated with systemic chemotherapy, who subsequently recurred during a second pregnancy.

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Despite salvage chemotherapy and autologous stem cell transplantation at recurrence, our patient succumbed to her disease, 31 months post diagnosis.