Primary yolk sac tumor of the omentum: a case report and literature review

Germ Cell Tumor Presenting as a Mesenteric Cyst: a Case Report and Literature Review

Mesenteric cysts, typically benign and asymptomatic, are incidental findings during abdominal investigations for nonspecific symptoms. Their origin is commonly in the mesentery of the small bowel, mesocolon, or retroperitoneum. This paper reports a rare case of a 22-year-old male with a mesenteric cyst presenting as a right lower abdominal mass. Ultrasonography revealed a heterogenous collection, leading to surgical excision. Histopathology unexpectedly revealed an extragonadal yolk sac tumor (YST) originating in the mesentery, a rarity often misdiagnosed as a cyst. YST, primarily found in gonads, is infrequently reported extragonadally. This study contributes to the limited literature on primary peritoneal YST, discussing clinicopathological parameters and presenting a detailed case. The pathogenesis of extragonadal germ cell tumors, including YST, remains debated, with migration and stagnation of germ cells during embryonic development proposed as a prevalent theory. Histopathological examination of extragonadal YST mirrors gonadal YST, featuring various patterns. Immunohistochemistry, crucial for diagnosis, reveals positive expression for SALL-4, glypican-3, PLAP, AFP, and panCK. SALL-4 emerges as the most sensitive marker for extragonadal YST. This case underscores the importance of accurate postoperative histopathology and immunohistochemistry in distinguishing mesenteric YST from cysts, as misdiagnosis can impact prognosis. The rarity of extragonadal YST emphasizes the need for comprehensive understanding and recognition in clinical practice. The study contributes valuable insights into diagnosis and management, shedding light on a challenging aspect of surgical pathology.

Yolk sac tumor of postpubertal-type does not exhibit immunohistochemical loss of SMARCB1/INI1 and SMARCA4/BRG1…but choriocarcinoma?

The recently described SWI/SNF complex-deficient sinonasal carcinoma (SMARCB1 & SMARCA4) may exhibit a yolk sac-like morphology. Tumors with similar features (yolk sac-like histology combined with the immunohistochemical loss of SMARCB1/INI1 and/or SMARCA4/BRG1) have also been described in other sites, such as the female genital tract. In this study, we immunohistochemically assessed SMARCB1/INI1 and SMARCA4/BRG1 expression to evaluate if these proteins could be involved in the pathogenesis of testicular yolk sac tumors of postpubertal type (YSTpt). Specifically, we analyzed a retrospective case series comprising pure YSTpt and mixed germ cell tumors of the testis (GCTT) with YSTpt components. In the present study, no testicular YSTpt showed loss of SMARCB1/INI1 (0/24, 0%) or SMARCA4/BRG1 (0/24, 0%). However, testicular choriocarcinoma (CHC) and isolated syncytiotrophoblast cells (iSTCs) demonstrated abnormal staining patterns for SMARCA4/BRG1 [CHC: 4/4 (100%); iSTCs: 12/12 (100%), respectively], including focal or diffuse loss of expression in a subset of cases. The results of our study suggest that functional loss of SMARCA4/BRG1 represents a recurrent event that may be relevant for the pathogenesis of a subset of testicular CHC.

Relapsed and refractory yolk sac tumor of the peritoneum (mesentery): A case report and literature review

Background

Extragonadal yolk sac tumor (YST) of peritoneum is a rare malignancy.

Case Description

A 37-year-old Chinese woman was admitted to hospital with a 3-month abdominal pain 4 years ago. Alpha-fetoprotein was 228,499.0 ng/mL. Computed tomography scan revealed a massive mass in the left lower abdomen. Exploratory laparotomy exposed a huge mesenteric mass. Then, mesenteric tumor resection, partial sigmoidectomy, and single-lumen fistula of sigmoid colon were performed. Postoperative pathologic diagnosis reported a stage IV mesenteric YST. After surgery, the patient received 6 courses of BEP (bleomycin, etoposide, and cisplatin) chemotherapy. Seven months later, the patient underwent stoma reversion of sigmoid colon and received another 2 courses of BEP chemotherapy. Three months after the last chemotherapy, liver metastases were diagnosed. She subsequently underwent 3 surgeries, radiotherapy for liver metastases, and multiple tiers of palliative chemotherapies, including TP (docetaxel and carboplatin), VIP (ifosfamide, cisplatin, and etoposide), TIP (paclitaxel, ifosfamide, and cisplatin), and so on. After the third surgery (left hepatic lesion resection and right iliac lymph node resection), she received 4 cyclic chemotherapies of BEP´ (boanmycin, etoposide, and cisplatin) without pulmonary toxic side effects.

Conclusion

Postoperative histopathology and immunohistochemistry are gold standards for the diagnosis of peritoneal YST. The standard first-line treatment is surgery plus BEP chemotherapy. Second-line therapy regimens and above, including VIP and TIP, improve the prognosis of recurrent germ cell tumors. This relapsed and refractory patient with peritoneal YST benefits from the secondary BEP´ chemotherapy.

Yolk Sac Tumor of the Omentum: A Case Report and Literature Review

This is a case report of a rare finding of an extragonadal yolk sac tumor in a 37-year-old patient who presented with shortness of breath and abdominal bloating. During imaging and staging surgery, the findings were strongly suggestive of an extragonadal advanced tumor presenting with peritoneal dissemination, predominantly affecting omentum, with no clear primary origin. Histology revealed an extragonadal yolk sac tumor in a pure form outside the ovaries. Lacking an obvious origin elsewhere, the tumor was highly suspected to have truly originated from the omentum. The patient underwent surgery and four cycles of chemotherapy consisting of cisplatin, etoposide, and bleomycin. One-year outpatient follow-up thereafter showed no relapse. We herein discuss a possible site of the tumor origin and its development, as well as diagnostic challenges and disease prognosis.

Primary Yolk Sac Tumor in the Cerebellar Hemisphere: A Case Report and Literature Review of the Rare Tumor

Yolk sac tumor (YST) is one of rare malignant germ cell tumors (GCTs). Primary intracranial YST, also endodermal sinus tumor (EST), is a quite rare type of brain tumor. Here, we report a case of YST, review the relevant literature, and propose a treatment strategy for this rare tumor. A 6-year-old boy initially manifested symptoms of dizziness and vomiting. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large irregular oval tumor in the cerebellar hemisphere. We subtotally removed the tumor by microsurgery through the left suboccipital approach. Immunohistochemical staining showed that alpha fetoprotein (AFP) was positive and the Ki-67 proliferation index was high (60%), suggesting a germ cell tumor. After 3 months of follow-up, neither recurrence of tumor nor complications were found in the patient. The diagnosis of YST should be confirmed on the basis of clinical manifestations, neuroimaging and pathological findings. Gross total resection (GTR) is an ideal treatment for YST. However, due to the location of the tumor, GTR is usually difficult, and the rate of postoperative complications is high. This reported case shows that subtotal resection can be a good treatment strategy for YST.

Multidisciplinary team for the diagnosis and treatment of 2 cases of primary intestinal yolk sac tumor

Extragonadal primary yolk sac tumor of the intestinal tract origin is exceedingly rare. Through a multiple disciplinary team, the diagnosis and treatment of primary intestinal yolk sac tumor were further defined. We report 2 such cases with detailed histologic and immunohistochemical analysis. The two patients were a 7-year-old girl and a 29-year-old woman. Both of them preoperatively had an elevated serum alpha fetoprotein (AFP) level (≥ 1,210 ng/mL). The tumors are located in the intestine and imaging examination indicated the rectum as the primary site. Grossly the mass was grey-white and crisp texture. Microscopic examination featured reticular, microcystic, macrocystic, papillary, solid, and some glandular patterns. Immunohistochemically, tumor cells of both cases were positive for SALL4, AFP, pan-cytokeratin (AE1/AE3), and glypican-3. Simultaneously, a stain for EMA, OCT4, CD30, HCG, vimentin and CK20 were negative in all 2 neoplasms. The features of morphology, immunohistochemistry, laboratory examinations and imaging studies consist of the diagnosis of primary yolk sac tumor of the intestine.

Yolk Sac Tumor in an Eight-Year-Old Girl: A Case Report and Literature Review

Yolk sac tumor (YST), which most frequently arises in the gonads as a type of germ cell tumor, is rare in children but is highly malignant. It has been suggested that alpha-fetoprotein (AFP) can be applied as a feasible tumor marker because its level was elevated in >90% of YST. The treatment generally involves debulking surgery of tumors followed by systemic chemotherapy. Metastasis process of YST in children is different from that in adults and thus the treatment option is required. In this study, we described a rare case of YST in terms of the clinical manifestation, imaging, and histopathology findings, diagnosis and treatment in an 8-year-old girl. Furthermore, it is important to investigate more thoroughly a patient with history of intermittent abdominal pain and fever with previously multiple accesses, because these might be the critical signs for YST that should be alarmed for early treatment. Although YST is rare in children, pediatric physicians should be aware of this and prompt treatment should be addressed.

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.

Primary cerebellar endodermal sinus tumor: A case report

Endodermal sinus tumors are rare malignant germ cell tumors that usually originate from the gonads and are rarely observed extragonadally. Pure primary endodermal sinus tumors of the cerebellar hemisphere are extremely rare and patients diagnosed with the disease often have a poor prognosis. The symptoms of YSTs are unspecific and associated with the location of tumors. Intracranial YSTs (such as cerebellar hemispheres) always present with symptoms including headache and poor vision. The present study reports the case of a three-year-old male who presented to The First Affiliated Hospital of Nanchang University (Nanchang, China) with a headache that had persisted for one month, and then worsened for the last 10 days. This was accompanied by vomiting and gait disturbance. An abnormal signal mass was identified in the left cerebellar hemisphere on brain magnetic resonance imaging. The case initially presented as a medulloblastoma and the patient was followed up for six months. The final pathology report revealed an endodermal sinus tumor, also known as a yolk sac tumor. Six months following resection of the left cerebellar tumor, the patient succumbed to recurrence of the disease, due to acute vomiting and severe headache.