Extragonadal Yolk Sac Tumor Research Articles

Primary extragonadal yolk sac tumor of the orbit: A rare case and review of literature

Germ cell tumors usually arise from primordial cells in gonads, mainly testes, and ovaries. Extragonadal involvement of orbit is very unusual. We report one case of primary yolk sac tumor of orbit in a 3-year-old male child presented as a left lateral orbital mass. Its clinical presentation may mimic many common pediatric orbital tumors causing misdiagnosis which affects ocular morbidity and mortality. Awareness about this rare entity to clinicians is helpful in the early diagnosis and proper management of young kids.

Clinical characteristics and prognostic models of gonadal and extra-gonadal yolk sac tumors: a population-based analysis in children and adolescents.

Yolk sac tumors (YST) are a rare and aggressive germ cell tumor. We aimed to conduct a population-based cohort study and develop a nomogram to predict overall survival (OS) in pediatric patients with YST. The Surveillance, Epidemiology, and End Results (SEER) database was used to identify all pediatric patients with YST diagnosed between 2000 and 2018. The log-rank test was used to compare survival curves. To examine the impact of each factor on overall survival, a multivariate Cox proportional hazards model was created. Based on the results of the Cox regression model, a nomogram was constructed. A total of 520 YST patients were identified. Overall survival rates for all patients were 92.2% at 3-year and 90.3% at 5-year, respectively. The outcome of Cox proportional hazard regression revealed that age, gender, primary sites, and treatment regimens were important independent predictors in this model. Based on the Cox regression model, we created a nomogram for predicting OS in pediatric YST patients. The chance of death increased with age in patients. Furthermore, patients with extra-gonadal YST have a lower survival rate than those with gonadal YST. Our study revealed that age, gender, and primary site were found to be the most important predictors of the overall survival of pediatric YST, providing crucial epidemiological information for clinical management.

Primary Esophageal Extra-Gonadal Yolk Sac Tumor Metastasized to the Liver

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Preservation of sexual and reproductive function in the treatment of extragonadal yolk sac tumors in the female genital tract.

This study aimed to summarize the clinical features, treatment modalities, therapeutic effects, menstruation and fertility outcomes, and prognosis of extragonadal yolk sac tumors (YSTs) of the female genital tract. We reviewed 32 cases of extragonadal YSTs in the genital tract treated between 1983 and 2021. The medical records, including clinical characteristics, histopathology, treatments, chemo-reduced adverse events, and outcomes on long-term follow-up, were collected. Among the 32 cases, 30 were vaginal YSTs and two were uterine YSTs (endometrial and cervical). Thirty patients (30/32, 93.8%) were <4 years. Abnormal vaginal bleeding (n = 31) and elevated serum alpha-fetoprotein level (n = 32) were the most common presentations. Vaginohysteroscopy and/or pediatric rhinoscopy were used for diagnosis in 17 pediatric patients and evaluation of chemotherapeutic efficacy in 21 pediatric patients. All the patients received combination chemotherapy. Bleomycin/etoposide/cisplatin (BEP) was chosen with prior consideration in 28 cases; 21 patients were treated with BEP alone. Yellow or grayish-yellow tissue with irregular shape was found in 66.7% of the cases during repeat examinations. Five patients underwent surgeries during repeat examinations and follow-ups, and no evidence of malignancy was noted in them. Thirty-one patients achieved complete remission. During a median follow-up of 63 months (2.4-240.3 months), two patients experienced recurrence, three died, and 29 remained disease-free. One patient recovered menstruation and five had undergone menarche. BEP chemotherapy can serve as a preferred treatment modality for vaginal and uterine YSTs. Vaginohysteroscopy and pediatric rhinoscopy can be used for diagnosis and evaluation of chemotherapeutic efficacy in pediatric patients. YSTs possibly appear as yellow or grayish-yellow after chemotherapy.

A Rare Case of Metastatic Extragonadal Yolk Sac Tumor – A Challenging Diagnosis on Cytomorphology

Abstract Introduction/Objective Yolk sac tumors are characterized by variable histologic patterns and broad cytologic spectrum; thereby making the distinction from a poorly differentiated adenocarcinoma in a metastatic site extremely challenging. We present cytology and histology of a metastatic extragonadal germ cell tumor with predominant solid yolk sac component. Methods/Case Report 36-year-old male presented with bilateral supraclavicular masses (right: 6 x 7 cm, left: 3 x 4 cm). CT chest and abdomen revealed large mediastinal and hilar nodal mass (11.6 cm), right hilar mass (8.5 cm), bilateral heterogeneous adrenal masses (right: 11.4 cm, left: 3.1 cm), and an enhancing retroperitoneal implant. Differential diagnoses of lymphoma, adrenocortical carcinoma, small cell lung carcinoma, and metastatic germ cell tumor were considered. Testicular ultrasound revealed no masses. Fine needle aspiration of supraclavicular lymph nodes showed highly cellular smears comprised of tumor cells, dispersed singly and in clusters, with irregular nuclear contours, increased nuclear to cytoplasmic ratio, coarse chromatin, occasional prominent nucleoli, and vacuolated cytoplasm. Tumor cells were positive for KRT7 and TTF-1, and negative for p40 and PAX8. A diagnosis of metastatic poorly differentiated carcinoma was rendered. Subsequent excisional biopsy of the lymph node showed a metastatic tumor with tumor cells similar to those seen in cytology, appearing in solid sheets with focal papillary architecture, replacing the entire lymph node. Additional immunohistochemistry showed expression of SALL4, Glypican 3, with lack of expression for OCT3/4, AFP, hCG, and CD30, supporting the diagnosis of metastatic yolk sac tumor, solid pattern. Results (if a Case Study enter NA) NA. Conclusion Aggressive clinical presentation, broad clinical differential diagnoses, rarity of a primary mediastinal yolk sac tumor, non-diagnostic cytomorphology along with expression of divergent differentiation markers (TTF-1 in our case) makes a definitive diagnosis of metastatic extragonadal yolk sac tumor extremely challenging. High index of clinical suspicion is required for a definitive diagnosis on cytomorphology.

An Extremely Rare Case of a Primary Pancreatic Yolk Sac Tumor

Yolk sac tumor (YST) is a rare malignant type of germ cell tumor (GCT). Extragonadal yolk sac tumor is a very rare entity. We report the case of a 33-year-old male with a pancreatic mass, which proved to be a primary yolk sac tumor, arising in the pancreas.

Urachal yolk sac tumor penetrating the bladder as a diagnostic challenge: a case report and review of the literature

BackgroundYolk sac tumor (YST) is a germ cell tumor. It is primarily located in the gonads but can also occur extragonadally (extragonadal yolk sac tumor - EGYST), most commonly in the pelvis, retroperitoneum or mediastinum. Only a few YSTs of the urachus have been described.Case reportWe present a rare case report of a 37-year-old male with episodes of macroscopic hematuria. The histological specimen obtained by transurethral resection showed a solid, and in some parts papillary infiltrative, high-grade tumor with numerous areas of marked nuclear atypia and clear invasion between the detrusor bundles. Glandular pattern has been observed in only minority of the tumor. Immunohistochemistry showed significant positivity for GPC3, SALL4 and cytokeratins AE1/AE3, while KRT7 and GATA3 were negative. We concluded that the biopsy findings were consistent with urothelial carcinoma with infrequent YST differentiation. In definitive surgical specimens we found a malignant epithelial, glandular and cystically arranged tumor of germinal appearance arising from urachus. The surrounding urothelium was free of invasive or in situ tumor changes. We reclassified the tumor as a urachal YST.ConclusionEGYST was suspected because glandular and hepatoid structures were found, but the presence of these structures should be verified by immunohistochemistry.

Extragonadal Yolk Sac Tumor with Spinal Cord Compression in a Little Boy, with Complete Response to the Bleomycin, Etoposide, and Carboplatin: A Case Report and Review of the Literature

Introduction: Germ cell tumors account for 3.5 % of pediatric tumors and yolk sac tumors are the most common pure malignant germ cell tumors in children. Testis and ovary are the most common sites of involvement in children older than 2 years. Case Presentation: A 20-month-old boy with a complaint of limping was described in this case report. Abdominal ultrasonography showed a 52 × 50 mm solid abdominal mass. Abdominal and pelvic computed tomography scans showed a left paraspinal heterogeneous mass. The tumor was extended into the spinal column with spinal cord compression. Four months later, at the end of chemotherapy, the tumor was completely resolved. Conclusions: Spinal cord compression is a rare presentation of yolk sac tumor (YST) and although this tumor is an uncommon malignancy, it can be cured completely.

27. A Case of Vaginal Yolk Sac Tumor in an 8 Year Old Girl with Didelphys Uterus

<h3>Background</h3> Vaginal yolk sac tumors are quite rare in children. They usually occur in young girls under the age of 3 and present with vaginal bleeding. We present a case where an initial exam under anesthesia revealed no evidence of a vaginal malignancy. However, due to ongoing symptoms, a re-evaluation revealed vaginal yolk sac tumor which had been concealed by a congenital anomaly. <h3>Case</h3> An 8 year old girl presented with a 3 month history of pre-pubertal vaginal bleeding. A workup revealed pre-pubertal hormonal levels, no evidence of vaginal infections or foreign objects and no concerns for sexual abuse. Imaging revealed a didelphys uterus with 2 cervixes and a 9mm collection of heterogeneous material which appeared to be within an obstructed left hemi-vagina. On vaginoscopy there was no visible blood, no distension of the left hemi-vagina that could be visualized, and no evidence of malignancy. Due to ongoing symptoms, exam under anesthesia was repeated in one year. On this exam a bulge was noted in the vagina. The vaginal septum was perforated and significant vaginal tumor was discovered within the left hemi-vagina. This was biopsied and found to be an extra-gonadal yolk sac tumor. She was subsequently referred to oncology and diagnosed with Stage III extra-gonadal yolk sac tumor with negative AFP. She received 4 cycles of cisplatin, bleomycin and etoposide (PEB). She underwent interval debulking of vaginal tumor, which was halted due to excessive bleeding from the tumor. She underwent 2 additional cycles of PEB followed by excision of the vaginal septum. At that time there was no further visible tumor and no tumor was identified on histologic evaluation of the septum. <h3>Comments</h3> This case illustrates difficulty diagnosing a vaginal tumor due to a congenital anomaly. It is critical to continue to follow patients with pre-pubertal bleeding if there is no etiology discovered initially. Though malignancy is a rare cause of pre-pubertal vaginal bleeding, it is important to reconsider this in cases which include congenital anomalies that may delay the diagnosis.

A Rare Case of Metastatic Spinal Cord Compression Originating from Extragonadal Mediastinal Yolk Sac Tumor: A Case Report

Spinal metastases of nonseminomatous germ cell tumor (NSGCT) found in extragonadal location is a rare event and even more uncommon at the initial presentation. In this case report, we present a 20-year old male’s clinical presentation of spinal cord compression. He presented with paraplegia, neurologic bladder, and bowel dysfunction. Spinal Magnetic Resonance Imaging (MRI) demonstrated 9th thoracic vertebra metastasis, and cord compression with edema. A chest computed tomography scan with contrast further revealed mediastinal and right infrahilar mass. Its histopathological features were consistent with Yolk Sac Tumor (YST). Further investigation using bone scintigraphy revealed spinal metastasis. This case represents a rare clinical presentation and disease manifestation of a metastatic extragonadal YST originating from the mediastinum and causing spinal cord compression in an adult male. Although it is rare, spinal cord compression should raise awareness and prompt evaluation for metastatic lesions given the rate of NSGCT metastasis and its associated poor prognosis.

Primary Extragonadal Yolk Sac Tumor Arising from the Urachus: A Case Report with Literature Review

Primary Extragonadal Yolk Sac Tumor Arising from the Urachus: A Case Report with Literature Review

Hepatoid Adenocarcinoma of the Rectum With Liver Metastasis in Patient With Ulcerative Colitis

Hepatoid adenocarcinoma (HA) is a rare malignant tumor of extrahepatic origin that morphologically and immunophenotypically resembles hepatocellular carcinoma. We report a case of a 38-year-old Caucasian male with 13 year history of ulcerative colitis who initially presented to an outside facility with three months of diarrhea, mild abdominal pain, and ten-pound weight loss. Outpatient colonoscopy revealed severely ulcerated rectosigmoid mucosa with necrotic features and he was transferred to our facility for further workup of presumed ischemic colitis. CT abdomen showed a large, 8.1 x 9.4 x 6.6 cm hepatic mass with portal vein thrombus and rectosigmoid thickening. Liver protocol MRI did not demonstrate characteristic contrast washout seen in hepatocellular carcinoma (HCC). Alpha-feto protein (AFP; 15,523 ng/mL) and carcinoembryonic antigen (CEA; 20.3 ng/mL) were elevated. The patient subsequently underwent triple phase CT which was also not consistent with HCC. Scrotal ultrasound to rule out a primary testicular malignancy was negative; however, human chorionic gonadotropin (beta hCG) was elevated, increasing the concern for extragonadal yolk sac tumor. The patient underwent liver biopsy and repeat colonoscopy with rectal biopsies. Histologic morphology and immunophenotype from both specimens were consistent with hepatoid adenocarcinoma. Given these findings a diagnosis of hepatoid adenocarcinoma of the rectum with hepatic metastasis was made. The patient was subsequently started on palliative FOLFOX chemotherapy. Hepatoid adenocarcinoma is a rare malignant tumor of extrahepatic origin whose features mimic those of hepatocellular carcinoma. Most cases have been reported as arising in the stomach, though HA has also been described in the small and large intestines, lung, ovary, uterus, bladder, pancreas, and gallbladder. HA is often metastatic at time of diagnosis and carries a poor prognosis. Most cases of HA arising in the intestines have been described in patients with inflammatory bowel disease, who are known to be at increased risk of developing adenocarcinoma of the GI tract. Hepatoid adenocarcinoma should be considered in the differential diagnosis of malignant lesions in the IBD patient.Figure: A. A liver core biopsy low power image depicting diffuse infiltration of the tissue by carcinoma. B &C. High power images reveal a mixed hepatocellular/trabecular and glandular architecture composed of cytologically atypical eosinophilic cells vaguely resembling atypical hepatocytes. Immunohistochemistry (not shown) exhibits positive staining for pankeratin, cdx-2, polyclonal CEA, monoclonal CEA, alpha-fetoprotein, glypican-3, SALL-4, and focal positivity for CK20, and is negative for CK7, HepPar-1, Vimentin, CD31, and CD34.

ZBTB16 is a sensitive and specific marker in detection of metastatic and extragonadal yolk sac tumour.

Accurate histological diagnosis and classification of germ cell tumours (GCTs) is key to informing successful therapeutic and surveillance strategy. The modern therapeutic approach for yolk sac tumour (YST) is highly curative. Because YST takes on a large morphological spectrum, it can be confused for other GCT subtypes as well as somatic carcinomas, particularly when YST presents in an extragonadal or a metastatic setting. Currently available immunohistochemical markers are limited by suboptimal sensitivity and specificity. We reported recently that ZBTB16 is a sensitive and specific marker for testicular YST. ZBTB16 is absent in other GCTs and in most common somatic carcinomas, including those of gastrointestinal, pancreatobillary, respiratory, genitourinary and gynaecological tracts. The purpose of this study is to investigate the diagnostic utility of ZBTB16 in the settings of metastatic and extragonadal YST. We studied 32 archived metastatic and four extragonadal primary YSTs as well as 51 somatic malignancies for their immunohistochemical expression of ZBTB16. For comparison, α-fetoprotein (AFP) and glypican-3 were also studied in parallel. Our results demonstrated an overall sensitivity of 91.6% for ZBTB16 in detecting metastatic and extragonadal YSTs. The non-YST elements (teratoma and embryonal carcinoma) in 15 YST-containing metastatic mixed GCTs were non-reactive. With the exception of occasional myoepithelial cells of salivary gland carcinoma, all the 51 somatic malignancies were negative for ZBTB16. ZBTB16 is a sensitive and specific marker for YST and is diagnostically superior to AFP and glypican-3 in metastatic and extragonadal settings.

RETROPERITONEAL PRIMARY YOLK SAC TUMOUR IN ADULT MALE

Yolk sac tumour also called as endodermal sinus tumour is a malignant germ cell tumour. Extra gonadal germ cell tumours are very rare. The most common extra gonadal site is mediastinum. Retroperitoneum is the second most common site of occurence. We report a case of a primary extragonadal yolk sac tumour in an adult male who presented with abdominal pain, Imaging showed a very large retroperitoneal mass. Histopathology of the biopsied specimen showed it as a Yolksac tumour.

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.

Diagnostic and therapeutic challenges in extragonadal yolk sac tumor with hepatoid differentiation: A case report.

Yolk sac tumors (YSTs) are rare aggressive tumors, arising most commonly in the gonads and occurring mainly in young adults. We herein report a case of an extragonadal YST with hepatoid differentiation localized in the brain and lung. A 41-year old man presented to our hospital with a generalized seizure. A head computed tomography and magnetic resonance imaging examination revealed a large mass in the left occipital lobe with associated edema. Following complete resection, the histopathological examination revealed that the mass was a highly malignant epithelial tumor with a hepatoid pattern. The serum lactate dehydrogenase and α-fetoprotein levels were elevated. Additional diagnostic imaging revealed a lesion in the upper lobe of the right lung, but no other tumor manifestations. Based on the clinical and immunohistochemical characteristics, hepatocellular carcinoma and hepatoid adenocarcinoma were excluded and the diagnosis of extragonadal hepatoid YST was established. A multimodal therapeutic approach (high-dose chemotherapy with autologous stem cell transplantation, radiation and surgery) was applied; however, the patient succumbed to refractory disease 10 months after the diagnosis. Therefore, the diagnosis and treatment of hepatoid YST is an interdisciplinary challenge.

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.

High-level expression of divergent endodermal lineage markers in gonadal and extra-gonadal yolk sac tumors

AbstractYolk sac tumors occur at both gonadal and extra-gonadal sites. A recent case of ovarian endometrioid-pattern yolk sac tumor with strong diffuse expression of TTF-1 illustrated the potential for misdiagnosis due to divergent expression of endodermal lineage markers. The aim of this study was to investigate the expression of four divergent endodermal lineage markers, TTF-1, CDX2, Hep Par 1, and Napsin A, in gonadal and extra-gonadal yolk sac tumors of differing age, sex, and location (excluding foci of overt hepatoid differentiation). We identified 26 cases (5 ovarian, 15 testicular, and 6 extra-gonadal) containing yolk sac tumor as identified by typical histology and confirmed by positive immunohistochemical staining for alpha-fetoprotein and glypican-3. Mixed or ambiguous foci were confirmed by immunohistochemistry (SALL4 positive and Oct-4 negative). The relative proportion of three histologic patterns: reticular/cystic, solid/myxoid, and glandular was estimated. Percent positivity for the four divergent endodermal lineage markers was compared within yolk sac tumor areas according to site, age group, and histologic pattern. High-level (>25%) staining for one or more divergent endodermal lineage markers was seen in eleven cases: Hep Par 1 in seven cases, all post-pubertal, TTF-1 in four cases, two ovarian and two extra-gonadal, and CDX2 in three cases, with no age or site predilection. No case highly expressed all three divergent endodermal lineage markers, but four co-expressed high levels of two markers: two ovarian yolk sac tumors with TTF-1 and Hep Par 1, one testicular yolk sac tumor with CDX2 and Hep Par 1, and one extra-gonadal yolk sac tumors with TTF-1 and CDX2. While no absolute correlation of high-level divergent endodermal lineage marker expression with histologic subtype was observed, TTF-1 and CDX2 expression was predominantly seen in reticular/cystic and glandular areas while Hep Par 1 was most frequent in myxoid/solid and glandular areas.

Extragonadal yolk sac tumor (endodermal sinus tumor) presenting with biliary tract obstruction in a woman

A 35-year-old woman presented to her primary care physician with early satiety, weight loss, nausea, vomiting, and pruritus. She was eventually found to have a pancreatic mass obstructing the bile duct. The mass was evaluated by endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasonography (EUS) with biopsy. Histopathology results revealed a high grade malignant neoplasm of uncertain type. The tumor was further characterized by open biopsy, which revealed a yolk sac tumor (endodermal sinus tumor). Her disease was unresectable. Serum alpha-fetoprotein (AFP) levels were markedly elevated (693.3 ng/ml; reference range: 0-8 ng/ml). The patient was treated with bleomycin, etoposide, and cisplatin (BEP) with a partial response and a persistently elevated serum AFP of 139.7 ng/ml. She then received salvage chemotherapy with paclitaxel, ifosfamide, and cisplatin (TIP), with a minimal response (serum AFP, 68 ng/ml). She next received an autologous bone marrow transplant, with a decline in AFP to 19 ng/ml after the first of two tandem transplants. This case report illustrates a rare presentation of an extragonadal endodermal sinus tumor in a woman with biliary tract obstruction as the predominant manifestation.

Extragonadal germ cell tumor (yolk sac tumor) arising in a case of familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant condition that results in development of the large number of colorectal, and eventually, small intestinal or even gastric adenomas at an early age (late childhood to early adulthood). Extragonadal yolk sac tumors (YSTs) of the gastrointestinal tract are extremely rare neoplasms. Their greater rarity compared with other extragonadal YSTs suggests that different pathogenetic mechanisms could be involved according to the site of origin. Recent epigenetic studies suggest the involvement of some tumor suppressor genes, including the adenomatous polyposis coli gene in testicular YST. No case has so far been described in setting of FAP. Hereby, we describe a case of extragonadal germ cell tumor arising in colectomy stump of a patient with FAP.