摘要
Abstract
Objective:Primary mediastinal yolk sac tumor(PMYST)is a rare malignancy characterized by high-grade malignancy,rapid progression,and poor prognosis.This study aims to explore the clinical and pathological characteristics,diagnostic criteria,differential diagnosis,treatment strategies,and prognosis of primary mediastinal yolk sac tumor(PMYST).
Methods:A retrospective analysis was conducted on the clinical,pathological,immunophenotypic characteristics,and morphology,immunophenotype,and tumor biological behavior of 6 cases of PMYST,accompanied by a literature review.
Results:All 6 patients were male,with an onset aged 15 to 53 years(average age:30 years).Serum alpha-fetoprotein(AFP)levels were significantly elevated in all cases.Chest CT scans revealed anterior-middle,anterior-right,or anterior mediastinal soft tissue masses,with a maximum tumor diameter ranging from 6 to 17 cm(mean:12 cm).Histopathology showed loose reticular,papillary,or glandular structures with characteristic Schiller-Duval bodies.Immunohistochemistry revealed positivity for AFP,spalt-like transcription factor 4(SALL4),pan-cytokeratin(CK-pan),placental alkaline phosphatase(PLAP),and Glypican-3 in all 6 cases,with focal positivity for CK-pan and AFP in 1 case each,and focal PLAP positivity in 3 cases.One case was positive for vimentin,and 1 showed weak CD117 positivity.All cases were negative for CD30,octamer-binding transcription factor 3/4(OCT3/4),and epithelial membrane antigen(EMA).The Ki-67 proliferation index ranged from 80%to 90%.Among the 6 cases,4 underwent biopsy,with 1 subsequently receiving surgical resection post-treatment,and 2 underwent direct surgical resection.All 6 cases were diagnosed as yolk sac tumors,with 2 cases showing mixed seminoma components.All patients received chemotherapy(BEP or EP regimens),and 2 also underwent radiotherapy.Follow-up ranged from 7 to 36 months:Four patients died,1developed pulmonary metastasis,and 1 showed no recurrence or metastasis.
Conclusion:PMYST predominantly affects young male patients and is highly malignant with a low survival rate.Imaging findings of mediastinal mass along with elevated serum AFP levels can aid diagnosis,which is confirmed by pathological examination.Postoperative chemotherapy using BEP or EP regimens is the mainstay of treatment,and serum AFP is a valuable prognostic biomarker.关键词
卵黄囊瘤/纵隔/青年男性/病理学特征/临床表现Key words
yolk sac tumor/mediastinum/young males/pathological features/clinical presentation
