Mediastinal seminoma associated with multilocular thymic cyst

Area of Science:

• Oncology
• Thoracic Surgery
• Pathology

Background:

• Anterior mediastinal masses can present diagnostic challenges, with thymoma and lymphoma being common considerations.
• Seminoma, a germ cell tumor, is typically found in the testes but can rarely occur in the mediastinum.
• Multilocular thymic cysts are benign lesions that can be associated with thymic neoplasms.

Purpose of the Study:

• To report a rare case of primary mediastinal seminoma coexisting with multilocular thymic cysts.
• To describe the diagnostic and therapeutic approach for this unusual presentation.
• To highlight the importance of comprehensive staging and adjuvant therapy.

Main Methods:

• Computed tomography (CT) and 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scans for diagnosis and staging.
• Surgical resection via median sternotomy for tumor removal.
• Adjuvant chemotherapy with bleomycin, etoposide, and cisplatin (BEP) regimen.

Main Results:

• Pathological examination confirmed primary mediastinal seminoma with coexisting multilocular thymic cysts.
• Postoperative staging revealed no evidence of distant metastasis, except for an abnormal uptake in a mesenteric lymph node on FDG-PET.
• Adjuvant BEP chemotherapy resulted in complete resolution of the mesenteric lymph node uptake.
• No recurrence or metastasis observed during 16 months of follow-up.

Conclusions:

• Primary mediastinal seminoma can rarely present with coexisting thymic cysts, which may represent secondary changes.
• Multimodality treatment including surgery and adjuvant chemotherapy is effective in managing this rare condition.
• Close follow-up with imaging is crucial to monitor for recurrence or metastasis.