Clinical outcome of thymic lymphoepithelioma-like carcinoma: Case report of a 14-year-old male

Thymic carcinoma is a rare type of cancer, which arises from the thymic epithelium and accounts for ~1-4% of anterior mediastinal tumors in the USA. It rarely occurs in children, and is rarer among adults. Thymic lymphoepithelioma-like carcinoma (LELC) is an uncommon subtype of thymic carcinoma in children, however, it is one of the common histological subtypes of thymic carcinoma in adults. In the present study, a 14-year-old male patient presented to the Tokyo Metropolitan Cancer and Infectious diseases Center, Komagome Hospital (Tokoyo, Japan) with chest pain due to a large anterior mediastinal mass. The patient was histologically diagnosed with thymic LELC via a needle biopsy specimen, which was obtained from the primary site and indicated the Epstein-Barr virus infection, whose markers are also associated with oncogenesis. Immunohistochemical analysis demonstrated positive staining for keratin (AE1/AE3), epithelial membrane antigen, and latent membrane protein-1 and negative staining for cluster of differentiation 5. Thus, the patient was diagnosed with metastatic thymic LELC. First-line chemotherapy comprising of a cisplatin- and adriamycin-based chemotherapy regimen achieved a partial response, however, the patient succumbed within 10 months of the initial diagnosis due to rapid disease progression and refractory to subsequent cycles of chemotherapy. Thus, the current study, as well as previously reported cases, demonstrates that pediatric patients with thymic LELC continue to have a poor prognosis.