Intrathyroid thymic carcinoma (ITTC) is an exceptionally rare primary thyroid malignancy with thymic epithelial differentiation, generally characterized by relatively indolent biological behavior. However, significant knowledge gaps persist in ITTC diagnosis, and a consensus on an optimal treatment strategy for ITTC is lacking. This review synthesizes the current knowledge on ITTC, focusing on its clinicopathological features, molecular landscape, prognostic factors, and therapeutic approaches, to raise clinical awareness of this rare entity and guide individualized management. ITTC predominantly affects adults, with a slight female predilection. Pretreatment diagnosis in imaging and cytology of ITTC is challenging. Histopathologically, ITTC is indistinguishable from thymic squamous cell carcinoma (TSCC), and no specific molecular alterations have been identified to date. Lymph node metastasis and the presence of symptoms at diagnosis serve as adverse prognostic indicators in ITTC patients. While surgery remains the priority treatment for ITTC, patients' responses to adjuvant radiotherapy and/or chemotherapy are variable, underscoring the need for further investigation into the role of systemic antineoplastic therapies. Notably, checkpoint inhibitors targeting PD-L1 or PD-1 represent a promising avenue for ITTC patients with advanced disease.
Gao et al. (Fri,) studied this question.