Metaplastic thymoma: A rare and indolent subtype.

Area of Science:

• Oncology
• Pathology
• Thoracic Surgery

Background:

• Thymomas are common anterior mediastinum neoplasms.
• Metaplastic thymoma is an extremely rare subtype with distinct biphasic morphology.
• It was included in the 2004 WHO classification of thymic epithelial tumors.

Purpose of the Study:

• To report a case of incidentally detected metaplastic thymoma.
• To emphasize the histological distinction from other biphasic mediastinal neoplasms.
• To discuss the clinical and pathological features of metaplastic thymoma.

Main Methods:

• Case report of an incidentally detected large mediastinal mass.
• Histopathological examination to identify biphasic morphology.
• Review of literature on metaplastic thymoma.

Main Results:

• The mediastinal mass exhibited features consistent with metaplastic thymoma.
• The tumor demonstrated a benign clinical course.
• Histological differentiation from aggressive biphasic neoplasms was crucial.

Conclusions:

• Metaplastic thymoma is a rare entity requiring careful histological evaluation.
• Accurate diagnosis is essential to guide appropriate patient management.
• This case underscores the importance of recognizing rare thymoma subtypes.