Discussion
Thymolipomas, a type of mediastinal tumor that consists of mature adipose and thymic tissue, are exceedingly rare and arise in the thymus gland. They make up 1.1% of all solid mediastinal tumors and do not exhibit any gender preferences (3). Thymolipomas are characterized by the presence of abundant mature fat, which separates the thymic tissue component, with no evidence of atypia or mitotic activity. Although most of these tumors are clinically quiescent, they can grow to significant sizes and present clinical symptoms such as compression of the lower respiratory tree, resulting in breathlessness, coughing, chest discomfort, and upper respiratory tract infection. (2) Furthermore, it can lead to cardiac compression and subsequently, chronic heart failure. (4) The radiologic characteristics have the ability to resemble various conditions, such as cardiomegaly, pericardial effusion, pleural tumors, pericardial tumors, and basal atelectasis (5, 6).
Thymolipoma has been found to have associations with chronic lymphocytic leukemia, myasthenia gravis, aplastic anemia, hyperthyroidism, and Hodgkin’s disease in certain cases (7). In our scenario, there was no relationship established between this presenting case and the tumors mentioned earlier.
The CT scan is typically the preferred diagnostic modality. The consideration of thymolipoma diagnosis should be taken into account when evaluating the accuracy of an anterior mediastinal mass characterized by fatty tissue containing soft tissue streaks, which signify islands of normal thymic components, along with contralateral displacement of the mediastinum on CT scans. (8, 9) A similar finding was observed in the CT scan outlined in this case report. Teratoma, lipoma, lipomatosis, and liposarcoma are potential differential diagnoses that should be considered. (3) There have been reported cases of thymolipoma in different age groups. (1, 2, 6, 8, 9, 10) Thymolipomas, although uncommon, should be included in the differential diagnosis, even in cases of infants with an anterior mediastinal mass. A case of this type of tumor occurring in a 6-month-old boy has been reported. (11) Thymic tumors, specifically thymoma, are rarely found outside the mediastinum (12, 13), but the occurrence of thymolipoma in the lung or other mediastinal structures, excluding the thymus, has not been recorded. The considerable dimensions of the tumor in our patient presented considerable obstacles in determining the precise location or origin of the mass before the operation.
Surgical excision is the recommended treatment for thymolipoma, as it is curative and eliminates the need for long-term follow-up for a benign tumor. No cases of recurrence, metastasis, or mortality have been reported.