Thymic Cysts: A Rare Entity in Adults

Multilocular thymic cysts can be easily misdiagnosed as malignant tumor on computer tomography: A case report

BACKGROUND

Multilocular thymic cyst (MTC) is a rare mediastinal lesion which is considered to occur in the process of acquired inflammation. It is usually characterized by well-defined cystic density and is filled with transparent liquid.

CASE SUMMARY

We report on a 39-year-old male with a cystic-solid mass in the anterior mediastinum. Computer tomography (CT) imaging showed that the mass was irregular with unclear boundaries. After injection of contrast agent, there was a slight enhancement of stripes and nodules. According to CT findings, it was diagnosed as thymic cancer.

CONCLUSION

After surgery, MTC accompanied by bleeding and infection was confirmed by pathological examination. The main lesson of this case was that malignant thymic tumor and MTC of the anterior mediastinum sometimes exhibit similar CT findings. Caution is necessary in clinical work to avoid misdiagnosis.

Adult Cervical Thymic Cysts: A Narrative Review

OBJECTIVE

Thymic cysts are rare benign neck masses, accounting for less than 1% of all cervical masses. This study aims to discern different presentations, investigations, and treatment options of thymic cysts in adults by reviewing prior published studies from January 2010 to October 2021 to bridge the knowledge gap since the last review by Michalopoulos in 2011. Moreover, we present a case of a 28-year-old male with a left cervical thymic cyst.

DATA SOURCES

Data were obtained from a literature search using the ScienceDirect, PubMed, ResearchGate, and Google Scholar databases.

METHODS AND RESULTS

This study retrospectively analyzes reported cases of adult cervical thymic cysts by collecting demographic data, patient presentation, duration, location, size, type of imaging, fine-needle aspiration, and surgical approach. Eighteen patients were included. Cysts were seen on the left (n = 9), right (n = 5), and midline (n = 4). The age of the patients ranged from 19 to 64 years. Most patients present with painless left-sided neck swelling. Computed tomography (CT) was the preferred imaging modality in most cases. Moreover, surgical excision was essential for therapeutic and diagnostic purposes. This study did not require institutional review board approval.

CONCLUSION

Adult cervical thymic cyst is a rare etiology. Nevertheless, a painless left-sided neck mass with no clear lower border should uphold thymic cyst as a differential diagnosis. MRI and CT scans are the preferred imaging modalities for preoperative planning. Surgical excision is mandatory for treatment and histological confirmation. As of October 2021, around 54 cases of adult thymus cysts had been reported to the best of our knowledge and review.