Ossifying thymoma clinically presenting with peripheral T-cell lymphocytosis

Area of Science:

• Oncology
• Pathology

Background:

• Ossifying thymoma is an extremely rare tumor, with only one previous case reported in English literature.
• Thymomas are neoplasms originating from the thymus gland, often found in the anterior mediastinum.

Observation:

• A 62-year-old woman was incidentally diagnosed with an anterior mediastinal tumor.
• The tumor was histopathologically confirmed as a type B1 thymoma exhibiting stromal ossification.
• The patient also presented with a peculiar finding of peripheral T-cell lymphocytosis.

Findings:

• This case represents the second reported instance of ossifying thymoma in the English literature.
• Surgical resection of the thymoma was performed 42 months after initial detection.
• The patient has shown no signs of disease recurrence 50 months after surgical removal.

Implications:

• This case expands the understanding of rare thymoma variants and their presentations.
• The co-occurrence of peripheral T-cell lymphocytosis warrants further investigation in thymoma patients.
• Long-term follow-up confirms favorable outcomes after resection of this rare ossifying thymoma variant.