Mucoepidermoid carcinoma of the thymus: a case report

Mucoepidermoid carcinoma of the thymus incidentally diagnosed following two-years of non-productive cough

Mucoepidermoid carcinoma of the thymus is a rare primary thymic carcinoma. Radiologic imaging of this malignancy is rarely reported in literature. We present a patient who complained of a chronic cough for two years who was later found to have mucoepidermoid carcinoma of the thymus. Chest radiograph revealed a large anterior mediastinal mass. Follow-up computed tomography of the thorax demonstrated a large, heterogeneous anterior mediastinal mass with traversing vessels. F-18 fluorodeoxyglucose positron emission tomography-computed tomography demonstrated high avidity in the lesion with areas of diminished activity thought to represent necrosis. Following surgical resection, pathology revealed high-grade mucoepidermoid carcinoma of the thymus extending into the skeletal muscle and pericardium with evidence of lymphovascular invasion. The patient received external beam radiation therapy and has remained disease-free for three years.

Thymic Mucoepidermoid Carcinoma: A Systematic Review and Meta-analysis

Thymic mucoepidermoid carcinoma is a rare tumor that remains poorly characterized and a diagnostic challenge. The aim of this review is to characterize this tumor in a larger cohort of patients using all the available cases in the literature. We systematically searched the PubMed and Scopus database for primary thymic mucoepidermoid carcinoma. A total of 24 studies were included in the final analysis. A total of 41 patients were identified; 23 (56.1%) were male and 18 (43.9%) were female. Mean age was 49.8±21.3 years. Mean tumor size was 7.6±3.5 cm. Twenty (66.7%) were low grade and 8 (26.7%) were high grade. In total, 20 (55.6%) patients were treated with surgery alone. Nodal dissection was performed in 4 cases only. Two patients had MAML2 gene rearrangement and 2 were negative. Follow-up time varied from 2 to 93 months. A total of 13 (44.8%) patients died of disease with a median survival of 12 months. There seems to be a bimodal age distribution with peaks between second and third decades of life, and between sixth and eight decades. Lymph node sampling is frequently not performed; however, we recommend performing it, as it may lead to more accurate staging. There is limited data regarding the utility of MAML2 gene rearrangement in the thymic location. Histologic grade and tumor stage/resectability are the main prognostic factors.

Primary Salivary Gland Type Tumors of the Thymus

The existence of primary salivary gland type tumors (SGTs), similar to those occurring in the major salivary glands, is well known in the thoracic cavity. When they occur in this anatomic area, these tumors more commonly arise from the lung. However, the existence of these tumors primarily affecting the thymus, although recognized in the literature, is rather not well documented or known. In addition, contrary to the primary lung SGTs, which are predominantly of the malignant type, these tumors when occur in thymus encompass a wider spectrum of biology ranging from benign to low grade, and high grade malignancy. The recognition of SGTs in the thymus, even though rare, is important to properly address treatment and prognosis. Herein, we will discuss the numerous benign a malignant SGTs that have been described in the thymus and highlight the difficulty that these tumors may pose when occurring in the thymic area.

Primary mucoepidermoid carcinoma of the thymus presenting with myasthenia gravis

Mucoepidermoid carcinoma (MEC) of the thymus is a rare malignant neoplasm of the anterior mediastinum. There are less than 30 cases described in the English literature. We report a case of a 47-year-old lady who presented with myasthenia gravis and was found to have a well-circumscribed anterior mediastinal mass in her medical work-up. This mass was surgically resected and subsequently found to be a primary MEC of the thymus. This is the first reported case of thymic MEC with concurrent myasthenia gravis. Her myasthenia symptoms have persisted following complete surgical resection of her tumour.

Robot-assisted removal of a posterior pharyngeal wall mucoepidermoid carcinoma

This report presents a rare case of a mucoepidermoid carcinoma of the posterior pharyngeal wall of the hypopharynx. Excision of the lesion was performed by transoral robotic surgery (TORS). The rarity of hypopharyngeal mucoepidermoid carcinoma and the technical advantages of TORS are presented and discussed in this study.

Unusual combined thymic mucoepidermoid carcinoma and thymoma: a case report and review of literature

BACKGROUND

In rare condition, combined thymic epithelial tumors showing either type A or type B thymomas areas combined with thymic carcinoma components may occur in thymus. Mucoepidermoid carcinoma (MEC) of the thymus is rare in thymic carcinoma, and so far there is no report to describe a combined epithelial tumor of thymus with MEC component. We report an unusual case of combined thymic MEC/type B2 thymoma in a middle-aged male occurring in a mass of anterior mediastinum.

CASE REPORT

A 51-year-old Chinese male patient presented with a 6-month history of right ptosis and progressive muscle weakness. Computed tomography (CT) examination revealed a solitary, well-circumscribed mass was in the anterior mediastinum with mild heterogeneous enhancement. Histologically, the mass contained two separated components and displayed typically histological features of low-grade MEC and type B2 thymoma, respectively. There was no gradual transition of these two components observed in mass, and no enlarged lymph node was found in the surrounding tissues. A diagnosis of combined thymic MEC/type B2 thymoma was made. The patient received thymectomy to resect the mass totally. After surgery, chemotherapy with regiments of cisplatin and mitomycin, and radiotherapy of the main tumor bed were performed on the patient. There was no evidence of tumor recurrence during the period of 12 months follow-up.

CONCLUSION

To our best knowledge, this is the first report of combined thymic epithelial tumor with MEC component. Although this tumor is rare, the diagnosis of a thymic MEC should be taken into consideration when a combined epithelial tumor is occasionally encountered in thymus.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9721397571157894.

Mucoepidermoid carcinoma of the thymus

Mucoepidermoid carcinoma of the thymus is a rare carcinoma and there is little agreement about the treatment of this tumor. According to the analysis of previously reported tumors, biologic behavior of the tumor correlated with the spread of the lesion and degree of differentiation. We report a case of this tumor in a 31-year-old man. Resection of the tumor included the left upper lobe of the lung, the phrenic nerve, pericardium and disseminations in the pleura. The clinicopathological feature of this case was high-stage disease and low-grade histology. Postoperative chemotherapy and radiotherapy were performed, and the patient is alive without recurrence 14 months after surgery.