A rare case of mucoepidermoid carcinoma ex pleomorphic adenoma of the lacrimal gland

Medium-sized buccal mucosa defect reconstruction with buccal advancement flap in mucoepidermoid carcinoma ex pleomorphic adenoma: a case report

Introduction and importance

Mucoepidermoid carcinoma (MEC) ex pleomorphic adenoma is a rare type of salivary gland cancer. Surgical resection remains the standard therapy for this malignancy. After tumor removal, larger defects may require a local, regional, or free flap, while smaller ones can be closed primarily. Managing medium-sized defects can be challenging, especially on the buccal mucosa.

Presentation of case

A 47-year-old man had a buccal mucosa mass for 10 years, which gradually grew over a year and irritated his chewing. A 2.2×2 cm buccal mass was observed with telangiectatic and erythematous alterations in the surrounding mucosa. The preoperative tissue biopsy suggested salivary gland malignancy. The patient underwent surgical excision and a single-stage buccal advancement flap reconstruction, successfully closing the 4 cm defect. The final diagnosis was MEC ex pleomorphic adenoma. He reported mild discomfort during the first few months while opening his mouth. The patient had fully recovered after 6 months.

Clinical discussion

This is the first case of MEC arising in a pleomorphic adenoma of the buccal mucosa. For low-grade and small-sized tumors, a single modality is appropriate for treatment. Local flaps such as buccal fat pad or musculomucosal flap can repair medium-sized defects. However, the buccal advancement flap provides effective functional and esthetic benefits, optimal healing conditions, and reduces complications risk.

Conclusion

The buccal advancement flap is a valuable option for reconstructing medium-sized buccal defects up to 4 cm. The single-stage surgical procedure has been proven to yield minimal complications and provide a favorable outcome.

Clinicopathological practice in the differential diagnosis of mucoepidermoid carcinoma from neoplasms with mucinous component

Background

The differential diagnosis of mucoepidermoid carcinoma (MEC) from neoplasm undergoing mucinous features brings more pitfalls to pathologists. Combining specific MAML2 gene rearrangement and histological characteristics may be the solution.

Methods

Twenty-five tumors with mucinous components were selected for differential diagnosis of MEC. All the cases were detected for MAML2 gene rearrangement. The cases diagnosed as MEC were classified into four variants: classic, oncocytic, Warthin-like, and nonclassified, and they were graded using the Brandwein system. The histological characteristics of non-MECs were summarized for differential diagnosis. Univariate survival analysis was performed on MECs.

Results

There were 16 MECs; 62.5% were MAML2 rearranged. For the low-, intermediate-, and high-grade MECs, the rate of rearrangement was 83.3%, 100%, and 28.6%, respectively. Both the oncocytic and Warthin-like MECs were MAML2 rearranged. For the classic and nonclassified MECs without MAML2 rearrangement, non-keratinized squamoid cells and distinctive mucinous cells were essential diagnostic criteria. On survival analysis, all the disease progression occurred in high-grade MECs (p = 0.038). Nine cases were diagnosed as non-MECs: pleomorphic adenoma with mucinous metaplasia showed no ex-capsular involvement; metaplastic Warthin tumor appeared with overt keratinization and residual oncocytic bilayered epithelium; mix squamous cell and glandular papilloma showed an endobronchial papillary growing pattern; adenosquamous carcinoma was accompanied by squamous carcinoma in situ of the overlying mucosa. All the non-MECs were negative for MAML2 rearrangement.

Conclusion

The application of combining MAML2 rearrangement and histological characteristics is helpful in the differential diagnosis between MEC and other tumors with mucinous components.

Lacrimal gland mucoepidermoid carcinoma with contralateral eye and systemic metastasis: A rare case report and review of the literature

Lacrimal gland mucoepidermoid carcinoma is very rare. It has a high risk of recurrence and metastasis, however, it rarely metastasizes to the contralateral eye in clinical practice. Here, we present a case of a 52-year-old man with lacrimal gland mucoepidermoid carcinoma who developed multiple recurrences and metastases of another eye and other sites throughout the body after receiving surgical intervention and regular radiotherapy, which will be of ophthalmic interest and unique. Clinical features, imaging findings, histopathology, treatments, and outcomes of this very rare case are provided. A literature review of previously published cases of this disease is performed, with an emphasis on the latest diagnosis and treatment. The prognosis of tumor recurrence and metastasis is poorer, surgery with a negative margin in conjunction with adjuvant therapies is crucial for preventing local recurrence and distant metastasis and enhancing the survival rate.

Mucoepidermoid Carcinoma Ex Pleomorphic Adenoma of Lacrimal Gland: Case Report and Review of Literature

Carcinoma ex pleomorphic adenoma (Ca ex PA) is defined as an infiltrative carcinoma arising from a primary or recurrent benign pleomorphic adenoma. Ca ex PA with the histologic subtype mucoepidermoid carcinoma is extremely uncommon. Only 2 previous reports in the lacrimal gland have been documented. We reported a 55-year-old lady with a firm, solid, nontender mass in the supralateral quadrant of the right orbit at the area of the lacrimal gland. After wide excision of mass, pathology revealed high-grade mucoepidermoid carcinoma Ex pleomorphic adenoma. To reduce tumor recurrence 60 Gray radiation was delivered to the orbital cavity. She is still tumor-free 1 year after completion of treatment.