Non-sebaceous lymphadenoma-like mucoepidermoid carcinoma: A case report

Non-sebaceous lymphadenoma is a rare benign salivary gland tumor comprised of non-sebaceous epithelial cells and lymphoid tissue. Although its clinicopathological features have been described, its histogenesis and genetic background have not yet been elucidated. MAML2 rearrangement and the resultant CRTC1/3-MAML2 fusion gene are well-known specific genetic changes in mucoepidermoid carcinoma. Here, we present a case of lymphoepithelial tumor characterized by histomorphology of the non-sebaceous lymphadenoma and CRTC1-MAML2 fusion gene. The patient was an 83-year-old woman with an 8-year history of a solid, well-circumscribed tumor in the parotid gland. Histologically, the tumor was surrounded by thin fibrous connective tissue and was composed of tubular-cystic and solid nests of epithelial cells equally distributed in the lymphoid tissue. The histological features were suggestive of non-sebaceous lymphadenoma. Although the histomorphology was not consistent with mucoepidermoid carcinoma, a diagnosis of non-sebaceous lymphadenoma-like mucoepidermoid carcinoma was made based on the presence of the CRTC1-MAML2 fusion gene. The histological features alone could not establish the diagnosis, and ancillary molecular analysis was required.

Non-sebaceous Lymphadenoma of the Parotid Gland Mimicking a Pleomorphic Adenoma

Non-sebaceous lymphadenoma of the salivary glands is a rare benign lesion, first described in 1991. We present the case of a 54-year-old woman, with a right parotid mass. She underwent right superficial parotidectomy, and histopathology reported a non-sebaceous lymphadenoma due to an encapsulated lesion and multiple non-atypical epithelial inclusions without sebaceous differentiation. The etiology of non-sebaceous lymphadenoma is not yet understood, but it can arise predominantly from the parotid gland. Surgical excision is the treatment of choice.

Lymphadenoma of the salivary gland: Report of 10 cases

Lymphadenoma of the salivary gland is rare, and the typical characteristics of lymphadenoma remain poorly understood. The aim of this study was to analyze the experience of a single institution in the clinical diagnosis, treatment and prognosis of this type of tumor of the salivary gland. All cases of lymphadenoma diagnosed at the institution between 1996 and 2012 were analyzed. The clinical information (including age, gender and tumor location, process of tumor development, imaging data, surgical treatment and follow-up information) and pathological features were evaluated. All tumors occurred in the parotid glands; three cases were sebaceous lymphadenoma (two male and one female) and seven were non-sebaceous lymphadenoma (three male and four female). The average ages of the patients were 68.3 and 42.4 years for the sebaceous and non-sebaceous groups, respectively. The majority of cases (90%) were diagnosed as pleomorphic adenoma or adenolymphoma prior to surgery, but were confirmed as lymphadenoma by pathological analysis following surgery. During the follow-up period, which ranged between 3 and 36 months with a mean of 30 months, no recurrence of the lesion was identified and the quality of life was good for each patient. In conclusion, the diagnosis of salivary gland lymphadenoma should be based on the clinical and, in particular, the pathological manifestations of the disease. Immunohistochemistry is considered as a practical and helpful adjuvant method of the diagnosis for this type of tumor. Complete surgical resection is the first choice of treatment. Further exploration of the histological origin of lymphadenoma of the salivary gland is necessary due to the insufficient number of reported cases.