Primary mucosa-associated lymphoid tissue lymphoma of the sublingual gland: a case report

Lymphomas Affecting the Sublingual Glands: A Clinicopathological Study

BACKGROUND

Lymphomas affecting the sublingual glands are extremely rare and very few case reports are currently available. Therefore, the aim of the current study is to describe the clinicopathological features of a series of lymphomas involving the sublingual glands.

METHODS

Cases diagnosed in four pathology services were assessed and the formalin-fixed paraffin-embedded tissue blocks were retrieved for diagnosis confirmation. Clinical data were obtained from patients' medical files.

RESULTS

We obtained seven cases of lymphomas in the sublingual glands, representing two follicular lymphomas, two diffuse large B cell lymphomas not otherwise specified (DLBCL NOS), two extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphomas) and one mantle cell lymphoma (MCL). In all cases the tumor cells infiltrated the glandular parenchyma, although in two of them the neoplastic cells were located more superficially and permeated the glandular acini and ducts. Clinically, the tumors presented as asymptomatic nodules and two patients (affected by DLBCL NOS and MCL) died, while the other five patients remained alive at last follow-up.

CONCLUSION

Lymphomas affecting the sublingual glands are usually of the mature B cell lineage, often represent low-grade subtypes and may clinically resemble other more common lesions in the floor of the mouth like salivary gland tumors.

Lymphoma of the Sublingual Gland: Clinical, Morphological, Histopathological, and Genetic Characterization

Background: Lymphoma of the sublingual gland is rare, representing 1% of all salivary gland lymphomas. In this case report, we present three new cases and compare them to previously published cases, with the aim of characterizing the clinical, morphological, histopathological, and genetic features of this type of malignancy.

Materials and Methods: We provide a clinical description of three cases along with a characterization of the microscopic features, including morphology, and immunohistochemistry. In addition, we analysed possible cytogenetic rearrangements with the use of fluorescence in situ hybridization (FISH).

Results: Case 1: A 61-year-old male presenting with a painless swelling of the floor of the mouth diagnosed as extranodal marginal zone lymphoma (EMZL) of the left sublingual gland. The patient is alive with no evidence of disease after his fourth treatment regimen following several relapses. Case 2: A 68-year-old female with a prior history of mantle cell lymphoma (MCL) presenting with a tender swelling of the left sublingual gland as well as the right submandibular gland. The lesions were diagnosed as relapsing MCL. The patient died of unrelated causes after 18 months of treatment. Case 3: A 75-year-old female presenting with a swelling of the floor of the mouth diagnosed as follicular lymphoma (FL) of the left sublingual gland. The patient received chemotherapy along with radiotherapy and was still alive 10 years after the diagnosis.

Conclusion: The three cases of sublingual gland lymphomas presented in this case report resemble lymphomas of other major salivary glands. The clinician should be aware of this type of malignancy and that the clinical presentation may not differ from benign lesions or other more common malignancies in this location.