Extranodal Marginal Zone Lymphoma of the Floor of the Mouth: A Rare Entity With Management Challenges
- 1Department of Radiation Oncology, Hassan II Oncology Center, Mohammed VI University Hospital, Faculty of Medicine and Pharmacy, Oujda, MAR
- 2Department of Radiation Oncology, Hassan II Oncology Center, Mohammed VI University Hospital, Oujda, MAR
Abstract
Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) involving the oral cavity is rare, and localization to the floor of the mouth is particularly uncommon. Its indolent course and nonspecific clinical presentation may lead to diagnostic and therapeutic challenges. Diagnosis relies on histopathological examination combined with immunohistochemical analysis to establish the B-cell phenotype and exclude other small B-cell lymphomas. We report the case of a 48-year-old man with stage IIE MALT lymphoma of the floor of the mouth associated with ipsilateral submandibular lymph node involvement. Given the large tumor volume, systemic therapy was initially favored. The patient received four cycles of rituximab monotherapy with an insufficient response. A repeat biopsy excluded histological transformation, and rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone chemoimmunotherapy was subsequently administered, with persistent local disease. External radiotherapy was then delivered to the oral cavity and cervical lymph node regions (24 Gy), with a boost to the floor-of-mouth lesion to a total dose of 30 Gy. Follow-up positron emission tomography/computed tomography demonstrated a complete metabolic response, and the patient remained clinically free of recurrence 18 months after radiotherapy. This case highlights the diagnostic and therapeutic challenges of MALT lymphoma at an exceptional oral site and illustrates the importance of radiotherapy in achieving local disease control after an insufficient response to systemic therapy.
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BibTeX
@article{mouhib2026extranodal,
title = {{Extranodal Marginal Zone Lymphoma of the Floor of the Mouth: A Rare Entity With Management Challenges}},
author = {Nourelhouda Mouhib and Berhili Soufiane and Souad Margoum and Ahmed Bensghier and Mohamed Moukhlissi and Loubna Mezouar},
journal = {Cureus},
year = {2026},
month = oct,
doi = {10.7759/cureus.117490},
url = {https://doi.org/10.7759/cureus.117490},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Extranodal Marginal Zone Lymphoma of the Floor of the Mouth: A Rare Entity With Management Challenges
AU - Nourelhouda Mouhib
AU - Berhili Soufiane
AU - Souad Margoum
AU - Ahmed Bensghier
AU - Mohamed Moukhlissi
AU - Loubna Mezouar
PY - 2026
DA - 2026/10/05
JO - Cureus
DO - 10.7759/cureus.117490
UR - https://doi.org/10.7759/cureus.117490
AB - Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) involving the oral cavity is rare, and localization to the floor of the mouth is particularly uncommon. Its indolent course and nonspecific clinical presentation may lead to diagnostic and therapeutic challenges. Diagnosis relies on histopathological examination combined with immunohistochemical analysis to establish the B-cell phenotype and exclude other small B-cell lymphomas. We report the case of a 48-year-old man with stage IIE MALT lymphoma of the floor of the mouth associated with ipsilateral submandibular lymph node involvement. Given the large tumor volume, systemic therapy was initially favored. The patient received four cycles of rituximab monotherapy with an insufficient response. A repeat biopsy excluded histological transformation, and rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone chemoimmunotherapy was subsequently administered, with persistent local disease. External radiotherapy was then delivered to the oral cavity and cervical lymph node regions (24 Gy), with a boost to the floor-of-mouth lesion to a total dose of 30 Gy. Follow-up positron emission tomography/computed tomography demonstrated a complete metabolic response, and the patient remained clinically free of recurrence 18 months after radiotherapy. This case highlights the diagnostic and therapeutic challenges of MALT lymphoma at an exceptional oral site and illustrates the importance of radiotherapy in achieving local disease control after an insufficient response to systemic therapy.
SN - 2168-8184
ER -