Cervicothoracic Mass Revealing a Non-Hodgkin's Lymphoma (NHL) and Its Unusual Localization: A Case Report

Aims: We aimed to report a rare case of a cervicothoracic mass revealing Non-Hodgkin's Lymphoma (NHL), highlighting its unusual localization. Non-Hodgkin's Lymphoma (NHL) is a rare condition, primarily affecting lymph nodes but can involve any organ. Extra-nodal NHL occurs in 25% of cases, with 60% located in the head and neck region. NHL in this area presents diverse clinical, morphological, and biological features, reflecting the complexity of histopathological classifications. Diagnosis relies on histology, which guides therapeutic management. This case report describes a cervicothoracic mass revealing laryngeal NHL. A 70-year-old man with a history of diabetes and hypertension, was admitted to the ENT department with a 10-month history of a painless left laterocervical swelling, dysphonia, and deteriorating general condition, without signs of tuberculosis, dyspnea, or initial dysphagia. ENT examination revealed a large, adherent, painless left laterocervical mass extending intrathoracically, associated with left upper limb lymphedema. Nasofibroscopy showed left laryngeal paralysis and deviation of the left hemi-laryngeal structures. Blood tests indicated bicytopenia. A CT scan identified a lesion in the left hemi-larynx with thyroid cartilage lysis and a cervical tumor extending into the cervico-thoracic area, displacing the trachea and esophagus. No lung nodules or mediastinal lymphadenopathy were observed. MRI confirmed a cervico-thoracic tumor with diffusion hypersignal, low ADC, and homogeneous enhancement, closely associated with the left thyroid lobe. Direct laryngoscopy and biopsy revealed diffuse large B-cell lymphoma (non-germinal type). Immunohistochemistry showed tumor cells positive for CD20, Bc16, and Mum1, negative for CD3, CD5, CD20, AE1/AE3, and Cyclin D1, with a high Ki67 proliferation index of 90%.