Features of the pharyngeal cancer diagnostics

Early diagnosis is crucial for an effective cancer management. Cancers of the head and neck, and the ENT organs in particular, are among the top ten most common human malignancies. The human upper respiratory tract is most affected by squamous cell carcinomas, lymphomas, and adenoid cystic carcinomas. Nasopharyngeal neoplasms are characterized by mild and non-specific manifestations, especially at the initial stages of development. Mild symptoms and the localization peculiarities result in the delayed diagnosis of these tumors. Lymphomas localized in the pharynx can cause several pathological conditions: postnasal congestion syndrome, auditory tube dysfunction, recurrent inflammatory processes in the middle ear, snoring. MALT-lymphoma is a low-grade B-cell non-Hodgkin lymphoma. It is necessary to remember MALT-lymphoma can transform into diffuse large B-cell lymphoma, which belongs to aggressive lymphomas.

The article describes a clinical case of MALT-lymphoma localized in the pharynx and parapharyngeal space in a 63-year-old patient. The patient was observed on an outpatient basis for more than 3 years for recurrent otitis media and complaints of difficulty in nasal breathing, snoring and mucus trickling down the back wall of the pharynx. Due to the ineffectiveness of conservative treatment (topical corticosteroid drugs, intranasal decongestants, ear drops), the patient was referred to the L. I. Sverzhevsky RCIO. Endoscopic examination of the nasopharynx revealed a tumor of the nasopharyngeal arch passing to the area of tori tubarii. Audiological examination confirmed the concomitant diagnosis — exudative otitis media. According to contrast-enhanced computer tomography of the pharynx, the formation spread into the parapharyngeal space, without signs of bone invasion. After X-ray examination, a biopsy was taken from three tumor foci: the middle of the posterior wall of the nasopharynx and the paratubar region. Considering the morphological picture, an additional immunohistochemical study of the material was performed on Ventana Benchmark XT (universal staining system) using anti-CD20 (clone L26 Ventana), ultra View Universal DAB Detection Kit (Ventana). The morphological pattern corresponded to a small B-cell non-Hodgkin lymphoma; more likely, to the lymphoma of the marginal zone of the mucosa-associated lymphoid tissue (MALT-lymphoma). For further treatment, the patient was referred to an oncological institution.
The clinical case demonstrates that only the complex implementation of modern endoscopic, radiological, and morphological methods helps in verifying the diagnosis in order to choose the correct treatment and reach a favorable outcome for such a serious disease. The article presents a diagnostic algorithm for suspected malignant neoplasm of the pharynx. Lymphomas have the following radiological features: they spread only within the prestyloid space; they do not affect bone structures; they have a smooth, free surface; the contrast agent is evenly accumulated; as a rule, there are no calcifications, hemorrhages, necrotic and cystic changes in the structure of the lymphoma; pharyngeal lymphoma rather obstructs the lumen of the respiratory tract than invades the underlying tissues. A biopsy of a neoplasm at the stage of examination by an otorhinolaryngologist can accelerate the referral of a cancer patient to a specialist. Multifocal tumor biopsy increases the probability of a correct diagnosis based on the results of a pathomorphological examination.

Key words: MALT-lymphoma, exudative otitis media, auditory tube dysfunction, pharyngeal MSCT, contrast, immunohistochemistry, neoplasm

Conflicts of interest. The authors have no conflicts of interest to declare.
Funding. There was no funding for this study.