Laryngeal Lymphoma: Definition and Clinical Characteristics
Laryngeal lymphoma is a rare extranodal non-Hodgkin lymphoma that accounts for less than 1% of all primary laryngeal neoplasms, representing a distinct entity from the squamous cell carcinoma that comprises over 90% of laryngeal malignancies. 1, 2
Epidemiology and Rarity
- Primary laryngeal lymphoma is exceedingly uncommon, with fewer than 100 cases reported in the medical literature 3
- This malignancy represents a stark contrast to laryngeal squamous cell carcinoma, which accounts for approximately 95% of all primary laryngeal cancers 4
- The mean age at diagnosis is approximately 63 years, with a 2:1 female predominance 3
Anatomic Distribution and Tumor Characteristics
- The supraglottis is the most commonly affected laryngeal subsite, involved in 100% of reported cases 3, 5
- Tumors frequently extend beyond the supraglottis to involve the glottis (65-100% of cases) and hypopharynx (60-100% of cases) 3, 5
- The subglottis is less frequently involved (35-50% of cases) 3, 5
- Laryngeal lymphoma typically presents as a large submucosal tumor with an average size of 37 ± 19 mm 3
- Approximately one-third of cases involve cervical lymph nodes at presentation 6
Histologic Subtypes
- Diffuse large B-cell lymphoma (DLBCL) is the most common histologic subtype encountered in laryngeal lymphoma 1, 7
- NK/T-cell lymphoma represents another rare variant, with only 31 cases reported in the English, Japanese, and Chinese literature combined 6
- Mucosa-associated lymphoid tissue (MALT) lymphoma is a less common differential consideration that requires distinction through detailed immunocytochemical and cytogenetic characterization 7
Distinguishing Imaging Features from Squamous Cell Carcinoma
Laryngeal lymphoma demonstrates characteristic imaging features that can help distinguish it from the far more common squamous cell carcinoma:
- Uniformly enhancing supraglottic tumor without central necrosis (73% show uniform enhancement) 3
- Absence of cervical lymphadenopathy in 80% of cases, contrasting with squamous cell carcinoma 3
- Large submucosal component centered in the supraglottis 5
- Consistently FDG-avid on PET imaging (100% of cases) 3
- Absence of necrosis and calcification 3
- Laryngeal cartilage invasion occurs in only 20-25% of cases, less frequent than squamous cell carcinoma 3, 5
Clinical Presentation
- Symptoms are nonspecific and difficult to differentiate from other laryngeal diseases, including dysphagia, hoarseness, and throat discomfort 6, 7
- The nonspecific presentation often leads to diagnostic delays, with most patients requiring multiple biopsies over several months before diagnosis confirmation 6, 1
Diagnostic Challenges
A critical pitfall in diagnosing laryngeal lymphoma is the difficulty obtaining adequate tissue samples, necessitating repeated biopsies and sometimes requiring lymph node biopsy when laryngeal biopsies are non-diagnostic. 1
- Thorough phenotypic and cytogenetic characterization is essential to distinguish DLBCL from MALT lymphoma, as this distinction has direct therapeutic implications 7
- Immunocytochemical profiles with flow cytometry, chromosomal aberrations using banded karyotyping, and PET-CT imaging for disease extent are recommended for complete characterization 7