Clinical presentation, treatment and outcome in 23 cats with laryngeal or tracheal lymphoma

Clinical characterisation and long-term survival of paediatric and juvenile lymphoma in cats: 33 cases (2008-2022)

OBJECTIVES

The aims of this study were to describe the clinical presentation, tumour characteristics, responses to chemotherapy protocols and toxicity in a cohort of cats with lymphoma up to 18 months of age. In addition, the probability of long-term (>2 years) survival was explored.

MATERIALS AND METHODS

The medical records of client-owned cats aged up to 18 months diagnosed with lymphoma between 2008 and 2022 at five UK-based veterinary referral hospitals were reviewed.

RESULTS

Thirty-three cats were included. The most common anatomical forms were mediastinal (42%), disseminated disease (30%) and renal (15%), with all cats having intermediate to large cell lymphoma. Three out of 29 cats tested were positive for FeLV but none for FIV. Twenty-six cats were treated with multi-agent chemotherapy protocols with complete and partial responses seen in 46% and 50% of cats, respectively. For this group, median progression-free survival was 133 days (95% confidence interval [Cl] 67 to 199) and median survival time was 268 days (95% Cl 106 to 430). Complete response to chemotherapy was associated with a longer progression-free survival. Seven cats were considered long-term survivors (>2 years). Chemotherapy was generally well tolerated with none of the long-term survivors suffering from chronic sequelae from cytotoxic treatment.

CLINICAL SIGNIFICANCE

Paediatric and juvenile cats with lymphoma showed a high response rate to multi-agent chemotherapy protocols with rare significant toxicities. The presence of long-term survivors may suggest a more favourable outcome in a subset of patients.

Clinical features, MRI findings and outcome of a primary extranodal B-cell lymphoma affecting the tympanic bulla treated with chemotherapy alone

Case summary

A 2-year-old neutered female feline leukaemia virus (FeLV)-negative domestic shorthair cat was referred with an acute onset of vestibular signs. A clinical examination identified evidence of otitis externa of the right ear and enlargement of the right mandibular lymph node. MRI revealed predominantly T2 and FLAIR hyperintense and contrast-enhancing lesions affecting the right external ear canal, tympanic bulla and nasopharyngeal regions with intracranial extension. Cytology and culture and sensitivity samples collected from the middle ear via myringotomy revealed a population of intermediate to large lymphocytes consistent with lymphoma and mixed Staphylococcus chromogenes and Pasteurella species infection. PCR for antigen receptor rearrangements on the ear cytology was consistent with a B-cell rearrangement. A primary extranodal B-cell lymphoma affecting the tympanic bulla and other sites with secondary septic otitis media and interna was diagnosed. After the improvement of clinical conditions after corticosteroid, antibiotic and chemotherapy treatment, the cat was alive 22 months after diagnosis without recurrence of clinical signs.

Relevance and novel information

This is the first report of a primary extranodal B-cell lymphoma affecting the tympanic bulla with suspected involvement of the nasopharynx and cranial vault treated with chemotherapy alone in the veterinary literature. Although very rare, B-cell lymphoma should be included in the differentials for diseases affecting the inner and/or middle ear and extending intracranially in cats. Chemotherapy represents a non-invasive treatment modality with a survival of up to 22 months appearing possible.