+ Signalment

  • Mean age 7 years for benign tumors and 11 years for malignant tumors
  • No sex predilection
  • Benign aural tumors: inflammatory polyp, papilloma, basal cell tumor, and ceruminous gland adenoma
  • Ceruminous gland cysts are tumor-like lesions in cats which appear as sessile, blue-black masses
  • Malignant aural tumors: ceruminous gland ADC, SCC, and other cutaneous tumors
  • Ceruminous gland ADC is more common than ceruminous gland adenoma
  • Malignant tumors tend to be locally invasive with a low metastatic potential (15% to regional lymph node and lungs)

+ Clinical Signs

  • Mass
  • Aural discharge, odour, pruritis, and local pain
  • Neurologic signs in 10% of dogs with malignant aural tumors
  • Duration of clinical signs prior to presentation is usually prolonged (months to years)
  • Benign tumors are usually raised and pedunculated with rare ulceration
  • Malignant tumors usually have a broad base with ulceration and hemorrhage
  • 25% of malignant tumors have bulla involvement

+ Diagnosis

  • Otoscope
  • Survey radiographs
  • CT

+ Treatment

  • Surgical resection
  • TECA-LBO for malignant tumors
  • Lateral or vertical ear wall resection for benign tumors
  • Caudal auricular approach described for cholesteotoma
  • Radiation therapy as either primary or adjunctive treatment

+ Prognosis

  • MST 11.7-50.3 months, but majority of cats die for reasons unrelated to aural tumor
  • Malignant aural tumors are more aggressive in cats than dogs
  • Poor prognostic factors include neurologic signs, histopathology of SCC or undifferentiated carcinoma, lymphatic or vascular invasion, and conservative surgery
  • MST significantly worse for cats with neurologic signs (1.5 months v 15.5 months)
  • MST significantly better for cats with ceruminous gland ADC (49 months v 3.8 months for SCC and 5.7 months for undifferentiated carcinoma)
  • MST is significantly worse for tumors with lymphatic or vascular invasion (4.0 months v 21.7 months)
  • Local tumor recurrence rate (25% v 66%), median DFI (42 months v 10 months), and 12-month survival rate (75% v 33%)
  • Mitotic index of < 3 surviving significantly longer than cats with a mitotic index ≥ 3
  • Radiation therapy (48 Gy total dose): median DFI 40 months and 12-month survival rate 56%