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 25% of cats with malignant aural tumors, especially SCC, due to local invasion

•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, and CT

Treatment

•surgical resection

•TECA-LBO for malignant tumors

•lateral or vertical ear wall resection for benign tumors

•facial nerve paralysis is 2-times as likely following TECA-LBO in a cat with neoplasia

•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%