A Study on Neoplastic and Non-neoplastic Masses in Companion Animal Patients in Malang Raya: Histological Classification and Case Proportion

Background: Understanding the case proportion of neoplastic and non-neoplastic disease in companion animals could reveal the trends; novel subtypes architectures, differential diagnoses and disease prognoses based on histopathological features for clinical purposes and future epidemiological study. This study aimed to explore trends, patterns, histopathological features and potential paraneoplastic syndromes associated with tumors in companion animals. Methods: Archived neoplastic tissue samples were collected over five years from an animal hospital, clinics, and veterinary practitioners in Malang Raya, Indonesia and processed through routine histopathologic examination. Results: A minimum of 30 feline and 40 canine patients with confirmed neoplastic lesions were identified, with glandular tumors being the most frequently reported in both species. Twenty-four non-neoplastic superficial masses were also reported including subcutaneous abscess, granulomatous dermatitis, pseudomycetoma/deep fungal mycosis, and panniculitis. Different regions worldwide may show varying prevalence rates and distinct patterns in the most frequently encountered abnormal superficial masses. Conclusions: Understanding these trends and considering the potential differential diagnoses can assist diagnosticians in systematically ruling out less likely conditions. The significant/notable proportion of neoplastic cases in companion animals underscores the importance of further investigations into possible environmental carcinogens, which may also pose risks to human health.