Subcutaneous fibrosarcoma in an aged guinea pig

Area of Science:

• Veterinary Pathology
• Comparative Oncology
• Small Mammal Medicine

Background:

• Fibrosarcomas are malignant tumors that can occur in various species.
• Guinea pigs, while not commonly studied for fibrosarcomas, can develop spontaneous neoplasms.
• Understanding tumor behavior and concurrent conditions in exotic pets is crucial for diagnosis and treatment.

Observation:

• A 9-year-old, female guinea pig was presented with a palpable mass on its ventral thorax.
• The mass was identified as a subcutaneous fibrosarcoma.
• Diagnostic imaging and histopathology confirmed the invasive nature of the tumor within the subcutis.

Findings:

• The fibrosarcoma was invasive but did not extend into surrounding structures or organ systems.
• Concurrent findings included cystic ovaries, renal cortical cysts, and nodular hyperplasia of the liver.
• Myocardial fibrosis with secondary pulmonary hypertension was also noted.

Implications:

• This case highlights the potential for localized subcutaneous fibrosarcomas in guinea pigs.
• The presence of multiple concurrent pathologies, including reproductive and hepatic changes, underscores the importance of thorough systemic evaluation in aged guinea pigs.
• Further research into fibrosarcoma development and progression in this species may inform clinical management and improve outcomes.