Primary cardiac granular cell tumor in a dog

Area of Science:

• Veterinary Pathology
• Cardiovascular Oncology
• Comparative Oncology

Background:

• Granular cell tumors (GCTs) are uncommon neoplasms.
• Cardiac tumors in animals are rare, with GCTs in the heart being previously unreported.
• Understanding the origin and characteristics of rare tumors is crucial for diagnosis and treatment.

Observation:

• This study describes a granular cell tumor in the right atrium of a nine-year-old dog.
• Histological examination revealed areas of spindle-shaped cells and sheets of globoid cells with granular cytoplasm.
• Periodic acid-Schiff staining showed variable positivity in the cytoplasmic granules, with and without diastase digestion.

Findings:

• Ultrastructural analysis identified numerous heterogeneous lysosomes within the globoid neoplastic cells.
• This represents the first reported case of a granular cell tumor originating in the heart of an animal.
• The presence of nervous tissue-specific proteins supports a potential neural origin for these cardiac GCTs.

Implications:

• This case expands the known anatomical locations for granular cell tumors in veterinary medicine.
• Further research into the cell of origin and molecular characteristics of GCTs is warranted.
• Understanding these rare cardiac tumors can improve diagnosis and inform potential therapeutic strategies in affected animals.