An 8-year-old male (neutered) Labrador with a history of erythematous skin lesions and exercise intolerance for a prolonged period was suddenly found dead. Necropsy findings revealed an infiltrative, focally extensive mass which occupied 25% of the cardiac interventricular septum. Severe endocardiosis was also found on the bicuspid and tricuspid valves. The submandibular lymph nodes and kidneys were bilaterally enlarged, and the pre-hepatic lymph node and spleen were also enlarged. Multiple dermal pustules were present around the mouth and on the ear, and small ulcers were present on the tongue. Histopathological examination detected the presence of neoplastic lymphocytes with a plasmacytoid morphology in these tissues as well as in the tongue and skin lesions. Immunohistochemical (CD3+/CD18+) evaluation was consistent with a T-cell lymphoma, which could be classified as a peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS).
Ocular histiocytic sarcomas (as a presenting part of disseminated histiocytic sarcoma) are not commonly diagnosed. A 10-year-old female intact Rottweiler presented to the School of Veterinary Medicine, Trinidad with buphthalmia and pain in the left eye. The cornea of the left eye appeared diffusely opaque with a conjunctival mucopurulent ocular discharge. A thorough ophthalmic assessment identified an intraocular proliferative tumor to which a unilateral enucleation was performed, however the animal died soon after. Post mortem examination and light microscopy revealed that the intraocular lesion with visceral macro-metastases was in fact a histiocytic sarcoma. Further to this, immune-phenotyping was performed to confirm the diagnosis of disseminated histiocytic sarcoma. This is the first time such a tumor has been diagnosed in Trinidad and Tobago.