Plasma cell tumour affecting the skull in a dog

Abstract

An 8-year-old, 27-kg, spayed, female, mixed-breed dog was presented for recent onset of epileptic seizures. In addition to mild neurological deficits, the dog had a palpable mass on the dorsal midline aspect of the skull. Magnetic resonance imaging of the head and postmortem computed tomography of the head, vertebral column, thorax and abdomen revealed a mass affecting the skull and multifocal lesions in the brain and lungs. The dog was euthanased, and postmortem biopsies from the skull mass were collected for cytological and histological examination. Cytology findings were suggestive of a malignant round-cell neoplasm of suspected plasmacytoid origin, and histopathology was consistent with a plasmacytoma. The imaging findings of the skull mass in this patient add to those described earlier and may help in recognising this type of tumour in future cases. Whether the other mass lesions were of plasma cell origin or of a different nature remains unclear.