This is a thirteen and a half year old Patterdale terrier with an acute appearance of a lump on top of it's head. There was no improvement after being given a course of antibiotics. Lateral and dorso ventral skull radiographs were taken. Scroll down for radiographs:
Fig. 1: Lateral view of the skull
Fig. 2. Dorso ventral view of the skull
At the level of the frontal sinuses extending mildly caudally over the frontal bone and rostrally to the level of the caudal maxilla there is a moderately sized relatively homogenously soft tissue opaque mass, measuring approximately 7.2cm in length and 2cm in height (the width can not be determined because the mass is not visualized on the DV). There appears to be associated multifocal osseous lysis of the frontal bone at the level of the frontal sinuses. There is no evidence of bone matrix extending into the mass. The frontal sinuses have an increased opacity. There is no radiographic evidence of the mass extending into the nasal cavity. There is a mild apical lucency surrounding the roots of the right mandibular fourth premolar and one of the maxillary molars. The remainder of the study is normal.
Fig 3: Lateral view of the skull; rostral is to the left. Green arrows indicate a large soft tissue mass at the level of the frontal sinuses. There appears to be associated multifocal osseous lysis of the frontal bone (green arrow heads). Pink arrows indicate mild endodontal disease.
1. Osteolytic mass at the level of the frontal sinus (possibly invading the frontal sinuses). Differentials include an abscess with secondary osteomyelitis, however neoplasia can not be ruled out.
2. Multifocal mild endodontal disease.
Based on imaging alone it is difficult to differentiate between the two differentials. Therefore, tissue sampling could be performed. For further evaluation of the mass a pre- and post-contrast CT of the head could be performed. With this the extent of the mass, additional osteolysis and the regional lymph nodes can be evaluated.
This dog was referred to a specialist centre and had a CT of the head and thorax. A fine needle aspirate of the mass identified an aggressive soft neoplasia. The dog was managed at home on antibiotics for the secondary infection, non steroidal anti inflammatory drugs and tramadol for analgesia, and was unfortunately euthanised within a few weeks.