Calvarial hyperostosis syndrome in a Dalmatian dog

Abstract

Key clinical message: Calvarial hyperostosis syndrome is an uncommon and self-limiting disease affecting juvenile dogs. Only symptomatic treatment has been described, and diagnosis is based on clinical findings, imaging, and disease progression.

Abstract: This is the first reported case of calvarial hyperostosis syndrome in a Dalmatian dog. It is an uncommon osteoproliferative disease with diagnosis frequently based on clinical signs, imaging findings, and disease progression, with only symptomatic treatment described. Case describes a 5-month-old Dalmatian dog presented with a facial mass and difficulty eating. After imaging, mass was observed to be osteoproliferative, nonaggressive, and without affection of the temporomandibular joints and mandibles. Histology revealed an osseous-cartilaginous and proliferative lesion, together with scant amount of neutrophiles. Clinical improvement was observed after symptomatic treatment, and moderate lesion regression was observed in a CT reevaluation 6 months later.

Keywords: Dalmatian; calvarial; hyperostosis; osteoproliferative; self‐limiting.

FIGURE 1

DV (A) and oblique (B) radiographs of the skull, showing the rounded mass (white arrows) of mineral opacity, located at the region of the right tympanic bulla.

FIGURE 2

CT study of the skull in bone algorithm from rostral to caudal (A–C), showing the mass‐like lesion at the right temporomandibular region, with increased bilateral thickness and hyperattenuation of the temporal, parietal, and occipital bones. Both temporomandibular joints are within normal limits.

FIGURE 3

Histopathologic (HE) image showed trabeculae composed by two components; woven bone, and cartilage with irregular resting lines. Trabeculae show small medullary spaces lined by normal osteoblasts and few osteoclasts.

FIGURE 4

Skull CT 6 months after diagnosis, at the same level of the images of Figure 1. Absence of the previously described thickening and hyperattenuation of the temporal, parietal, and occipital bones. The mass‐like lesion at the region of the temporomandibular joint has a more compacted appearance.

FIGURE 5

Comparative 3D reconstructions in VD position of the initial study (A) and 6 months after diagnosis (B). A moderate decrease of the mass volume is observed.