Calcinosis cutis in dogs: histopathological and clinical analysis of 46 cases

Abstract

Background -Calcinosis cutis is well recognized in dogs with endogenous hyperglucocorticism and iatrogenic hyperglucocorticism, but the pathogenesis is still unclear.Objectives -The objectives of the study were to identify possible correlations between histopathological patterns of dermal mineralization in skin biopsies and underlying causes for calcinosis cutis in dogs, as well as to determine breed predilection and age of onset for dogs within a hospital population. In addition, mineral analysis was performed on four biopsy samples.Animals -Forty-six dogs with histopathologically confirmed calcinosis cutis were evaluated.Methods -Medical records and histological sections of dogs with calcinosis cutis diagnosed by histopathology over a 21 year period were reviewed. Infrared spectrometry was used to identify the mineral in the paraffin blocks. Exact chi-squared test was used to identify breed predispositions, while a Mann-Whitney U-test was used to identify age correlations.Results -Labrador retrievers, Rottweilers, boxers and Staffordshire terriers were the breeds most commonly affected in this study. Most dogs had either an exogenous or an endogenous source of corticosteroids, with the exception of five dogs with renal insufficiency. In the majority of cases, mineralization was found throughout the entire dermis. The average age of onset of calcinosis cutis for dogs with endogenous hyperglucocorticism was older than that of dogs with iatrogenic hyperglucocorticism. Using infrared spectrometry, apatite crystals were found to be the source of mineral.Conclusions and clinical importance -There was no observable difference in the histopathological pattern of calcinosis cutis from dogs with endogenous hyperglucocorticism versus iatrogenic hyperglucocorticism. While glucocorticoid therapy appears to predispose dogs to developing calcinosis cutis, it remains unclear whether there is a specific dose or combination of factors that initiates the mineral deposition. Furthermore, the mineral deposition in dogs with calcinosis cutis was found to be apatite.

Primary isolated osteoma cutis causing eyelid deformation and strabismus in a dog

“…Heterotopic ossification in skin has historically been termed osteoma cutis and is a rare condition in people . It is further divided into primary and secondary osteoma cutis based on pathogenesis .…”

“…Despite the isolated nature of the osteoma cutis in the cat and turtle, the ossification caused significant morbidity prompting veterinary attention similar to the juvenile samoyed in our case. In the dog, cases of secondary osteoma cutis are more common and have been reported mostly as a consequence of naturally occurring or iatrogenic hyperadrenocorticism . In people, primary osteoma cutis has only infrequently involved the eyelids and it has not been previously documented in this location in veterinary medicine .…”

“…Heterotopic ossification is the formation of bone outside the skeletal system. It can occur in a variety of soft tissues including skeletal muscle, ligaments, blood vessel walls, and skin When heterotopic ossification occurs in skin, it is referred to as osteoma cutis and it is rarely diagnosed in both human and veterinary medicine . Osteoma cutis is classified as primary or secondary based on the underlying pathogenesis of the bone formation.…”

“…Osteoma cutis is classified as primary or secondary based on the underlying pathogenesis of the bone formation. In veterinary medicine, the vast majority of cases in dogs described in the literature are classified as secondary . Ossifications in osteoma cutis are considered benign, with neither infiltrative nor metastatic potential and lesions are generally painless, sometimes easier to feel than see …”

Mast cell quantification in the skin of dogs with hormonal dermatosis

“…In the group with hypothyroidism and signs of seborrhea mast cell infiltrate in the dermis had been observed (Rojko et al, 1978). Animals with hyperadrenocorticism showed histopathological signs of inflammation, but only when associated with dermal collagen mineralization (Rojko et al, 1978;Doerr et al, 2013).…”