MN, Canine, Dachshund, 9 years old
5 punch biopsies taken of multicentric lesions left lower lip, left pinna, left tongue margin, hard palate and nail bed. Lesions are all ulcerated and eroded. Owner stopped prednisone 2 weeks ago, prior to biopsies being taken today. Lesions started on ear margins, expanded to nose, lips, tongue, hard palate and nailbeds. The lesions on the tongue are ulcerated but raised.Click here for the IDEXX Pathology Report on this case.
A: Left lower lip: Shallow ulcer is associated with prominent pigment incontinence and mild subacute to chronic inflammation. Small numbers of a acantholytic squamous are seen. There is prominent discohesion of epithelial cells at the basal cell layer.
B: Left side of tongue: Large ulcer is associated with a band of residual mildly pleomorphic plump oval to cuboidal basal epithelial cells at the base of the ulcer. Neutrophils and macrophages are associated with the residual basal epithelial cells. Submucosa contains thin bands of inflamed reactive fibrovascular stroma.
C: Nailbed: Large ulcer is present. Large irregular suprabasilar epidermal cleft with separation of the epidermis is associated with rows of residual cuboidal basal cells subjacent to the cleft. Clefting along the hair follicle infundibular is associated with inflammatory cell debris.
D: Hard palate: Suprabasilar clefting and ulceration are seen. Large groups of plump round disassociated squamous epithelial cells are seen above rows of mildly pleomorphic dysplastic plump cuboidal basal epithelial cells.
E: Left pinna: Large broad based suprabasilar bullae is present. Retained cords of basal epithelial cells are seen at the base of the bullae. Chronic lymphoplasmacytic granulomatous mastocytic inflammation with fibrosis is seen within the dermis. Moderate pigment incontinence is also seen.
Multicentric suprabasilar clefting with retained basal cell layer, ulceration and subacute to chronic inflammation
Of the variety of immune mediated and autoimmune skin diseases, pemphigus vulgaris is very rare. Desmoglein 3, a keratinocyte cadherin expressed mainly in the oral mucosa, is the target of the immune response. Desmoglein 1 is occasionally targeted as well and these cases will have lesions in the hired skin also.
Clinically there is erythema, vesicle formation, rupture of vesicles and erosions with secondary bacterial overgrowth and ulceration. Coalescing ulcers may be seen on the tongue, palate, and gingiva. Lips, concave surfaces of the pinna, nasal planum, lip margins, genitalia, anus, periorbital regions and claws may also be involved. Corneal and esophageal ulceration have also been reported. German Shepherd dogs and Collies and males may be over represented. Most dogs that develop PV are adult to aged though the disease has been seen in dogs <1 year of age.
Reference: Skin Diseases of the Dog and Cat, 2nd ed. Pp 32-35, 2005
Carroll J. Jones, DVM
Diplomate, American College of Veterinary Pathologists
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1 888 433 9987, option 0, x77927