Small Animal Dermatology, 3rd edition

CHAPTER 41 PRE- AND PARANEOPLASTIC SYNDROMES 621

Cutaneous mucinosis (secondary): causes of diffuse dermal edema, vesicular or

bullous dermatitis

Nodular dermatofibrosis: dermal neoplasia, infectious granuloma, sterile granu-

loma, pyogranulomatous dermatitis, fibroma, hematoma, nodular scar

Paraneoplastic pemphigus: pemphigus vulgaris, bullous pemphigoid, erythema

multiforme

Superficial necrolytic dermatitis: pemphigus foliaceus, zinc-responsive dermato-

sis, systemic lupus erythematosus, erythema multiforme, drug eruption, generic

dog food dermatosis, irritant contact dermatitis, demodicosis, dermatophytosis,

vasculitis, epitheliotropic lymphoma, toxic epidermal necrolysis.

 Feline preneoplastic dermatoses:
Actinic keratoses: squamous cell carcinoma, topical drug eruption, severe con-

tact dermatitis

Cutaneous lymphocytosis: epitheliotropic lymphoma, hypersensitivity reaction,

drug eruption, bacterial folliculitis, dermatophytosis.

 Feline paraneoplastic dermatoses:
Pancreatic/hepatic paraneoplastic alopecia: hyperadrenocorticism, hyperthy-

roidism, feline symmetric alopecia, demodicosis, dermatophytosis, alopecia

areata, telogen effluvium/defluvium, skin fragility syndrome, alopecia mucinosa,

epitheliotropic lymphoma, erythema multiforme (idiopathic and herpes virus

associated), sebaceous adenitis

Exfoliative dermatitis associated with thymoma: demodicosis, dermatophytosis,

hyperadrenocorticism, epitheliotropic lymphoma, erythema multiforme (idio-

pathic and herpes virus associated), drug reaction, hypersensitivity reaction, sys-

temic lupus erythematosus, FeLV or FIV-related dermatitis.

DIAGNOSTICS

 CBC/biochemistry/urinalysis: depends upon specific condition and involvement of

other organ systems.

 Elevated plasma glucagon levels: consistently noted with glucagon-secreting pancre-

atic or extrapancreatic neoplasia and hypoaminoacidemia (notably glutamine, pro-

line, cysteine, hydroxyproline) in superficial necrolytic dermatitis.

 Cytology of lesions: rarely definitive; pattern of cellular aggregation significant to

determination of cause.

 Imaging: depends upon specific condition and involvement of other organ systems.

 Dermatohistopathology required for diagnosis; immunohistochemical studies from

tissues may be required to distinguish nonmalignant from malignant cell populations.

 Ultrasonography: pathognomonic “Swiss cheese” hepatic appearance with superficial

necrolytic dermatitis; pancreatic mass and/or nodular lesions in the liver or peritoneal

cavity with pancreatic/hepatic paraneoplastic alopecia; mediastinal mass in exfoliative

dermatitis associated with thymoma.

 Thoracic radiographs: metastatic lesions in the lungs or pleural cavity in pancre-

atic/hepatic cases.

 CT scans.

 Laparoscopy or exploratory laparotomy: identify primary and metastatic tumors.