Page 1485 - Cote clinical veterinary advisor dogs and cats 4th

756.e2 Paraneoplastic Syndromes, Cutaneous

Paraneoplastic Syndromes, Cutaneous Client Education
Sheet
VetBooks.ir

BASIC INFORMATION
fissured footpads; erythema; scale; ± dehydra-
tion, emaciation and overdiagnosis of these syndromes. Diag-
nosis of the different cutaneous paraneoplastic
Definition • Exfoliative dermatitis: nonpruritic, scaling syndromes is confirmed with skin biopsy
Uncommon non-neoplastic skin lesions serve dermatitis on pinnae, head, generalized; and dermatohistopathologic evaluation. The
as markers for internal neoplasia. variable alopecia; brown, waxy deposits histologic diagnosis of the skin lesions suggests
around mucocutaneous areas, nail beds; which underlying metabolic derangement or
Synonyms variable erythema internal neoplasm to pursue as the cause of the
Exfoliative dermatitis, nodular dermatofibro- • Nodular dermatofibrosis: nonpainful, firm paraneoplastic disorder.
sis, paraneoplastic alopecia, paraneoplastic cutaneous nodules on extremities and on
pemphigus the head, neck, and ventral trunk Differential Diagnosis
• Paraneoplastic pemphigus: depressed attitude; • Paraneoplastic alopecia: demodicosis, derma-
Epidemiology ulcers and erosions of the oral mucosa, tophytosis, endocrine (hyperadrenocorticism,
SPECIES, AGE, SEX mucocutaneous junctions, haired skin hyperthyroidism, hypothyroidism), immune
• Paraneoplastic alopecia: older cats (7-16 mediated (alopecia areata), neoplasia, telogen
years) Etiology and Pathophysiology effluvium
• Exfoliative dermatitis: middle-aged to old • Paraneoplastic alopecia: pathogenesis may • Exfoliative dermatosis: demodicosis, infec-
cats involve cytokine production leading to tious agents (dermatophytosis, bacterial
• Nodular dermatofibrosis: middle-aged dogs atrophy of hair follicles; secondary Malas- infections, feline leukemia virus [FeLV]
(3-7 years) sezia overgrowth may contribute to excessive infection), hypersensitivities, cutaneous drug
• Paraneoplastic pemphigus: dogs, rare in cats grooming. reactions, autoimmune disorders, neoplasia
• Exfoliative dermatosis: tumor-induced, (cutaneous lymphoma)
GENETICS, BREED PREDISPOSITION immune-mediated process, possibly related • Nodular dermatofibrosis: primary cutaneous
Nodular dermatofibrosis: German shepherds, to erythema multiforme, has been suggested. neoplasms
autosomal dominant inheritance due to muta- • Nodular dermatofibrosis: collagen production • Paraneoplastic pemphigus: pemphigus
tion of the folliculin gene (FLCN) in the skin may be stimulated by growth vulgaris, bullous pemphigoid, systemic lupus
factors, transforming growth factor alpha erythematosus, erythema multiforme, toxic
ASSOCIATED DISORDERS (TGF-alpha) and TGF-beta, which are epidermal necrolysis, cutaneous lymphoma
• Paraneoplastic alopecia (cats): pancreatic produced by the renal tumors. Lesions
adenocarcinoma, bile duct carcinoma, develop separately through a common genetic Initial Database
hepatocellular carcinoma, metastatic intes- abnormality, or simultaneous fibrosis of the • CBC, serum biochemical panel, and
tinal carcinoma, neuroendocrine pancreatic skin and kidneys results in collagenous nevi urinalysis: nonspecific changes may be
neoplasia, hepatosplenic plasma cell tumor and renal outflow obstruction. noted.
• Exfoliative dermatitis (cats): thymoma; • Paraneoplastic pemphigus: cross-reactivity • FeLV and feline immunodeficiency virus
idiopathic cases reported between tumor antigen and self-antigen or (FIV) serologic testing is indicated for all
• Nodular dermatofibrosis (dogs): renal cyst- secretion of excessive immunostimulatory cats, but these neoplasms are not associated
adenocarcinomas/cystadenomas, polycystic cytokines may be involved. with seropositive status.
kidneys, concurrent uterine leiomyoma • Paraneoplastic alopecia
• Paraneoplastic pemphigus: dogs: thymic DIAGNOSIS ○ Dermatohistopathologic exam: hair
lymphoma, Sertoli cell tumor, mammary follicle and adnexal atrophy, epidermal
carcinoma, splenic sarcoma; cats: thymic Diagnostic Overview hyperplasia
lymphoma reported with concurrent The association between cutaneous lesions and ○ Cutaneous cytology: Malassezia overgrowth
myasthenia gravis internal neoplasia should be remembered but ○ Abdominal ultrasonography: liver or
not overinterpreted to avoid underdiagnosis pancreatic lesions due to neoplasia
Clinical Presentation
HISTORY, CHIEF COMPLAINT
• Paraneoplastic alopecia: progressive alopecia,
weight loss, lethargy. Alopecia may be noted
as the first manifestation (harbinger) of
internal neoplasia. Internal disease is often
advanced at the time of presentation, but
the chief complaint commonly relates to
alopecia.
• Exfoliative dermatitis: scaling dermatitis;
alopecia; brown, waxy deposits on the skin
• Nodular dermatofibrosis: cutaneous nodules
on the limbs, head
• Paraneoplastic pemphigus: anorexia, ptyalism,
erosive/ulcerative skin and mucosal lesions
PHYSICAL EXAM FINDINGS
• Paraneoplastic alopecia: nonpruritic, sym-
metrical alopecia on ventrum, legs, face, and PARANEOPLASTIC SYNDROMES, CUTANEOUS Paraneoplastic alopecia in a 14-year-old cat with
neck; glistening skin; fur epilates easily; dry, pancreatic adenocarcinoma. (Copyright Dr. Manon Paradis.)

www.ExpertConsult.com