Scleromyxedema-like Syndrome With Systemic Involvement in a Cat

Abstract

Scleromyxedema-the generalized form of lichen myxedematosus, a primary mucinosis-is a rare disease in human patients. It is characterized by dermal mucin deposits, increased numbers of fibroblasts, and variable fibrosis in the absence of thyroid disease. It is accompanied in 80% of cases by a monoclonal gammopathy. To date, scleromyxedema with systemic involvement has not been documented in domestic animals. This is the first report of a scleromyxedema-like syndrome in a cat, which had a substantial deposition of mucin in the dermis of the head and paws with a mild gammaglobulinemia of 2.25 g/dl (reference range, 1.39-2.22 g/dl). At necropsy, multiple nodules of connective tissue intermingled with mucin deposits were conspicuous on the surface of thoracic and abdominal organs. Such severe systemic accumulations of mucin have not been reported in human or veterinary medicine.

Scleromyxoedema in a dog

“…Thyroid disease was excluded and a mild hyperglobulinemia was present. The disease progressed rapidly and, at postmortem examination, fibromyxoid serosal masses involved several organs . A dog with generalized papular mucinosis, cutaneous oedema and a monoclonal gammopathy was reported as a part of a case series .…”

“…Reports of other mucinoses are limited . Scleromyxoedema was well described in a cat with scleromyxoid skin thickening of the head and limbs along with supportive histopathology . Thyroid disease was excluded and a mild hyperglobulinemia was present.…”

“…5,11,12 Scleromyxoedema was well described in a cat with scleromyxoid skin thickening of the head and limbs along with supportive histopathology. 4 Thyroid disease was excluded and a mild hyperglobulinemia was present. The disease progressed rapidly and, at postmortem examination, fibromyxoid serosal masses involved several organs.…”

“…The disease progressed rapidly and, at postmortem examination, fibromyxoid serosal masses involved several organs. 4 A dog with generalized papular mucinosis, cutaneous oedema and a monoclonal gammopathy was reported as a part of a case series. 5 The clinical signs, gammopathy, and presence of mucin and 2 Cutaneous lichen myxoedematosus is not well described in domestic animals.…”

“…In the cutaneous form of lichen myxoedematosus, lesions, which can be localized or generalized, are restricted to the skin . The veterinary literature contains a single description of scleromyxoedema in a cat and one dog reported as having papular mucinosis . This report describes a dog with scleromyxoedema with generalized papules and nodules, classic histology, progressive arthropathy and systemic decline.…”