Malignant histiocytosis in Cats (Felis) | Vetlexicon
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Malignant histiocytosis

ISSN 2398-2950

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Introduction

  • Very rare condition in cats. Fewer than 10 cases reported in literature.
  • Characterized by systemic proliferation of atypical tissue macrophages (histiocytes).
  • Erythrophagocytosis important characteristic of this disease.
  • Signs: anorexia, lethargy.
  • Diagnosis: biopsy.
  • Treatment: none effective.
  • Prognosis: grave.

Presenting signs

  • Anorexia.
  • Lethargy.
  • Anemia.

Age predisposition

  • Reported in adult cats.

Pathogenesis

Etiology

  • Unknown.

Predisposing factors

General

  • FeLV not involved.

Specific

  • None known.

Pathophysiology

  • Malignant neoplasm of tissue macrophages.
  • Rapid progression.
  • Characteristic features include presence of multi-nucleated giant cells and erythrophagocytosis.

Timecourse

  • Rapid progression, sick less than 1 week before presentation.

Diagnosis

Presenting problems

  • Anemia.
  • Inappetence.
  • Lethargy.

Client history

  • Inappetence.
  • Lethargy.

Clinical signs

  • Depression.
  • Pale mucous membranes.
  • Possible hepatosplenomegaly.
  • Lymphadenopathy.
  • Pyrexia.

Diagnostic investigation

Radiography

Ultrasonography

Histopathology

  • Biopsy can be useful and may be performed under ultrasound guidance.

Hematology

Biochemistry

  • Non-specific changes -may include hyperglycemia and hyperbilirubinemia.

Confirmation of diagnosis

Discriminatory diagnostic features

  • History.
  • Clinical signs.
  • Bone marrow evaluation.

Definitive diagnostic features

  • Biopsy of affected organs/bone marrow-presence of neoplastic histiocytes, plus erythrophagocytosis.

Histopathology findings

  • Infiltrate of affected organs by atypical histocytes.
  • Multinucleated giant cells and erythrophagocytosis present.

Differential diagnosis

Other causes of anemia

  • Osmotic fragility.

Treatment

Initial symptomatic treatment

Monitoring

Prevention

Outcomes

Prognosis

  • Grave: fatal disease. In the few reported cases, no response to therapy.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Kraje A C, Patton C S & Edwards D F (2001) Malignant histiocytosis in 3 cats. JVIM 15 (3), 252-256 PubMed.
  • Freeman L, Stevens J, Loughman C et al (1995) Clinical vignette - malignant histiocytosis in a cat. JVIM (3), 171-173 PubMed.
  • Court E A, Earnest-Koons K A, Barr S C et al (1993) Malignant histiocytosis in a cat. JAVMA 203 (9), 1300-1302 PubMed.

Other sources of information

  • Withrow S J and MacEwen E G (1996) Small Animal Clinical Oncology. W B Saunders. (Papers referring to canine histiocytic disease.)