Clinicopathological features of seven cases of canine myelofibrosis and the possible relationship between the histological findings and prognosis

Abstract

Seven dogs with non-regenerative anaemia were diagnosed as having myelofibrosis on the basis of the presence of collagen and increased deposits of reticulin fibre in the haemopoietic spaces of bone marrow core biopsies. A scoring system was used to assess the cellularity of the marrow and the amounts of collagen, reticulin and haemosiderin present. These scores, together with the haematological findings, were compared with the dogs' responses to treatment and their outcome. Treatment consisted of blood transfusions, where required, and anabolic steroids and corticosteroids. Three dogs deteriorated and were euthanased within three months of diagnosis, but the other four recovered fully. There was no correlation between the collagen and reticulin scores, or the degree of anaemia and the outcome, but the four dogs which recovered all had a macrocytosis when first examined. There was no evidence of an underlying lymphoproliferative or myeloproliferative disease in any of the seven cases.

Histologic and cytologic bone marrow findings in dogs with suspected precursor‐targeted immune‐mediated anemia and associated phagocytosis of erythroid precursors

“…This aligns with previous reports of reticulin or collagen myelofibrosis in dogs with suspected immune‐mediated anemia, and with reports of Coombs’‐positive or corticosteroid‐responsive anemia in some dogs with severe myelofibrosis . The mechanism of fibrosis in these dogs is unknown, but, as has been suggested by others, it may be similar to that of autoimmune myelofibrosis reported in human patients with such conditions as systemic lupus erythematosus and autoimmune hemolytic anemia . Alternatively, myelofibrosis in PIMA dogs may be related to a chronic inflammatory state within the bone marrow itself …”

Bone Marrow Cytologic and Histologic Biopsies: Indications, Technique, and Evaluation

“…This is considered a secondary response and may be reversible. 26 In both necrosis and myelofibrosis, bone marrow aspirates often contain particles with low cellularity, much blood contamination, and occasional fibrocytes present. For this reason, a core biopsy sample obtained concurrently with the aspirate biopsy is necessary for confirmation of these conditions.…”

Extramedullary Hematopoiesis: A New Look at the Underlying Stem Cell Niche, Theories of Development, and Occurrence in Animals

“…39,40 Two case series of dogs diagnosed antemortem with presumed primary myelofibrosis have been described. 40,114 In another case series of female Beagle dogs with myelofibrosis, EMH was found in liver and spleen at necropsy. 89 A case of idiopathic myelofibrosis was reported in a male marmoset in which trilineage EMH was found throughout the intestinal serosa.…”