myeloid neoplasia

• Myeloid leukemia can be acute (immature cells) or chronic (differentiated cells)

  • Chronic cases have polycythemia vera (erythrocyte overproduction)
• Mast cells are a form of granulocyte so it can be normal to see them in reactive lymph nodes.

  • Malignant transformation causes MCT

  MCTs usually affect older dogs but any age at risk and they present as skin masses.

  • Common-up to 20% of all canine skin tumors

  Cytology is very sensitive so always FNA skin masses you think could be a MCT. Some breeds are more susceptible such as boxers, Labradors, golden retrievers, Staffordshire bull terriers, Boston terriers and pugs
• examples of myeloid neoplasia are mast cell tumours, histiocytomas and transmissible venereal tumours
• Histiocytomas are a common neoplasm in small animal practice that typically affects young dogs (under 2 years typically but also includes any dog that isn't geriatric) and is classically benign. It can regress independently over several weeks, but use caution when advising clients, as they can look more unpleasant as they regress (crack and bleed)

  • Mast cell tumor can look a lot like histiocytom,a so offer to FNA and inform owners it may be a MCT if no regression occurs

  However,  not all regress and can be surgically remove if concerned about location