Hyperoestrogenism and mammary adenosis associated with a metastatic Sertoli cell tumour in a male Pekingese dog

Occurrence of mammary gland tumours in male dogs and its weak association with development of testicular tumours: a review

Mammary gland tumours (MGTs) are commonly occurring neoplasms in female dogs. However, rare cases of MGTs in male dogs have been reported for years. Due to the low incidence of MGTs in male dogs in comparison to female dogs, veterinary oncology is mainly focused on mammary neoplasms diagnosed in female dogs and extensive research is conducted in this scientific area. Therefore, there are no sufficient epidemiological data on male dogs and the aetiology of their tumour development is still poorly understood.The aim of this literature review was to present cases of MGTs in male dogs for better understanding the scale of the problem over the years. The analyses of 74 affected male dogs with 92 tumours showed that the majority of MGTs in male dogs were benign tumours (54.3%), especially in form of adenomas, often developed in posterior canine mammary glands (58.1%).The increased number of canine MGTs in male dogs aged 7 -13 years with an age peak at 11 years was noted. The age of affected animals was not related to breed. Mammary gland neoplasms were diagnosed predominately in Crossbreeds (20.2%) followed by Cocker Spaniels (18.9%) and German Shepherds (10.8%).The association between MGT development in male dogs and co-occurrence of testicular tumours (TTs) has been discussed for years. Thus, cases of development of both tumours were included in this study. As a result, only in 12.7% cases of MGTs also history of TTs was described. Therefore, no general association between these tumours should be assumed.

Outcome of dogs with bone marrow suppression secondary to Sertoli cell tumour

Sertoli cell tumours are one of the most common canine testicular neoplasia. These tumours are significantly more likely to arise in cryptorchid dogs and are often functional, oestrogen-secreting tumours which can lead to fatal myelotoxicity. The goal of this study was to describe the outcome of dogs with oestrogen-induced bone marrow suppression secondary to Sertoli cell tumours in seven client-owned dogs. Medical records from April 1, 2011 through April 1, 2021 were reviewed to identify dogs that underwent surgical management of a Sertoli cell tumour with documented bone marrow suppression. Overall, 5/7 dogs required transfusion of blood products peri-operatively. Cases 1 and 6 received a transfusion of packed red blood cells (RBC) prior to surgery and case 5 required a transfusion of whole blood. Case 1 also required a transfusion of platelets before surgery. Post-operatively, cases 1 and 2 received packed RBC's and case 6 received two transfusions of whole blood. Case 3 required transfusions of both fresh frozen plasma and platelets post-operatively. All dogs survived to discharge and 6/7 dogs had documented improvement in haematopoietic values. Two dogs remained chronically thrombocytopenic. The median hospital stay was 4 days. One dog died within 4 weeks of surgery from worsening pancytopenia. Survival for greater than 1 year was documented in 4/7 dogs, and one dog was lost to follow-up 4 months post-operatively. One dog remained severely pancytopenic 4 weeks post-operatively and received oral lithium treatment. Improvements in all blood cell lines were observed within the 4 weeks and resolution of pancytopenia within 6 weeks. Historically, the prognosis for dogs with bone marrow suppression secondary to Sertoli cell tumours was guarded to poor. This report documented improved outcomes for dogs that underwent surgery, including one dog that received lithium chloride as treatment for Sertoli cell tumour-induced bone marrow suppression.