Clinical, histological and immunophenotypic findings in a mare with a mammary lymphoma associated with anaemia and pruritus

Abstract

Summary An 18‐year‐old Quarter Horse mare presented with an 18 week history of dermatological lesions characterised by recurrent urticaria and recent signs of enlarged mammary glands, pyrexia, alopecia and intense pruritus. Haematological and serum biochemical analyses revealed anaemia, leucocytosis, thrombocytopenia and hyperfibrinogenaemia. Mammary discharge was evaluated and revealed neutrophilia. Cytological examinations of fine needle aspirates from the parotid lymph nodes were normal. Common causes of anaemia were ruled out by specific tests. The initial diagnosis was mastitis and 2 weeks later the animal returned to the hospital with worsening of clinical signs, intermittent fever, intense pruritus and generalised alopecia. Blood samples were collected for haematological and serum biochemical analyses, and the mammary gland and parotid lymph nodes were biopsied. Rectal palpation revealed a large irregular mass near the left kidney with adhesions of surrounding structures. The animal died before the laboratory results were ready. This report details the clinical, histological and immunophenotypic findings of a case of large lymphoma in a mare.

Paraneoplastic syndromes

“…2005). These, along with the case report of Mendes et al . (2011), highlight the importance of a thorough clinical work‐up, as neoplasia should be considered as a differential diagnosis for any collection of clinical signs.…”

“…Paraneoplastic syndromes may precede the detection of an active malignancy, and thorough investigation is therefore warranted to determine the cause of any clinical sign whose cause is not immediately apparent. Mendes et al (2011) present an unusual case of pyrexia, anaemia and pruritus associated with a mammary neoplasm in an 18-year-old horse. Interestingly, mammary tumours are one of the more common causes of paraneoplastic syndromes in humans.…”

“…Mendes et al . (2011) present an unusual case of pyrexia, anaemia and pruritus associated with a mammary neoplasm in an 18‐year‐old horse.…”

Equine mammary gland disease with a focus on botryomycosis: A review and case study

“…Further, histiocytomas and lymphomas have been reported (Reesink et al . 2009; Shank 2009; Mendes et al . 2011).…”

“…Melanoma occurs in the udder with some frequency and these are often embedded within the glandular tissue; most are benign and well demarcated but occasionally they can be malignant, large and invasive (Knottenbelt 2003;Bader and Busch 2006). Further, histiocytomas and lymphomas have been reported (Reesink et al 2009;Shank 2009;Mendes et al 2011). However, neither melanoma, histiocytoma nor lymphoma are genuine mammary tumours.…”