Diagnosis and Treatment of Anaplastic Mammary Carcinoma in a Sugar Glider (Petaurus breviceps)

Pathological and Immunohistochemical Findings of Disseminated Histiocytic Sarcoma in a Sugar Glider (Petaurus breviceps)

A 6-year-old intact female sugar glider (Petaurus breviceps) had a swelling at the pouch region and died 8 days after presentation. At necropsy, the urinary bladder and abdominal lymph nodes were enlarged and a mass was located in the pericloacal region. Tumour infiltration was also observed in the medial iliac lymph nodes, liver, spleen, small intestine, uterus and left ovary. Histopathologically, the tumours were composed of pleomorphic histiocytes that had round or bizarre nuclei and abundant pale eosinophilic cytoplasm. Immunohistochemically, tumour cells were positive for ionized calcium-binding adaptor molecule 1 and human leukocyte antigen and negative for CD3, B lymphocyte antigen 36 and cytokeratin. Histopathological and immunohistochemical examinations confirmed a diagnosis of disseminated histiocytic sarcoma. This neoplasm has not been previously reported in a sugar glider.

From humans to hydra: patterns of cancer across the tree of life

Cancer is a disease of multicellularity; it originates when cells become dysregulated due to mutations and grow out of control, invading other tissues and provoking discomfort, disability, and eventually death. Human life expectancy has greatly increased in the last two centuries, and consequently so has the incidence of cancer. However, how cancer patterns in humans compare to those of other species remains largely unknown. In this review, we search for clues about cancer and its evolutionary underpinnings across the tree of life. We discuss data from a wide range of species, drawing comparisons with humans when adequate, and interpret our findings from an evolutionary perspective. We conclude that certain cancers are uniquely common in humans, such as lung, prostate, and testicular cancer; while others are common across many species. Lymphomas appear in almost every animal analysed, including in young animals, which may be related to pathogens imposing selection on the immune system. Cancers unique to humans may be due to our modern environment or may be evolutionary accidents: random events in the evolution of our species. Finally, we find that cancer‐resistant animals such as whales and mole‐rats have evolved cellular mechanisms that help them avoid neoplasia, and we argue that there are multiple natural routes to cancer resistance.