ABSTRACT
A large, pedunculated cutaneous mass protruding from the left flank fold and an enlarged left prefemoral lymph node were found on examination of a 3-d-old crossbred Aberdeen Angus heifer. The calf was asymptomatic aside from peripheral lymphadenopathy, and the mass, along with the left prefemoral lymph node, was surgically excised. Histologic examination of the mass and the lymph node revealed a homogeneous population of neoplastic cells that stained positively with immunohistochemical stains S100 and melan A, supporting a diagnosis of congenital amelanotic melanoma with nodal metastasis. Two months later, the calf became acutely recumbent and was euthanized after clinical examination revealed widespread metastasis. Gross autopsy revealed widely disseminated metastases that involved vertebral bodies, spinal cord, heart, kidneys, lungs, oral mucosa, multiple lymph nodes, and the marrow cavity of several long bones. Our case serves as a reminder that, although rare, congenital neoplasms occur in bovids and have the potential for aggressive, metastatic behavior.
Subject(s)
Cattle Diseases/surgery , Melanoma, Amelanotic/veterinary , Skin Neoplasms/veterinary , Animals , Cattle , Cattle Diseases/congenital , Diagnosis, Differential , Fatal Outcome , Female , Lymph Nodes/surgery , Melanoma, Amelanotic/congenital , Melanoma, Amelanotic/surgery , Skin Neoplasms/congenital , Skin Neoplasms/surgeryABSTRACT
The broad spectrum of heat-related injury (HRI) and its associated lesions is well described in the human literature, with rare reports of similar findings in farm animals. In the current case series, lesions from 4 of 8 lambs that presented with clinical signs of heat stress are reported. Gross lesions at necropsy consisted of acute renal swelling and pallor in 2 of 4 lambs, muscle pallor in 2 of 4 lambs, and chronic bronchointerstitial pneumonia in each of the 4 lambs. Histological lesions considered heat-related included acute renal tubular necrosis, pigment casts, tubular epithelial regeneration, multifocal myocyte degeneration, necrosis, and dropout with histiocytic influx and regeneration. Chronic, bronchointerstitial pneumonia, present in each lamb, was considered a condition predisposing to HRI. Compatibility between observed lesions and those reported in human beings with injury secondary to elevated body temperatures established a diagnosis of HRI in these animals. Diagnostic pathologists should consider HRI in lambs with histological evidence of renal tubular necrosis and/or rhabdomyolysis and even in cases where the clinical picture is strongly suggestive but lesions are not demonstrable.
