Malignant Pilomatricoma in a young canine with pelvic invasion and pulmonary metastasis

A 3.5-year-old, castrated male Soft Coated Wheaten Terrier was referred to the University of Pennsylvania for evaluation of 1-2 month history of mild lameness and fecal incontinence. Physical examination revealed pain on lumbosacral manipulation, hyperreflexia in all 4 limbs and lack of anal tone. MRI of the area revealed a large (~6cm diameter) mass invading and expanding the pelvic bones, sacrum, vertebrae, vertebral canal, associated nerves, musculature and subcutaneous tissues. No other abnormalities were noted on MRI. Osteosarcoma was considered the primary differential. A fine needle aspirate was performed. The smears were highly cellular, containing many neoplastic cells with very high nuclear to cytoplasmic ratio, rare spindle cells, and rare inflammatory cells amid a background containing moderate amounts of blood. Neoplastic cells were 12-16um in diameter, round to cuboidal in shape and present both individually and in small cohesive clusters. Nuclei were round (rarely oval) and basally located with lacy to coarse chromatin and 1-3, small, round, deeply basophilic nucleoli. Cytoplasm was lightly to moderately basophilic, scant in amount and often had irregular cytoplasmic blebbing. Criteria of malignancy included moderate anisokaryosis and anisocytosis with the presence of multiple, prominent nucleoli. Given the location, signalment and cytologic findings, differentials included a primitive embryonal tumor (e.g. neuroblastoma or nephroblastoma in an atypical location) or poorly differentiated carcinoma. The owner elected euthanasia due to the poor prognosis. Necropsy confirmed the pelvic mass and revealed it to be light gray-white and gritty on cut section. The paired iliac lymph nodes were of normal size, yet multiple, firm, pale pink-tan nodules were noted in the lung which when sectioned were white-tan and soft to friable. Histologically, the lung masses and pelvic mass were identical. The masses were composed of irregular islands, lobules, and nests of basaloid cells. Neoplastic basaloid cells were often seen transistioning abruptly into large lakes of “ghost” cells with concurrent areas of ossification or calcification. The abrupt transistioning and concurrent ossification are considered distinct features of pilomatricomas. Conclusion: The young age of the dog, the invasiveness of the tumor, the cytologic appearance of the neoplastic cells (cytoplasmic blebbing) and the lack of keratinized “ghost” cells on aspirate are unusual features of this case. Malignant pilomatricomas are a very rare neoplasm with only six reports in the veterinary literature; however, they should be included as a differential diagnosis for invasive subcutaneous masses with a predominant population of high nuclear to cytoplasmic ratio neoplastic epithelial cells

Malignant pilomatricoma in a soft-coated Wheaten Terrier

A 3-year-old, castrated male, soft-coated Wheaten Terrier was presented for evaluation of mild lameness, fecal incontinence, lumbosacral pain, and lack of anal tone. Magnetic resonance imaging scan showed a large (8 × 6 × 5 cm) mass invading and expanding the pelvic bones, sacrum, and associated structures. A fine-needle aspirate of the mass contained many neoplastic cells with high nuclear to cytoplasmic ratios and rare spindle and inflammatory cells. The neoplastic cells were 12-16 μm in diameter, round to cuboidal, basaloid in appearance, and arranged both individually and in loosely cohesive clusters with variably distinct cell borders. Given the location, signalment, and cytologic findings, differential interpretations included a primitive embryonal tumor (eg, neuroblastoma or nephroblastoma in an atypical location) or poorly differentiated carcinoma. The owner elected euthanasia due to the poor prognosis. Abnormal gross findings on necropsy included the pelvic mass and multiple firm, pale, pink-tan nodules in the lung, which proved to be metastases. On histologic examination, the mass and nodules were composed of irregular islands, lobules, and nests of basaloid cells, which transitioned abruptly into large lakes of "ghost" cells with areas of ossification and calcification, consistent with a diagnosis of malignant pilomatricoma. This unusual presentation of a pilomatricoma adds to our knowledge of expected cytologic findings for this tumor

Causes of mortality in backyard poultry in eight states in the United States

A comprehensive understanding of common diseases of backyard poultry flocks is important to providing poultry health information to flock owners, veterinarians, and animal health officials. We collected autopsy reports over a 3-y period (2015-2017) from diagnostic laboratories in 8 states in the United States; 2,509 reports were collected, involving autopsies of 2,687 birds. The primary cause of mortality was categorized as infectious, noninfectious, neoplasia or lymphoproliferative disease, or undetermined. Neoplasia or lymphoproliferative disease was the most common primary diagnosis and involved 42% of the total birds autopsied; 63% of these cases were diagnosed as Marek's disease or leukosis/sarcoma. Bacterial, parasitic, and viral organisms were commonly detected, involving 42%, 28%, and 7% of the birds autopsied, respectively, with 2 or more organisms detected in 69% of birds. Our findings demonstrate the importance of educating flock owners about disease prevention and biosecurity practices. The detection of zoonotic bacteria including paratyphoid salmonellae, Campylobacter spp., Listeria monocytogenes, and Mycobacterium avium, and the detection of lead and other heavy metals, indicate public health risks to flock owners and consumers of backyard flock egg and meat products