Thyroid abscess associated with thyrotoxicosis caused by Yersinia enterocolitica subsp. palearctica in a patient with follicular adenoma of the thyroid gland.

BACKGROUND: Yersinia enterocolitica is a gram-negative zoonotic bacterial pathogen that is typically transmitted via the fecal-oral route. The most common clinical manifestation of a Y. enterocolitica infection is self-limited gastroenteritis. Although various extraintestinal manifestations of Y. enterocolitica infection have been reported, there are no reports of thyroid abscesses. CASE PRESENTATION: An 89-year-old Japanese man with follicular adenoma of the left thyroid gland was admitted to our hospital with a 2-day history of fever and left neck pain. Laboratory tests revealed low levels of thyroid stimulating hormone and elevated levels of free thyroxine 4. Contrast-enhanced computed tomography showed low-attenuation areas with peripheral enhancement in the left thyroid gland. He was diagnosed with thyroid abscess and thyrotoxicosis, and treatment with intravenous piperacillin-tazobactam was initiated after collecting blood, drainage fluid, and stool samples. The isolated Gram-negative rod bacteria from blood and drainage fluid cultures was confirmed to be Y. enterocolitica. He was diagnosed with thyroid abscess and thyrotoxicosis due to be Y. enterocolitica subsp. palearctica. The piperacillin-tazobactam was replaced with levofloxacin. CONCLUSION: We report a novel case of a thyroid abscess associated with thyrotoxicosis caused by Y. enterocolitica subsp. palearctica in a patient with a follicular thyroid adenoma.

Cervical ganglioneuroblastoma in a new born Japanese Black calf.

This case report describes a congenital ganglioneuroblastoma in a 38-day-old male Japanese Black calf. The cervical multinodular mass was present at birth and grew rapidly. The cut surface was pale gray-to-yellow and had a gelatinous appearance. Hemorrhagic cysts of various sizes were observed in the nodule. Histologically, the mass contained clusters of neuroblastic cells, ganglionic cells, and Schwann-like cells. Immunohistochemically, the ganglionic cells showed strong positivity for neuron-specific enolase, neurofilament, synaptophysin, and chromogranin A, whereas the Schwann-like cells strongly expressed S-100, glial fibrillary acidic protein, and vimentin. Ultrastructurally, neurosecretory granules resembling catecholamine were observed in the neuroblastic and Schwann-like cells. Based on the pathology, the diagnosis was congenital cervical nodular ganglioneuroblastoma.

Subcutaneous rhabdomyosarcoma in an old rabbit.

An 11-year-old castrated male rabbit presented with a subcutaneous mass in the right hind limb. The mass comprised solid and myxoid areas. Solid areas were characterized by a storiform or interlacing pattern of spindle cells, strap cells, multinucleated giant cells and round cells with eccentrically located nuclei, whereas the myxoid areas were composed predominantly of elongated fusiform cells with hyperchromatic nuclei embedded in Alcian Blue-positive myxoid stroma. Immunohistochemically, tumor cells in both areas were positive for desmin and vimentin. Ultrastructurally, the tumor cells in the solid areas had abundant myofilaments with electron dense Z-band structures. Based on these pathological findings, this case was diagnosed as rhabdomyosarcoma in a rabbit.

Congenital lobar emphysema concurrent with pneumothorax and pneumomediastinum in a dog.

A two-year-old castrated male Pomeranian dog was referred with the chief complaints of coughing and subcutaneous emphysema. On physical examination, the crepitant areas were palpable. When auscultated, the right chest was absent of respiratory sound, while the sound of the opposite side was enhanced. Radiographs presented pneumothorax and pneumomediastinum. On computed tomography, hypoattenuated bulla-like lesion at right middle lung lobe and trapped air in mediastinum were shown. After patient stabilization, surgery for excision of affected lobe was performed. During follow-up period, there were no recurrence and complication on radiographic examination. Based on clinical and pathological findings, the dog was diagnosed as congenital lobar emphysema.

The co-existence of a myxoid liposarcoma and leiomyoma in the same ovarian mass of a dog.

A 15-year-old, female mixed-breed dog presented with abdominal distention. An exploratory laparotomy revealed a large left ovarian mass (20 × 15 × 12 cm). Histopathological examination of the mass revealed a mixed myxoid liposarcoma and a well-differentiated leiomyoma. Four months after surgical removal of the mass, the dog died due to multiorgan metastasis. The metastasis was composed solely of the liposarcoma component. The liposarcoma component was Alcian Blue- and Oil red O-positive, and demonstrated immunoreactivity with S-100, adipophilin and vimentin. Electron microscopy revealed that the tumor cell cytoplasms were packed with lipid vacuoles and dilated rough endoplasmic reticulum. To our knowledge, this is the first report of myxoid liposarcoma and leiomyoma co-existing in a canine ovary.

Malignant epithelioid schwannoma of the oral cavity in a cat.

A malignant epithelioid schwannoma of the oral cavity was diagnosed in an 8-year-old domestic short-hair cat. The mass was located in the gingiva of the upper left premolar to molar region and showed multinodular growth patterns. The mass comprised epithelioid cells arranged in densely packed sheets. Tumor cells had large, round to oval nuclei with prominent nucleoli and an abundant eosinophilic cytoplasm. Immunohistochemically, most of the tumor cells were positive for S-100 protein, glial fibrillary acidic protein and vimentin, but all lacked melanoma-associated antigen and muscle and neuroendocrine markers. Stains for type IV collagen showed linear immunoreactivity around single cells and groups of cells. Ultrastructurally, tumor cells were separated by a well-defined basement membrane, and interdigitating cell processes were observed. To our knowledge, this is the first report of feline malignant epithelioid schwannoma.

A canine case of primary intra-right atrial paraganglioma.

An 11-year-old mixed breed dog was presented with signs of anorexia. Radiographic and ultrasound examinations revealed a large mass in the heart, between the right atrium and the right ventricle. Upon gross inspection, a multilobulated tumor arising from the right atrial wall and occupying the right atrium was identified. Microscopical analysis demonstrated that this tumor consisted of neoplastic cells with granular cytoplasm, which were separated into nests by fine fibrovascular stroma and were negative for Grimelius's method. Immunohistochemical examinations revealed that the neoplastic cells expressed chromogranin A, synaptophysin and neuron specific enolase. Electron microscopy revealed that the cytoplasm of the neoplastic cells held secretory granules. Based on these pathological findings, the tumor was diagnosed as a paraganglioma. This report is a rare case of primary paraganglioma deriving from the right atrium and provides a detailed characterization of its morphological features.

A case report of feline pituitary carcinoma with hypercortisolism.

Feline pituitary tumors are rare. An 8-year-old male Japanese domestic cat presented with anorexia and emaciation. The cat died 17 days after admission from progressive neurological symptoms. At necropsy, a pituitary tumor measuring 25 × 18 × 15 mm was found. Microscopically, the tumor was divided into multiple lobules and had grown invasively into the adjacent brain tissue and sphenoid bone. Tumor cells had pleomorphic nuclei with prominent centrally located nucleoli and abundant amphophilic polygonal cytoplasm. Immunohistochemically, the tumor cells stained with anti-adrenocorticotropic hormone (ACTH), α-melanin-stimulating hormone (MSH) and ß-endorphin antibodies. Ultrastructurally, the cytoplasm of the tumor cells contained various sized secretory granules. Based on these pathological findings, this tumor was diagnosed as pituitary carcinoma originated from pars intermedia cells.