Carcinoma of the submandibular salivary glands with multiple metastases in a cat

External beam radiotherapy for the treatment of feline salivary gland carcinoma: six new cases and a review of the literature

CASE SERIES SUMMARY

Salivary gland carcinoma is uncommon in cats. We report the outcome of radiation therapy in six cases (four salivary gland adenocarcinomas, one tubulopapillary adenocarcinoma, one carcinoma). Five were treated after surgical excision of the primary tumour, but four had gross disease (primary or metastatic) at the time of starting radiotherapy. Exact progression-free interval from the start of radiotherapy in the two cats where this was known was 120 and 144 days, respectively. One cat was signed off at 766 days with no evidence of recurrence. Another cat was in remission at 202 days (when last seen by the referring practice) but subsequently developed recurrence (date uncertain). Survival time was known for three cats (55 days, 258 days and 570 days from initiation of radiotherapy, respectively). In two cases, locoregional progressive disease (PD) was confirmed, and the other presumed as the cause of death. Two cats, known to have developed PD, were alive at the time of writing (at 206 and 549 days, respectively). No cat died as a result of distant metastatic disease.

RELEVANCE AND NOVEL INFORMATION

There is a paucity of information on the treatment of salivary gland tumours. In humans, as in cats, there is no optimised standard of care for malignant tumours. It is accepted that, for surgical candidates (even with large tumours), surgery and radiotherapy is superior to radiotherapy alone. However, the benefits of postoperative radiotherapy compared with surgery alone are only clear in patients with high-risk tumours (ie, those with large and invasive primary tumours, close or incomplete margins, high histopathological grade, histological evidence of neural or vascular invasion, or positive lymph nodes). This population is analogous to the population reported here, and likely to most cats presented in practice. Thus, radiation therapy may help improve locoregional control and survival in cats.

Parotid gland adenocarcinoma in a cow: case report

ABSTRACT A 9-year-old Girolando dairy cow, weighing 400kg, with a history of increased volume in the right parotid region, which extended to the submandibular region, was assisted. Fine needle aspiration cytology was performed, and the cytological findings were consistent with malignant neoplasm of epithelial origin (carcinoma). Because of the unfavorable prognosis, the animal was euthanized and submitted to an anatomopathological examination. Samples of the increased parotid and affected lymph nodes were collected for histopathological evaluation. The microscopic changes were accentuated features of anaplasia, moderate cell proliferation, atypical mitotic figures, and necrosis. Stroma ranged from delicate to scirrhous, and the tumor boundaries were not distinct. These findings substantiated the preliminary histomorphological diagnosis of undifferentiated carcinoma with metastasis in lymph nodes. Immunohistochemical tests were performed with anti-CK Pan (clone AE1AE3), anti-CK HMW (clone 34βE12), anti-CK19 (clone RCK108), anti-vimentin (clone V9), anti-S100 (polyclonal), and anti-androgen (polyclonal) antibodies. The immunophenotype favored the diagnosis of salivary gland adenocarcinoma. Despite the rareness in cattle, salivary gland adenocarcinoma should be considered in the differential diagnosis of diseases that occur with increased volume in the head, lymphadenopathy, drooling, dysphagia, and progressive weight loss.

Atypical vimentin expression in a feline salivary gland adenocarcinoma with widespread metastases

We report herein a feline salivary gland adenocarcinoma with widespread metastases to draining lymph nodes, liver and lung, as well as an unusual metastasis to the spleen. Histologically, the primary salivary gland tumor consisted of low columnar to polygonal epithelial cells forming tubules and trabeculae. The spleen was infiltrated with sheets of poorly differentiated large round cells. Interestingly, morphologic change in epithelial cells was accompanied with the acquisition of vimentin intermediate filaments, a feature particularly evident in the splenic metastasis. This study highlights the role of epithelial cell plasticity during carcinogenesis and metastasis.

Nasal acinic cell carcinoma in a cat

This case report describes the clinical, magnetic resonance imaging (MRI)-related, and pathologic features of a nasal acinic cell carcinoma in a cat. A 16-year-old, castrated male, oriental shorthaired cat, weighing 3.8 kg, was presented with history of sneezing, coughing, and nasal discharge persisting several months. Evaluation by MRI revealed an heterogeneous, space-occupying lesion that filled the left nasal cavity and was diagnosed by histopathologic examination as an acinic cell carcinoma arising from a minor salivary gland of the nasal cavity. Acinic cell carcinoma is a rare tumor in veterinary medicine. The tumor is composed mainly of cells resembling serous cells of salivary glands and originates from major or minor salivary glands. Clinicians and pathologists should be aware of the occurrence of acinic cell carcinoma in the sinonasal tract and include the tumor in the differential diagnosis of feline nasal diseases.