Squamous cell carcinoma of unknown primary origin in a dog presenting with bone metastasis

Abstract

A 10-year-old female American Pit Bull dog was diagnosed with metastatic undifferentiated carcinoma of the scapula. Immunohistochemistry showed positive immunoexpression for cytokeratins (AE1/AE3, 34BE12, CK7) and vimentin, confirming squamous cell carcinoma. No evidence of nodules was found in the complete physical examination and imaging procedures conducted. The patient was diagnosed with carcinoma of unknown primary origin. Amputation and adjuvant chemotherapy with doxorubicin and piroxicam were performed, but the patient died of respiratory failure after 737 days of diagnosis. Necropsy confirmed undifferentiated carcinoma infiltrating the lungs and kidneys, and showing the same immunoexpression as the tumor in the scapula. Amputation associated with chemotherapy extended the overall survival time of this patient.

Presumed disseminated carcinomatosis of the bone marrow in a dog

“…The patient in this case was diagnosed with skeletal metastatic adenocarcinoma, but the primary tumour was not identified in the most common organs (lung, liver, kidneys, bladder and prostate) that metastasise to the skeletal system using multiple imaging techniques. In human medicine an algorithm is used for MCUP diagnosis using an immunohistochemical profile providing information on the neoplasm origin and helping in the treatment selection 7. An MCUP has been previously described in the scapula of a dog 7.…”

“…In human medicine an algorithm is used for MCUP diagnosis using an immunohistochemical profile providing information on the neoplasm origin and helping in the treatment selection 7. An MCUP has been previously described in the scapula of a dog 7. The authors used an immunohistochemical panel with antibodies which although not validated in canines was interpreted as supporting a diagnosis of a metastatic squamous cell carcinoma 7.…”

“…7 An MCUP has been previously described in the scapula of a dog. 7 The authors used an immunohistochemical panel with antibodies which although not validated in canines was interpreted as supporting a diagnosis of a metastatic squamous cell carcinoma. 7 In the present study neoplastic cells stained positive with a pancytokeratin antibody and negative with vimentin, supporting an epithelial origin.…”

“…7 The authors used an immunohistochemical panel with antibodies which although not validated in canines was interpreted as supporting a diagnosis of a metastatic squamous cell carcinoma. 7 In the present study neoplastic cells stained positive with a pancytokeratin antibody and negative with vimentin, supporting an epithelial origin. Further, the arrangement of some of the neoplastic cells in tubules was suggestive of an adenocarcinoma.…”

Cancer of unknown primary in a mare: case report and comparative pathology review

“…Based on clinicopathologic findings followed by IHC panel results, a diagnosis of disseminated adenocarcinoma of unknown primary site with peritoneal and pleural carcinomatosis was established for this mare. Such a presentation is uncommon in horses; cancers originating from the kidney, 18,19 stomach, 17 and bile ducts 5,16 are the predominant reported sites of origin.…”