Labrador with changed appearance

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THIS CASE WAS PROVIDED BY....... Elsevier Health Sciences - North and Banks, Small Animal Oncology

Signalment: 9-year-old male neutered Labrador Retriever

Chief complaint: for the last three months he had not been eating well at home and would not eat dry food so the clients had changed him to tinned food. Two weeks ago the clients noticed the change in him that led to this consultation.

Physical Examination:

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What did you find question, based on the photograph, when you examined this dog? Large mass on the maxilla causing facial deformity Swelling of the temporal muscles on the left side Muscle wasting over the entire head and face Muscle wasting of the temporal muscles on the right side Nothing: the dog looked normal Please select an option Incorrect. Look more closely at the photograph. Incorrect. Look more closely at the photograph. Incorrect. Look more closely at the photograph. Correct! Incorrect. Look more closely at the photograph.

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What cranial nerve innervates this muscle? Facial Trigeminal Abducens Hypoglossal Oculomotor Please select an option Incorrect. Review anatomy and choose again. Correct. Incorrect. Review anatomy and choose again. Incorrect. Review anatomy and choose again. Incorrect. Review anatomy and choose again.

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You examine the dog further and can feel a large mass located at the caudal part of the ramus of the mandible. When you open his mouth you see a large tumour. What is the most common oral tumour seen in the dog? Osteosarcoma Squamous cell carcinoma Malignant melanoma Amelioblastoma Fibrosarcoma Please select an option Incorrect. Review oral tumours and choose again. Incorrect. Review oral tumours and choose again. Correct. Incorrect. Review oral tumours and choose again. Incorrect. Review oral tumours and choose again.

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Based on your knowledge of oral tumours which of the above carries the best prognosis (i) and which carries the worst prognosis (ii)? (i) Amelioblastoma, (ii) fibrosarcoma (i) Squamous cell carcinoma, (ii) malignant melanoma (i) Fibrosarcoma, (ii) osteosarcoma (i) Malignant melanoma, (ii) amelioblastoma (i) Amelioblastoma, (ii) malignant melanoma Please select an option Incorrect. Review oral tumours and choose again. Incorrect. Review oral tumours and choose again. Incorrect. Review oral tumours and choose again. Incorrect. Review oral tumours and choose again. Correct

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What do you recommend to your client? Do nothing. This tumour is large and must have invaded the temporal muscles. Advise an incisional biopsy and computed tomography (CT) scan to determine the extent of the tumour. Excise what you can from the inside of the mouth. Recommend palliative care and send him home on non-steroidal anti-inflammatory drugs (NSAIDs). That irrespective of a biopsy the prognosis is poor and you would have to remove his dog’s jaw. Please select an option Incorrect. You have made a judgement without attempting to evaluate your patient. Understandably your client is not satisfied and goes for a second opinion. Correct Incorrect. That would not benefit your patient and would literally just make a mess. Your client decides to get a second opinion. Incorrect. Your client wants to know if anything further can be done for his dog and therefore seeks a second opinion. Incorrect. You need a better idea of the extent of the tumour and exactly what it is before deciding on options.

Histopathlogy report

Stratified squamous epithelium covering the tissue is ulcerated. The epithelial tissue is proliferative and contiguous in places with a mass present below. The underlying collagen is infiltrated by a solid mass of proliferating squamous epithelial tissue. The epithelial tissue occurs as masses, trabeculae or nests with minimal stromal tissue. The epithelial cells are variable in size; they have large nuclei with prominent nucleoli; mitotic figures are frequent.

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Your client went ahead with the CT scan and biopsy and now wants to know what you found. The biopsy report is available for you to examine but unfortunately the diagnosis is missing so you will have to interpret it for your client. Review the Histopathology report and make your diagnosis. Osteosarcoma Squamous cell carcinoma Malignant melanoma Amelioblastoma Fibrosarcoma Please select an option Incorrect. Making a wrong diagnosis affects the treatment plan and prognosis. Correct. Incorrect. Making a wrong diagnosis affects the treatment plan and prognosis. Incorrect. Making a wrong diagnosis affects the treatment plan and prognosis. Incorrect. Making a wrong diagnosis affects the treatment plan and prognosis.

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You next review the CT scan. What are your findings based on the scan? A this is a large tumour but should be easy to remove as the bone is not affected. There is significant lysis of the mandible so surgery is not an option. The cancer has spread to the nerves so surgery would not be possible. There is significant bony lysis and the tumour is extensive so a hemimandibulectomy would be necessary to debulk this tumour surgically. The tumour has infiltrated the temporal muscles so you don’t know how it could be removed. Please select an option Incorrect. Your client is not convinced and gets a second opinion. Incorrect. Your client is not convinced and gets a second opinion. Incorrect. Your client is not convinced and gets a second opinion. Correct. Incorrect. Your client is not convinced and gets a second opinion.

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