Malignant melanoma in dogs: diagnosis and treatment

Melanoma is a cancer that happen as a result of the unregulated proliferation in melanocytes in canines skin, mouth, eye, and toenails. This PPT illustrates types of canine melanoma, diagnosis of tumor,and treatment methods.

1. Malignant Melanoma in Dogs Prepared by: Dr. Amira Heniedy

2. Malignant Melanoma Melanoma is a cancer that happen as a result of the unregulated proliferation in melanocytes in canines skin, mouth, eye, and toenails. Epidemiology of Malignant Melanoma incidence and prevalence Melanocytomas (benign melanoma)accounts for 30% of all melanin producing tumors, while malignant melanoma accounts for 70%. Melanoma are most frequently identifies in oral(62%), dermal (3%), nailbed (6%), and ocular (5%).

3. Types of Malignant melanoma in dogs Oral Melanoma Nailed Melanoma Most of oral melanomas are dark in colour in mouth Affected digits have deformed nails,and growth of a mass from nailbed, or paronychia Dermal melanoma Ocular Melanoma Most dermal melanomas are dark and raised masses. Amelanotic melanomas appears as a pinkish color A growing dark spot in the Iris and a change in the shape of the pupil are the most common signs of ocular melanoma

4. Diagnosis 1- Cytology Melanoma cells may be mimic round cells, epithloid, or spindle-shaped neoplasm. Nucleus: oval , prominant, large , pale, and dark-staining nucleoli. Melanin pigment granules: dust-like , needle shaped , or granular ( small amount of intracellular gray/black/green pigment may be seen) Normal melanocytes Spindle-shaped cell melamoma

5. 2- Biopsy Punch biopsy Tru-cut needle biopsy Punch biopsy is more favorable for accurate diagnosis specially in oral melanomas. Punch biopsy offer large incesion biospies Tru-cut needle biopsy can be used, but several samples from different areas should be performed to avoid limiting diagnosis between sarcoma and malignant tumor Pathological Tests

6. 3- Biomarkers The common markers used to identify canine melanomas are Melan-A, PNL2, and tyrosinase related protein 1 and 2 (TRP-1 and TRP-2) The frequency of CSPG4 expression was similar to that of other melanoma antigens used as diagnostic markers for canine malignant melanoma. Canine melanoma biomarkers Diagnostic marker 02 01 Prognostic marker

7. Diagnostic markers Diagnostic markers are biological parameters that aid the diagnosis of tumor. These biomarkers may be proteins or other substances that are made at higher amounts by cancer dells than normal cells. Prognostic markers Prognostic markers are biological characteristics that are objectively measured and evaluated to predict the course of tumor or a response to a therapeutic intervention.

8. Diagnostic markers in canine malegnant melanoma No Marker Method of identification Application 1 Melan-A Immunohistochemistry Immunocytochemistry Immunofluoresence RT-qPCR differeatiation between healthy tissue and melanocytic tissue Confirm melanoma orgin 2 PNL2 3 TRP-1 & TRP-2 4 SOX-10 5 TYR,CD34&CALD1 6 MITF

9. Prognostic markers in canine malegnany melanoma No Marker Method of identification Application 1 Survivin Immunohistochemistry Immunocytochemistry Immunofluoresence RT-qPCR qPCR Marking of proliferating and resistant to apoptosis tumor cells 2 H2AFZ 3 RACK1 4 CD20+ 5 KIT,c-Kit 6 S100A4 7 E-cadherin 8 FoxP3,IDO,and CTLA-4 9 Ki67 10 Somatic focal amplification of chromosome 30(CFA 30) 11 PCNA and Connexins

10. Treatment of Canine melanoma Surgical treatment Complete removal of affected parts of tumor and regional lymph nodes to avoid metastases. Radiotherapy Medical therapy Adjuvant immunotherapy Atherapeutic vaccine containing xenogenetic plasmid DNA with an insert encoding human (ex, ONCEPT ®) Adjuvant chemotherapy (ex,Carboplatin, Melphalan,Cisplatin)

11. Thank you