Embedded Files
Overview & Etiology
Overview & Etiology
• Prevalence: Most frequently diagnosed neoplastic disorders in domestic animals.
• Prevalence: Most frequently diagnosed neoplastic disorders in domestic animals.
• Predisposing Factors:
• Predisposing Factors:
◦ Environmental Exposure: Constant contact with the external environment.
◦ Environmental Exposure: Constant contact with the external environment.
◦ Carcinogens: Chemical carcinogens and ionizing radiation.
◦ Carcinogens: Chemical carcinogens and ionizing radiation.
◦ Biologic Factors: Viruses, hormonal factors, and genetic factors.
◦ Biologic Factors: Viruses, hormonal factors, and genetic factors.
• Tissue Origins:
• Tissue Origins:
◦ Epithelial: Epidermis and adnexa.
◦ Epithelial: Epidermis and adnexa.
◦ Mesenchymal: Fibrous connective tissues, blood vessels, and adipose tissue.
◦ Mesenchymal: Fibrous connective tissues, blood vessels, and adipose tissue.
◦ Neural/Neuroectodermal: Peripheral nerves, Merkel cells, and melanocytes.
◦ Neural/Neuroectodermal: Peripheral nerves, Merkel cells, and melanocytes.
Classification of Lesions
Classification of Lesions
• Hamartoma (Nevus): Localized developmental defect (e.g., sebaceous hamartoma).
• Hamartoma (Nevus): Localized developmental defect (e.g., sebaceous hamartoma).
◦ Congenital: Present at birth, though may reach clinical size later.
◦ Congenital: Present at birth, though may reach clinical size later.
◦ Acquired: Develops in adults; difficult to distinguish from benign neoplasms.
◦ Acquired: Develops in adults; difficult to distinguish from benign neoplasms.
• Benign Neoplasm: Localized, noninfiltrative, encapsulated, and easily excisable.
• Benign Neoplasm: Localized, noninfiltrative, encapsulated, and easily excisable.
• Intermediate Malignancy: Locally infiltrative and difficult to excise, but does not metastasize.
• Intermediate Malignancy: Locally infiltrative and difficult to excise, but does not metastasize.
• Malignant Neoplasm: Infiltrative and has the potential to metastasize.
• Malignant Neoplasm: Infiltrative and has the potential to metastasize.
Clinical Presentation
Clinical Presentation
• Common Forms: Nodular or papular masses.
• Common Forms: Nodular or papular masses.
• Variations:
• Variations:
◦ Alopecic plaques (localized or generalized).
◦ Alopecic plaques (localized or generalized).
◦ Erythematous or pigmented patches/plaques.
◦ Erythematous or pigmented patches/plaques.
◦ Wheals or nonhealing ulcers.
◦ Wheals or nonhealing ulcers.
• Challenge: Variability makes it difficult to distinguish neoplasms from inflammatory diseases.
• Challenge: Variability makes it difficult to distinguish neoplasms from inflammatory diseases.
Diagnosis & Evaluation
Diagnosis & Evaluation
• Cytologic Examination (Fine-needle Aspiration):
• Cytologic Examination (Fine-needle Aspiration):
◦ Purpose: Determine tumor type and plan treatment; can prevent unnecessary surgery for benign masses.
◦ Purpose: Determine tumor type and plan treatment; can prevent unnecessary surgery for benign masses.
◦ Risks: Improper technique can dislodge and "seed" neoplastic cells along the needle track.
◦ Risks: Improper technique can dislodge and "seed" neoplastic cells along the needle track.
• Histologic Examination:
• Histologic Examination:
◦ Generally required for definitive diagnosis.
◦ Generally required for definitive diagnosis.
◦ Immunohistochemical Staining: Used to detect specific cellular markers and determine phenotype.
◦ Immunohistochemical Staining: Used to detect specific cellular markers and determine phenotype.
◦ Margin Assessment: Crucial for predicting local recurrence.
◦ Margin Assessment: Crucial for predicting local recurrence.
• Excisional Biopsy: Direct removal of the mass without prior evaluation based on clinical judgment.
• Excisional Biopsy: Direct removal of the mass without prior evaluation based on clinical judgment.
Treatment Modalities
Treatment Modalities
• Surgery (Primary Option):
• Surgery (Primary Option):
◦ Lumpectomy: For benign lesions.
◦ Lumpectomy: For benign lesions.
◦ Wide Excision: 3 cm surgical margins recommended if malignancy is suspected.
◦ Wide Excision: 3 cm surgical margins recommended if malignancy is suspected.
◦ Debulking: Partial removal to improve the efficacy of radiation or chemotherapy.
◦ Debulking: Partial removal to improve the efficacy of radiation or chemotherapy.
• Radiation Therapy: Used for round cell tumors (e.g., mast cell tumors) or non-resectable infiltrative neoplasms.
• Radiation Therapy: Used for round cell tumors (e.g., mast cell tumors) or non-resectable infiltrative neoplasms.
• Chemotherapy: Can be systemic, intralesional, or applied via electroporation.
• Chemotherapy: Can be systemic, intralesional, or applied via electroporation.
• Other Specialized Therapies:
• Other Specialized Therapies:
◦ Cryosurgery: Most effective for benign, superficial lesions.
◦ Cryosurgery: Most effective for benign, superficial lesions.
◦ Electrochemotherapy: Applied to margins or tumor beds to extend tumor-free intervals.
◦ Electrochemotherapy: Applied to margins or tumor beds to extend tumor-free intervals.
◦ Additional Options: Laser therapy, immunotherapy, gene therapy, and multimodal approaches.
◦ Additional Options: Laser therapy, immunotherapy, gene therapy, and multimodal approaches.
Post-Surgical Management
Post-Surgical Management
• Follow-up: Recommended for at least 2 years to monitor for recurrence.
• Follow-up: Recommended for at least 2 years to monitor for recurrence.
• Close Margins: Animals with infiltrated or close tumor margins require particularly careful management.
• Close Margins: Animals with infiltrated or close tumor margins require particularly careful management.
Page updated
Google Sites
Report abuse