Cutaneous Melanoma The BRAF V600 mutation is a frequent somatic/acquired driver mutation in cutaneous melanoma. Cyclin-dependent kinase inhibitor 2A (CDKN2A) is the most frequently mutated high-risk gene associated with familial cutaneous melanoma. Staging: Any N+ disease is Stage IIIA and up Memorize staging: Stage Thickness Ulceration T1a < 0.8 mm No T1b < 0.8 mm Yes T1b 0.8–1 mm with or without T2a 1–2 mm No T2b 1–2 mm Yes T3a 2–4 mm No T3b 2–4 mm Yes T4a > 4 mm No T4b > 4

Risk factors: HPV infection (16, 18, 33, 35) Smoking Alcohol use (synergistic with smoking) Betelnut chewing Genetic factors such as Fanconi Anemia (avoid alkylating agents and radiation due to increased toxicity in these patients) Sites of tumor: Oral Cavity: mucosal lip, Buccal mucosa, anterior tongue, hard palate Oropharyngeal Cancer: upper throat, tonsil, base of tongue, soft palate, pharyngeal wall Hypopharyngeal Cancer (lower throat) Laryngeal Cancer Treatment: Principl

Work up for staging: CT CAP with IV and oral contrast Endoscopic Ultrasound Bronchoscopy for tumors at/above the carina to rule out fistula Upper GI endoscopy/biopsy Consider staging laparoscopy: Best test to assess peritoneal metastases (mostly seen in signet ring histology). At least 15 LNs need to be removed during surgery Staging: T1a: Tumor invades the lamina propria or muscularis mucosae T1b: Tumor invades the submucosa T2: Tumor invades the muscularis propria T3: Tumor

This post is a summary of work-up, staging and treatment of perianal and anal squamous cell carcinoma.