Malignant Melanoma

Malignant melanoma most common in whites; Queensland Australia is a famous high-incidence region. In China incidence is low but patients often present too late due to low awareness; treatment outcomes poor. Age 30-60; rare juvenile melanoma (Spity, 13 cases, 1.5-12y) has lower malignancy and better surgical prognosis. Sex distribution near equal; site varies by sex: trunk = male predominance, extremities = female predominance; facial lentigo-melanoma mainly in elderly women.

Common Symptoms

Pigmented lesion; anterior chamber pigmentation

Causes and Pathogenesis

White hair, blue eyes, pale skin = risk; Blacks/dark skin rarely affected (usually palms/soles). ~50% arise from pre-existing melanocytic nevi. Familial atypical multiple mole melanoma syndrome (autosomal dominant). Sunburn (second-degree/blistering) > chronic exposure. Giant congenital nevi. Histological types: (1) superficial spreading ~70%; (2) nodular ~15%; (3) acral lentiginous ~10%; (4) lentigo maligna ~5%; (5) unclassifiable radial-growth; (6) giant hairy nevus transformation; (7) mucosal (oral/vaginal/anal); (8) unknown primary; (9) blue nevus origin; (10) visceral; (11) pediatric intradermal nevus origin. Growth phases: radial (years, low metastasis, good surgical cure) vs vertical (invasion into dermis/subcutis, node metastasis). Breslow thickness: <=0.75, 0.75-1.5, >1.5mm (further subdivided); thickness directly predicts nodal metastasis/prognosis.

Treatment

Surgery, drug, supportive therapy

Preventive Measures

Avoid sun; sunscreen; early detection/diagnosis/treatment. Prognostic factors: (1) Thickness: Balch 1982, 1442 cases; <=0.75mm 5y survival 89%, >=4mm only 25%. (2) Nodes: 1-3 nodes 41-58%, >=4 nodes 8-26%; nodal status > thickness in impact. (3) Site: trunk worst, head/neck next, extremities best. (4) Surgery: margins 2-3cm (<=0.75mm), 3-4cm (0.75-4mm), 5cm (>4mm); inadequate local excision = 27-57% local recurrence; inadequate node dissection promotes systemic spread. (5) Age/sex: juvenile best; <45y better than older; women > men.

Department to Visit

It is recommended to visit the Surgical Oncology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.