Superficial Spreading Melanoma
The most common type of melanoma characterized by horizontal growth pattern before vertical invasion.
Full Definition
Superficial spreading melanoma (SSM) represents approximately 60-70% of all melanomas and typically exhibits a prolonged horizontal growth phase before developing vertical invasion. This subtype commonly arises in sun-exposed areas and may develop from pre-existing melanocytic nevi. Clinically, SSM often presents as an asymmetric, irregularly bordered lesion with color variation and diameter greater than 6mm. The horizontal growth phase may persist for months to years before the development of nodular components, making early detection and surgical excision critical for optimal outcomes.
Usage
Usage note: May be abbreviated as SSM in clinical contexts, but spell out in formal reports.
In Context
- "Histopathology confirmed superficial spreading melanoma with a Breslow thickness of 0.8 mm." — Pathology report
- "The patient presented with a superficial spreading melanoma exhibiting classic ABCDE criteria." — Clinical assessment