From the Guidelines
Yes, melanoma can be slow growing, with some types developing gradually over months or years rather than rapidly. The growth rate of melanoma varies significantly among different types, with nodular melanoma tends to grow quickly, but other variants like lentigo maligna melanoma typically develop slowly, sometimes taking years to progress 1. Superficial spreading melanoma, the most common type, can also have a prolonged radial growth phase before becoming invasive. This variation in growth rates occurs because melanomas differ in their biological behavior based on genetic mutations and other factors affecting cell division rates. Some key points to consider about melanoma growth rates include:
- Lentigo maligna melanoma is known for its slow growth, often taking years to develop 1
- Superficial spreading melanoma can have a prolonged radial growth phase before becoming invasive 1
- Nodular melanoma tends to grow more quickly than other types 1 The slow-growing nature of some melanomas doesn't make them less dangerous—they still require prompt treatment when detected. Regular skin examinations are essential for early detection, as even slow-growing melanomas can eventually metastasize if left untreated. Treatment typically involves surgical removal with appropriate margins, and depending on the stage, may include sentinel lymph node biopsy, immunotherapy, targeted therapy, or radiation 1.
From the Research
Melanoma Growth Patterns
- Melanoma is known to be a heterogeneous group of tumors with varying growth rates and metastatic potential 2, 3.
- Studies have shown that there is a subgroup of slow-growing melanomas, which may explain the increase in incidence of thin melanoma without a corresponding increase in mortality or incidence of thick melanoma 2.
- Dermoscopy and digital follow-up have been used to monitor and study the natural evolution of melanomas, providing evidence for the existence of slow-growing melanomas 2, 3.
Characteristics of Slow-Growing Melanomas
- Slow-growing melanomas often exhibit minor to moderate changes over time, with less than 2 mm size increase, asymmetrical structural change, and without development of new melanoma-specific criteria 2.
- The most frequent baseline characteristics of slow-growing melanomas include asymmetrical pigmentation, reticular overall pattern, and regression features 2.
- Major changes in slow-growing melanomas are often only visible after a long follow-up period, with a mean follow-up of 33 months 2.
Implications of Slow-Growing Melanomas
- The existence of slow-growing melanomas has implications for the management and treatment of melanoma, highlighting the need for long-term follow-up and monitoring of patients with melanocytic lesions 2, 3.
- The use of dermoscopy and digital follow-up can improve the knowledge about the natural evolution of nevi and melanoma, and help identify patients with slow-growing melanomas 2, 3.