Nodular melanomas: Analysis of the casistic and relationship with thick melanomas and diagnostic delay

Abstract

The present study aimed to: (i) define thick melanomas related to nodular melanomas and other melanoma subgroups; and (ii) establish diagnostic delay in relation to the biological behavior of these melanomas and prevention programs. Cutaneous primary melanomas were studied. Nodular melanoma (NM), lentigo maligna melanoma (LMM) and superficial spreading melanoma (SSM) were selected. A further category named vertical growth melanoma (VGM) was also utilized. Analysis for sex, age, different values of thickness (1-2 mm, > 2 mm; 1-3 mm, > 3 mm; > 4 mm), delay to diagnosis and patterns of detection were performed in all of the different subtypes. Eighty-seven patients with melanomas more than 1 mm of Breslow's thickness out of 506 melanoma were collected. Twenty-six were nodular cases, 39 SSM, five LMM and 17 VGM. Of those patients with NM, 42% had a thickness of more than 1-2 mm, 34% of 2-4 mm, 23% of more than 4 mm; and 54% with 1-3, 46% with more than 3 mm; and 58% with more than 2 mm. Even considering different values of thickness of more than 1 mm, a delay to diagnosis was significantly lower in NM (4.79 months) than in other subgroups. The value of more than 1 mm of Breslow's thickness may be sufficient to consider a melanoma to be thick. The lower diagnostic delay of NM suggests that they represent faster growing lesions probably with a different biological behavior than other melanoma subtypes. VGM should not be confused with NM, having a longer delay and different clinical features compared with the latter. They represent an area of diagnostic carelessness than potentially be improved.

Clinical practice guidelines for the diagnosis and management of melanoma: melanomas that lack classical clinical features

“…Tumour thickness is not necessarily related to diagnostic delay. 2, [20][21][22] While some melanomas grow slowly over a number of years, others will become thick and life-threatening over weeks or months. More rapid growth has been associated with nodular and Melanin pigment is evident at the proximal and lateral nail folds (Hutchinson sign shown by arrows) and there is pigment in the nail bed with haemorrhage.…”

“…Tumour thickness is not necessarily related to diagnostic delay 2 , 20 . ‐ 22 While some melanomas grow slowly over a number of years, others will become thick and life‐ threatening over weeks or months.…”

Nodular melanoma: A distinct clinical entity and the largest contributor to melanoma deaths in Victoria, Australia

“…Unlike ABCD melanomas, NM is more frequently detected by patients as an evolving lesion than picked up by physicians. 6 The more rapid growth rate of NM 7 limits the opportunity for detection during routine skin examinations. It is of critical importance to understand the relative public health impact of these less common presentations to frame and prioritize initiatives to improve early detection by creating awareness.…”

“…Given the strong association of NM with thick melanoma, 6,[11][12][13][14][15] there is room for improvement in early detection. Several studies suggest that early detection of NM may be resistant to the advances that have been seen for SSM.…”