Regression 2/3/18. Histologically regression is characterized: melanosis fibrosis combination of both. Distribution: partial or focal!

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1 Regression Margaret Oliviero MSN, ARNP Harold S. Rabinovitz MD Histologically regression is characterized: melanosis fibrosis combination of both Distribution: partial or focal! Dermatoscopic terminology of regression in the literature ² White scar-like areas ² Depigmented areas ² Gray-blue areas ² Gray-blue veil ² Blue-whitish veil ² Whitish Veil ² Milky way ² Blue areas ² Blue hue ² Pepper-like structures ² Regression structures Zalaudek I, Argenziano G, Ferrara G et al. Clinically equivocal melanocytic skin lesions with features of regression: a dermoscopic pathological study. Br J Dermatol 2004; 150:

2 A blue white veil and regression structures have different histologic correlates! Am J Dermatopathol Oct;23(5): Diagnostic significance of the blue hue in dermoscopy of melanocytic lesions: a dermoscopic-pathologic study. Massi D, De Giorgi V, Carli P, Santucci M. 2

3 Regression structures are present in benign and malignant melanocytic and non-melanocytic neoplasms of the skin Dematologic Surgery Oct,2006 Features of Regression in Dermoscopic Diagnosis: A confounding factor? Two clinical dermoscopic pathologic case studies Neoplasms with regression structures ² Melanoma ² Nevus ² LPLK ² Basal cell carcinoma ² Pigmented actinic keratosis ² Pigmented SCC in situ Basal cell carcinoma Gray dots/granules Melanophages and fibrosis 3

4 Neoplasms with regression structures ² Melanoma ² Nevus ² LPLK ² Basal cell carcinoma ² Pigmented actinic keratosis ² Pigmented SCC in situ Non-Facial Melanomas with gray dots/granules in our practice Out of 228 non-facial melanomas, 145 showed regression: ² 83 melanomas in situ ² 56 thin melanomas Breslow depth </= 0.76mm ² 6 invasive melanomas Breslow depth >/= 0.9mm ² 9 melanomas associated with nevi 4

5 ² Most melanomas with gray dots/granules were melanoma in situ or thin melanomas. ² The majority were diagnosed melanoma on sun-damaged skin. Melanomas on sun-damaged skin have different dermatoscopic patterns Clinical and dermoscopic characteristics of melanomas on nonfacial chronically sun-damaged skin Natalia Jaimes, MD, et al. June 2015 Volume 72, Issue 6, Pages Teaching point Different patterns 5

6 Teaching point Different patterns Angulated line pattern Teaching point Different patterns Tan structureless areas and granularity pattern Teaching point Different patterns Solar lentigo-like pattern 6

7 Granularity (Multiple blue gray dots) ² Small round structures ² < 0.1mm in diameter ² Blue or blue gray ² Variable distribution ² Association with different background color Definition by Ralph Braun 7

8 Part 1 Retrospective study ² 340 biopsy proven lesions randomly chosen from database (170 melanomas matched with 170 Clark nevi) and observed for the presence of multiple blue gray dots Statistically, the diagnosis of melanoma was higher in the presence of: granularity granularity at the periphery irregularly distributed granularity granularity in association with red and white color Part II Prospective study ² 3773 lesions ² 41 lesions showed granulariy (1.08%) If granularity is seen, it is 107 times more likely that the lesion is a melanoma than nevus. 3 However, a nevus with regular granularity that only involves a small portion of the lesion and does not have other dermoscopic criteria for melanoma, does not require surgical removal. Neoplasms with regression structures ² Melanoma ² Nevus ² LPLK ² Basal cell carcinoma ² Pigmented actinic keratosis ² Pigmented SCC in situ 8

9 Nevi with regression structures ² Atypical melanocytic nevus (high grade dysplastic, Clark nevus with unusual features) ² Traumatized nevus ² Halo nevus ² Persistent or recurrent nevus ² Clinically and dermoscopically, atypical melanocytic nevi are often indistinguishable from early melanoma. ² Histologically they are difficult for the pathologist. Nevi with regression structures ² Atypical melanocytic nevus (high grade dysplastic, Clark nevus with unusual features) ² Traumatized nevus ² Halo nevus ² Persistent or recurrent nevus 9

10 ² Traumatized nevi can show focal regression ² Most frequent site: the upper back and areas of friction (in our experience) Nevi with regression structures ² Atypical melanocytic nevus (high grade dysplastic, Clark nevus with unusual features ² Traumatized nevus ² Halo nevus ² Persistent or recurrent nevus A halo nevus can show focal regression with central gray dots/granules surrounded by symmetrical depigmentation 10

11 Nevi with regression structures ² Atypical melanocytic nevus (high grade dysplastic, Clark nevus with unusual features ² Traumatized nevus ² Halo nevus ² Persistent or recurrent nevus ² A persistent or recurrent nevi may show gray dots/granules ² Additional features: radial lines, symmetry, centrifugal growth pattern, and pigmentation confined to the scar Neoplasms with regression structures ² Melanoma ² Nevi ² LPLK ² Basal cell carcinoma ² Pigmented actinic keratosis ² Pigmented SCC in situ 11

12 ² Lichen planus like keratosis is the great masquerader. ² The middle and late stages simulate melanoma on sun-damaged skin Neoplasms with regression structures ² Melanoma ² Nevi ² LPLK ² Basal cell carcinoma ² Pigmented actinic keratosis ² Pigmented SCC in situ ² Gray dots/granules are rarely seen in BCC. ² More common: fine brown dots in focus. ² In addition to regression: look for other BCC features to make a diagnosis 12

13 Neoplasms with regression structures ² Melanoma ² Nevi ² LPLK ² Basal cell carcinoma ² Pigmented actinic keratosis ² Pigmented SCC in situ ² Gray dots/granules can be seen in facial and non-facial pigmented actinic keratosis ² Look for features of a lentigo with shiny white structures particularly rosettes Neoplasms with regression structures ² Melanoma ² Nevi ² LPLK ² Basal cell carcinoma ² Pigmented actinic keratosis ² Pigmented SCC in situ 13

14 ² Gray dots/granules can be seen in facial and non-facial pigmented SCC in situ. ² Features of a lentigo with shiny white lines/structures particularly rosettes ² Additional features of a pigmented SCC in situ: vessels as red dots or coils Thank you for your attention! 14