Summary of April JAAD articles

Favorable long-term outcomes in patients with histologically dysplastic nevi that approach a specimen border

Thomas L. Hocker, MD,a Ali Alikhan, MD,a Nneka I. Comfere, MD,a,b and Margot S. Peters, MDa,b

Rochester, Minnesota

See related letters on pages 682 and 683

Background: Patients with multiple clinically dysplastic nevi are at increased risk for development of melanoma. However, the risk of melanoma arising in a histologically dysplastic nevus (HDN) is unknown.

Objective: We sought to determine the rate of melanoma development in patients with HDNs that approached a microscopic border but were not re-excised.

Methods: We performed a retrospective study of patients evaluated in our dermatology department from January 1, 1980, to December 31, 1989, who had a HDN that extended to within 0.2 mm of a microscopic punch, shave, or excision border and was not re-excised.

Results: The average follow-up in our cohort of 115 patients was 17.4 years (range: 0.0-29.9): 82 patients (71.3%) were followed up for longer than 10 years, 78 (67.8%) longer than 15 years, and 73 (63.4%) had more than 20 years of follow-up; 66 of 115 nevi were mildly dysplastic, 42 moderately dysplastic, and 7 had severe dysplasia. No patient developed metastatic melanoma or melanoma at the site of removal of a HDN.

Limitations: This was a retrospective study performed at 1 large academic medical center.

Conclusion: During a long-term follow-up period, no patient developed melanoma at the site of an incompletely or narrowly removed HDN, providing evidence that routine re-excision of mildly or moderately dysplastic nevi may not be necessary. ( J Am Acad Dermatol 2013;68:545-51.)



Negative pigment network: An additional dermoscopic feature for the diagnosis of melanoma

Maria A. Pizzichetta, MD,a Renato Talamini, ScD,a Ash A. Marghoob, MD,b H. Peter Soyer, MD,c Giuseppe Argenziano, MD,d Riccardo Bono, MD,e M. Teresa Corradin, MD,f Vincenzo De Giorgi, MD,g Marian A. Gonzalez, MD,h Isabel Kolm, MD,I Andrew W. Kopf, MD,j Joseph Malvehy, MD,k Niccolo Nami, MD,  Margaret Oliviero, MD,I Giovanni Pellacani, MD,m Susana Puig, MD,k Harold Rabinovitz, MD,I Pietro Rubegni, MD,l Stefania Seidenari, MD,m Ignazio Stanganelli, MD,n Andrea Veronesi, MD,a Iris Zalaudek, MD,o Pierfrancesco Zampieri, MD,h and Scott W. Menzies, MB, BS, PhDp Aviano, Reggio Emilia, Rome, Pordenone, Florence, Merano, Siena, Modena, and Meldola, Italy; New  York, New York; Miami, Florida; Barcelona, Spain; Graz, Austria; and Brisbane and Sydney, Australia

Background: The negative pigment network (NPN) is seen as a negative of the pigmented network and it is purported to be a melanoma-specific structure.

Objectives: We sought to assess the frequency, sensitivity, specificity, and odds ratios (ORs) of NPN between melanoma cases and a group of control lesions.

Methods: Digitalized images of skin lesions from 679 patients with histopathological diagnosis of dermatofibroma (115), melanocytic nevus (220), Spitz nevus (139), and melanoma (205) were retrospectively collected and blindly evaluated to assess the presence/absence of NPN.

Results: The frequency of occurrence of NPN was higher in the melanoma group (34.6%) than in Spitz nevus (28.8%),melanocytic nevus (18.2%), and dermatofibroma (11.3%) groups. An OR of 1.8 emerged for the diagnosis of melanoma in the presence of NPN as compared with nonmelanoma diagnosis. Conversely, for melanocytic nevi and dermatofibromas the OR was very low (0.5 and 0.3, respectively). For Spitz nevi the OR of 1.1 was not statistically significant. When comparing melanoma with dermatofibroma, melanocytic nevus, and Spitz nevus, we observed a significantly higher frequency of multicomponent pattern (68.1%), asymmetric pigmentation (92.9%), irregularly distributed NPN (87.3%), and peripheral location of NPN (66.2%) in melanomas.

Limitations: Further studies can provide the precise dermoscopic-histopathologic correlation of NPN in melanoma and other lesions.

Conclusions: The overall morphologic pattern of NPN, such as the irregular distribution and the peripheral location of NPN, along with the multicomponent pattern and the asymmetric  pigmentation could be used as additional features in distinguishing melanoma from Spitz nevus and other benign lesions.

( J Am Acad Dermatol 2013;68:552-9.)



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

Victoria Mar, MBBS, FACD,a,b,c Hugh Roberts, MBBS, FACD,a Rory Wolfe, BSc, PhD,a,b Dallas R. English, BSc, PhD,d,e and John W. Kelly, MBBS, FACD, MDa Melbourne, Australia

Background: There is a growing body of evidence that nodular melanoma (NM), because of its association with increased growth rate and thickness at diagnosis, accounts for a substantial proportion of melanoma deaths.

Objective: We sought to assess the contribution of NM to melanoma deaths in comparison with other tumor subtypes.

Methods: Four cohorts were established comprising 5775 cases of invasive primary cutaneous melanoma reported to the Victorian Cancer Registry during 1989, 1994, 1999, and 2004. Original pathology reports were reviewed. Age-standardized melanoma incidence rates were compared from 1989 to 2004 with annual percentage change using Poisson regression.

Results: The incidence of thick tumors ([4 mm) increased by 3.8% (95% confidence interval 1.4 to 6.2) and 2.5% (95% confidence interval 0.5 to 5.5) per year for male and female patients, respectively. The median thickness of NM at diagnosis was 2.6 mm compared with 0.6 mm for superficial spreading melanoma. A third of patients who died from melanoma during the follow-up period had thick tumors ([4 mm), most of which were nodular subtype (61%). NM accounted for 14% of invasive melanomas, but was responsible for 43% of melanoma deaths in a total of 57,461 person-years of follow-up. By comparison, superficial spreading melanoma contributed 56% of invasive melanoma but only 30% of deaths.

Limitations: Pathology review was limited to reports only. Mortality information relied mostly on death certificate information.

Conclusion: The incidence of thick melanomas continues to increase. Nodular melanoma is clinically distinct and the predominant contributor to melanoma-related deaths, representing a public health challenge in reducing skin cancer mortality. ( J Am Acad Dermatol 2013;68:568-75.)

Key words: histologic type; melanoma; melanoma deaths; melanoma incidence; melanoma survival; nodular melanoma; tumor subtype.



Pigmented solar (actinic) keratosis: An underrecognized collision lesion

Hye Jin Chung, MD,a Kelly L. McGuigan, MD,b Katie L. Osley, MD,a Kate Zendell, MD,a and Jason B. Lee, MDa Philadelphia, Pennsylvania, and Annapolis, Maryland

Background: The lack of well-established diagnostic criteria for pigmented solar (actinic) keratosis (PSK) along with its poorly understood etiopathogenesis has contributed to underrecognition.

Objective: The clinical, dermatoscopic, and histopathologic features of PSK and the cause of the pigmentation are elucidated.

Methods: In all, 167 histologic specimens, 22 clinical images, and 17 dermatoscopic images of PSK were reviewed. In 38 cases, Melan-A stained sections were available for analysis.

Results: The majority of the lesions were located on the head and neck (84%). A separate pigmented lesion was adjacent to or admixed within PSK in 138 (83%) of the cases indicating that PSK represents a collision between a nonpigmented solar keratosis and a pigmented lesion. Solar lentigo (72%) was the most commonly associated pigmented lesion followed by seborrheic keratosis and melanoma. PSK was suspected clinically in 17% of the cases. There were no significant differences in the quality and quantity of the melanocytes between pigmented and nonpigmented solar keratosis.

Limitations: This was a single-center retrospective study. The sample sizes were small for the clinical and dermatoscopic images and Melan-A stains.

Conclusion: In the majority of the cases, a collision between a nonpigmented solar keratosis and a separate coexistent pigmented lesion, primarily a solar lentigo, accounts for the pigmentation in PSK rather than from any fundamental changes in the quantity or quality of the melanocytes. The collision phenomenon accounts for the spectrum of the clinical and dermatoscopic features observed in PSK and its underrecognition. ( J Am Acad Dermatol 2013;68:647-53.)

Key words: collision tumor; Melan-A; melanoma; pig