Jean L. Bolognia

Lines of Blaschko.

The lines of Blaschko represent a pattern followed by many skin disorders. We review the clinical and histologic features of X-linked, congenital/nevoid, and acquired skin diseases that follow these lines. We also include cutaneous disorders that have a linear distribution but do not follow Blaschkos lines. Finally, we differentiate Blaschkos lines from other patterns on the skin such as dermatomes and Langers lines.

AAD/ACMS/ASDSA/ASMS 2012 appropriate use criteria for Mohs micrographic surgery: A report of the American Academy of Dermatology, American College of Mohs Surgery, American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery

The appropriate use criteria process synthesizes evidence-based medicine, clinical practice experience, and expert judgment. The American Academy of Dermatology in collaboration with the American College of Mohs Surgery, the American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery has developed appropriate use criteria for 270 scenarios for which Mohs micrographic surgery (MMS) is frequently considered based on tumor and patient characteristics. This document reflects the rating of appropriateness of MMS for each of these clinical scenarios by a ratings panel in a process based on the appropriateness method developed by the RAND Corp (Santa Monica, CA)/University of California-Los Angeles (RAND/UCLA). At the conclusion of the rating process, consensus was reached for all 270 (100%) scenarios by the Ratings Panel, with 200 (74.07%) deemed as appropriate, 24 (8.89%) as uncertain, and 46 (17.04%) as inappropriate. For the 69 basal cell carcinoma scenarios, 53 were deemed appropriate, 6 uncertain, and 10 inappropriate. For the 143 squamous cell carcinoma scenarios, 102 were deemed appropriate, 7 uncertain, and 34 inappropriate. For the 12 lentigo maligna and melanoma in situ scenarios, 10 were deemed appropriate, 2 uncertain, and 0 inappropriate. For the 46 rare cutaneous malignancies scenarios, 35 were deemed appropriate, 9 uncertain, and 2 inappropriate. These appropriate use criteria have the potential to impact health care delivery, reimbursement policy, and physician decision making on patient selection for MMS, and aim to optimize the use of MMS for scenarios in which the expected clinical benefit is anticipated to be the greatest. In addition, recognition of those scenarios rated as uncertain facilitates an understanding of areas that would benefit from further research. Each clinical scenario identified in this document is crafted for the average patient and not the exception. Thus, the ultimate decision regarding the appropriateness of MMS should be determined by the expertise and clinical experience of the physician.

Biology of hypopigmentation

A review of the basics of pigment cell biology is followed by a discussion of the characteristics of several disorders of hypopigmentation. By determining such features as inheritance pattern, time of onset (congenital, childhood, adulthood), natural history (stable vs progressive), type of pigment loss (diffuse or circumscribed), distribution of lesions (generalized vs localized), degree of pigment loss (incomplete or complete), number of melanocytes, if any, in biopsy specimens of affected areas, type of melanocytic dysfunction, and associated inflammation or infection, one can classify the disorders of hypopigmentation. The proposed pathophysiology for each disorder of hypomelanosis is presented.

Follow-up recommendations for patients with American Joint Committee on Cancer Stages I-III malignant melanoma.

Guidelines for follow‐up of melanoma patients are not established. In 1987, a follow‐up protocol was instituted at the Yale Melanoma Unit to improve upon the detection of disease recurrence in patients with American Joint Committee on Cancer Stage I–III cutaneous melanoma. The follow‐up protocol consists of a patient education program and a surveillance schedule based on stage of disease.

UVB-induced melanogenesis may be mediated through the MSH-receptor system.

Ultraviolet B radiation (UVB) elicits an increase in melanin production in mammalian skin. The mechanisms regulating this process are not understood, although it is well documented that there is an increase in the number of melanin-producing melanocytes. The melanotropins (MSH) are a family of peptides that increase the melanin content of melanocytes through an interaction with high affinity receptors. We have obtained evidence that the effects of UVB on melanogenesis may be mediated through an increase in MSH receptor activity on melanocytes. First, exposure of Cloudman S91 mouse melanoma cells to UVB resulted in increased binding of 125I-MSH to cells within 24 h. In five separate experiments, UVB-irradiated cultures displayed 2-10-fold increases in MSH binding capacity over that of unirradiated control cultures (optimum doses 10-20 mJ/cm2). Second, UVB and MSH potentiated one another in promoting cutaneous melanogenesis in both mice and guinea pigs. In the areas of guinea pig skin that received both UVB and MSH, there was a fivefold increase in active melanocytes/mm2 over the sum of active melanocytes/mm2 in areas receiving either MSH or UVB separately. Our results suggest that UVB light causes an increase in MSH receptor activity on cutaneous melanocytes, thus increasing cellular responsiveness to MSH. Implicit in this mechanism is a transduction of radiant energy into chemical energy during the process of UVB-induced melanogenesis.

Melanoma × macrophage hybrids with enhanced metastatic potential

Studies were conducted on the hypothesis that melanoma metastasis might be initiated through the gener-ation of hybrids comprised of cells of the primary tumor and tumor-infiltrating leukocytes. Fusion hybrids were generated in vitro between weakly metastatic Cloudman S91 mouse melanoma cells and normal mouse or human macrophages. Hybrids were implanted s.c. in the tail and mice were monitored for metastases. Controls included parental S91 cells, autologous S91 × S91 hybrids, and B16F10 melanoma cells. Of 35 hybrids tested, most were more aggressive than the parental melanoma cells, producing metastases sooner and in more mice. A striking characteristic was heterogeneity amongst hybrids, with some lines producing no metastases and others producing metastases in up to 80% of mice. With few exceptions, hybrids with the highest metastatic potential also had the highest basal melanin content whereas those with the lowest metastatic potential were basally amelanotic, as were t he parental melanoma cells. A spontaneous in vivo supermelanotic hybrid between an S91 tumor cell and DBA/2J host cell was one of the most metastatic lines. Hybrids with the highest metastatic potential also exhibited markedly higher chemotaxis to fibroblast-conditioned media. Histologically, the metastatic hybrids demonstrated vascular invasion and spread to distant organs similar to that of metastatic melanomas in mice and humans. Thus previous findings of enhanced metastasis in leukocyte × lymphoma hybrids can now be extended to include leukocyte × melanoma hybrids. Whether such hybridization is a natural cause of metastasis in vivo remains to be determined; however the fusion hybrids with genetically-matched parents described herein so closely resembled naturally- occurring metastatic melanoma cells that they could serve as useful new models for studies of this complex and deadly phenomenon.

Bazex Syndrome (Acrokeratosis paraneoplastica) An analytic review

Bazex syndrome (acrokeratosis paraneoplastica) is characterized by a psoriasiform eruption that favors acral sites and has been associated with an underlying malignancy in all reported cases. Of the 93 patients in this series, 89 were male with a mean age of 60 +/- 8.5 years. Squamous cell carcinomas of the head and neck and squamous cell tumors of unknown primary with cervical lymph node metastases were the most commonly associated neoplasms, suggesting that the factor(s) responsible for the development of the syndrome are relatively specific for tumors of the upper aerodigestive tract. The cutaneous lesions were erythematous to violaceous in color and had associated scale; the most frequently observed sites of involvement were the ears, nose, hands, and feet, including the nails. In 63% of the cases, the cutaneous lesions preceded the initial symptoms or diagnosis of the tumor by an average of 11 months (range, 1-72) and, in general, the eruption was resistant to a variety of topical treatments. Occasionally, a reappearance of the papulosquamous lesions signaled the recurrence of the tumor (6 cases) or the appearance of skin lesions coincided with the development of metastatic disease (3 cases). In 91% (64/70) of the patients, the skin eruption either improved significantly following treatment of the underlying malignancy or did not improve in the setting of persistent tumor. However, even when all of the skin lesions cleared, the nail dystrophy often persisted. Fifteen of the patients developed vesicles, bullae, and crusts in addition to papulosquamous lesions. Possible explanations include the formation of an epidermal-dermal split via a bullous lichen planus-like mechanism, or the coexistence of two diseases; i.e., acrokeratosis paraneoplastica plus either porphyria cutanea tarda, bullous pemphigoid, or epidermolysis bullosa acquisita. One possible explanation for the development of the characteristic cutaneous eruption is an immune reaction, humoral or cellular, directed against a common antigen present on the tumor and the normal skin. Alternatively, tumor production of a keratinocyte growth factor such as TGF-alpha may be involved in the induction of the psoriasiform skin lesions.

UV Light and MSH Receptors

ABSTRACT: Ultraviolet B (UVB) radiation in the skin induces pigmentation that protects cells from further UVB damage and reduces photocarcinogenesis. Although the mechanisms are not well understood, our laboratory has shown that UVB radiation causes increased MSH receptor activity by redistributing MSH receptors from internal pools to the external surface, with a resultant increase in cellular responsiveness to MSH. By this means, UVB and MSH act synergistically to increase melanin content in the skin of mice and guinea pigs. In humans, MSH causes increased skin pigmentation, predominantly in sun‐exposed areas. We have shown recently that UVB irradiation and exposure to MSH or to dbcAMP, stimulates production of mRNAs for both αMSH receptors and POMC in human melanocytes and keratinocytes. This indicates that at least one action of UVB on the pigmentary system is mediated through increased MSH receptor production, as well as through the production of the signal peptides, MSH and ACTH, that can further activate MSH receptors. The results add support to the hypothesis that the effects of UVB on cutaneous melanogenesis are mediated through a series of coordinated events in which MSH receptors and POMC‐derived peptides play a central role.

Ectodermal dysplasias associated with clefting: Significance of scalp dermatitis

Several clinical syndromes are characterized by ectodermal dysplasia (ED) in association with clefting of the lip and/or palate. The three most commonly recognized entities are (1) the EEC syndrome (ectodermal dysplasia, ectrodactyly, cleft lip/palate); (2) the Rapp-Hodgkin syndrome with ectodermal dysplasia, cleft lip/palate, and mid facial hypoplasia; and (3) the Hay-Wells or AEC syndrome (ankyloblepharon, ectodermal defects, cleft lip/palate). The clinical characteristics of these entities as well as several less common syndromes are reviewed and summarized. The presence of scalp dermatitis in patients with the AEC syndrome and less often the Rapp-Hodgkin syndrome is emphasized.

Complete follow-up and evaluation of a skin cancer screening in Connecticut

On May 21, 1988, 251 persons were screened for skin cancer in New Haven, Connecticut. A total body skin examination was performed on 98% of the participants. On the basis of follow-up of 93% of persons with positive screens for basal cell carcinoma, squamous cell carcinoma, or Bowens disease, positive predictive values were 43% for basal cell carcinoma, 14% for squamous cell carcinoma, and 50% for Bowens disease. In the group with atypical nevi, a person with two or more clinically atypical nevi was 16 times more likely to have histologic confirmation than a person with a single clinically atypical nevus (p = 0.003). Eighty persons were screened by both a dermatologist and a dermatology nurse; the crude agreement rate for actinic keratoses was 0.62; for atypical nevi, 0.53; and for BCC, 0.88. Both nurses and physicians overdiagnosed in the screening setting, the nurses more so than the physicians. Of the 128 persons screened who were advised to seek medical follow-up, 16 did not do so despite several reminders; their reasons are discussed.