Kurt S. Stenn

Telogen skin contains an inhibitor of hair growth.

We have investigated whether C 57 Br‐6 mouse skin with all its follicles in the telogen stage of the hair cycle contains a hair‐growth inhibitory activity, as opposed to skin with anagen follicles. Crude aqueous extracts of whole telogen mouse skin (TE), anagen skin (AE) or vehicle alone (V) were injected intraperitoneally into mice in which anagen had previously been induced by plucking of telogen hair follicles. Injection of TE, but not AE or V, significantly retarded the development of anagen follicles, as measured by macroscopic and quantitative microscopic hair growth parameters (skin pigmentation and thickness, appearance of trichohyaline granules) and the incorporation of tritiated thymidine into mouse skin from animals previously treated with either TE or V (skin organ culture). This inhibitory activity seemed to be localized to the epidermis and was also present in rat epidermis. We suggest that this apparently non‐speciesspecific inhibitor present in telogen skin may play a role in regulating the hair cycle in rodents.

Alopecia areata investigational assessment guidelines

From Duke University Medical Center, Durhama; University of Minnesota, Minneapolisb; Pontefract General Infirmaryc; University of California at San Franciscod; Northwest Cutaneous Research Specialists, Portlande; The University of British Columbia, Vancouverf; and Johnson & Johnson, Skin Biology Research Center, Skillman.g Reprint requests: Elise A. Olsen, MD, Professor of Medicine, Duke University Medical Center, Box 3294, Durham, NC 27710. J Am Acad Dermatol 1999;40:242-6. *Developed from the Alopecia Areata Consensus meeting sponsored by the National Alopecia Areata Foundation at the First Tricontinental Meeting of the Hair Research Societies, Brussels, Belgium, Oct 8, 1995. Participants are listed at the end of the guidelines. Copyright

Malignant blue nevus: Case report and literature review

A well-documented case of malignant blue nevus is presented, along with an in-depth review of the literature. Malignant blue nevus is a rare form of malignant melanoma. A cellular blue nevus is the precursor lesion. The scalp is the most common site. The tumor often presents clinically as a progressively enlarging or multinodular blue-black lesion. The histologic pattern is fascicular dense collections of pigmented, pleomorphic spindle cells. Because of marked regional histologic variation within a malignant blue nevus, however, sampling error can cause delay in recognition of malignancy. A high clinical index of suspicion and appropriate biopsy technique are necessary to reach an early diagnosis. The most common site of metastasis of a malignant blue nevus is the lymph node. The phenomenon of benign lymph node nevus cell metastasis, which may occur with benign blue nevi, must be differentiated from a true malignant metastasis of a malignant blue nevus.

Mycosis fungoides: Clinicopathologic relationships, survival, and therapy in 59 patients with observations on occupation as a new prognostic factor

Clinicopathologic relationships, survival, and therapy were reviewed in 59 patients with mycosis fungoides (MF). An analysis of patient survival disclosed that stage of disease was a significant prognostic variable only if both cutaneous and visceral manifestations were considered in the staging design. The classical three‐stage format, based solely on findings of eczema (I), plaques (II), or skin tumors (III), was not a significant factor in predicting survival. However, the inclusion of lymphadenopathy (IV) and organomegaly (V) or circulating Sézary cells (VI) in an expanded model revealed a significant decline in the probability of survival with increasing stage of disease. Regarding cases where the original histopathologic material was available for review, there was no association between the histologic stage of the specimen and the morphology of skin lesions. These data militate against the use of a staging scheme based on histologic criteria. Among 30 different types of treatment employed during the course of this study, highdose electron beam was superior to all other physical and chemotherapeutic modalities. In a case‐control study considering occupational factors, patients with MF who were employed in manufacturing or construction industries were at significantly increased risk (relative risk = 4.3). Patient survival was reduced considerably for those with industrial backgrounds, suggesting that this subgroup was inclined to have severe disease. The concept that occupational factors may be implicated in the etiology of mycosis fungoides provides a new dimension to previous pathogenic hypotheses that needs further evaluation.

Nevomelanocytic proliferations in association with cutaneous malignant melanoma: A multivariate analysis

Two hundred forty-eight cases of melanoma accessioned from 1984 through 1985 were independently reviewed by a panel of dermatopathologists for the presence of nevomelanocytic proliferations in histologic contiguity with melanoma. One hundred ninety-seven cases remained in the sample for analysis after cases with insufficient histologic material and those diagnosed without primary melanoma were excluded. We found that 32.5% of melanomas (95% confidence interval, 25.9% to 39.7%) were associated with a benign or dysplastic nevus in histologic contiguity. Melanoma type and anatomic location were significant predictors of contiguous nevomelanocytic proliferations when considered alone. After adjustment, however, only melanoma type significantly predicted the presence of a contiguous histologic evidence of a precursor nevus than was nodular melanoma (odds ratio, 11.1; 95% confidence interval, 1.4 to 86.6) and were almost 22 times more likely to be associated with a nevus than was lentigo maligna melanoma (odds ratio, 21.45; 95% confidence interval, 2.8 to 162.4). This evidence supports the concept of the heterogeneity of melanoma histogenesis.

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.

Patterns of congenital nevocellular nevi: A histologic study of thirty-eight cases

A series of thirty-eight cases of congenital nevocellular nevi were excised and studied histologically. Depending on the extent of nevoid cell dermal infiltration, four histologic patterns were observed: diffuse or patchy infiltration of the upper dermis alone, or diffuse or patchy infiltration of the upper and deep dermis with nevoid cells in or below the lower one third of the reticular dermis. Nevoid cells extended into the deepest reticular dermis in only 37% of these patients. There was no significant correlation between the four histologic patterns and age, sex, location, or lesion size. Two cases recurred after surgery but none underwent malignant change. The patients who developed recurrent nevi in the surgical site postexcision manifested the diffuse upper and deep dermal pattern of nevoid cell infiltration. We interpret this observation as due to incomplete excision of the primary lesion, reflecting the difficulty of removing congenital nevi with this histologic pattern. We conclude from this study that: (1) congenital nevocellular nevi show at least four typical histologic patterns; (2) the nevoid cells of congenital nevi do not necessarily extend into the deep dermis; and (3) of the four histologic patterns seen in congenital nevi, that one showing diffuse and deep placement of nevoid cells on biopsy requires more aggressive excision to prevent recurrence.

An analysis of interobserver recognition of the histopathologic features of dysplastic nevi from a mixed group of nevomelanocytic lesions

BACKGROUND The diagnostic criteria for the histopathologic recognition of the dysplastic nevus are defined, but difficult to apply in practice. However, the use of skin biopsy is on the increase to search for this nevus because of a possible role in melanomagenesis. OBJECTIVE The aim was to determine the degree of observer reproducibility in the detection of histologic nevomelanocytic dysplasia as measured across multiple observers and to test whether each observer was precise over a wide sample population. A second aim was to gain some measure of the threshold a person has for such lesions. METHODS Histologic specimens from 50 coded nevomelanocytic tumors, which included a group of dysplastic nevi, were independently read by five observers in a blinded fashion. At study completion, the same 50 cases were read again by a melanoma reference pathologist and results analyzed by Cohens kappa to assess agreement and interobserver variation. RESULTS Corrected rates of agreement for dysplastic nevi ranged from 0.32 to 0.71. CONCLUSION Continued study and experience are required for precision and reproducibility in the histologic recognition of dysplastic nevi.

What is the biological basis of pattern formation of skin lesions

Abstract:  Pattern recognition is at the heart of clinical dermatology and dermatopathology. Yet, while every practitioner of the art of dermatological diagnosis recognizes the supreme value of diagnostic cues provided by defined patterns of ‘efflorescences’, few contemplate on the biological basis of pattern formation in and of skin lesions. Vice versa, developmental and theoretical biologists, who would be best prepared to study skin lesion patterns, are lamentably slow to discover this field as a uniquely instructive testing ground for probing theoretical concepts on pattern generation in the human system. As a result, we have at best scraped the surface of understanding the biological basis of pattern formation of skin lesions, and widely open questions dominate over definitive answer. As a symmetry‐breaking force, pattern formation represents one of the most fundamental principles that nature enlists for system organization. Thus, the peculiar and often characteristic arrangements that skin lesions display provide a unique opportunity to reflect upon – and to experimentally dissect – the powerful organizing principles at the crossroads of developmental, skin and theoretical biology, genetics, and clinical dermatology that underlie these – increasingly less enigmatic – phenomena. The current ‘Controversies’ feature offers a range of different perspectives on how pattern formation of skin lesions can be approached. With this, we hope to encourage more systematic interdisciplinary research efforts geared at unraveling the many unsolved, yet utterly fascinating mysteries of dermatological pattern formation. In short: never a dull pattern!

Lipids to the Top of Hair Biology

Little attention has been given to the impact of lipid metabolism on hair follicle biology and pathology. Three recent papers (one in the current issue) describe a major effect of altered lipid metabolism on hair growth. A direct link was made to at least one form of cicatricial alopecia, but the role lipids play in other follicular pathologies, such as the acneiform conditions, are inadequately explored and must be tested.