Hideko Kamino

Dermatofibroma extending into the subcutaneous tissue. Differential diagnosis from dermatofibrosarcoma protuberans.

When dermatofibromas are composed predominantly of fibroblasts and extend into the subcutaneous tissue, it may be difficult to distinguish them from dermatofibrosarcoma protuberans. Because the patterns of extension of dermatofibroma have not been well characterized, we studied 185 cases of the fibrous variant of dermatofibroma with extension into the subcutaneous tissue and 40 cases of dermatofibrosarcoma protuberans. Dermatofibromas had two main patterns of extension into subcutaneous tissue. One pattern, seen in 133 of 185 cases (72%), consisted of irregular extension into the subcutaneous tissue in a vertical or radial fashion, predominantly along the septa, which appeared wedge-shaped. The other pattern, seen in 52 of 185 cases (28%), showed a smooth and well-demarcated deep margin that bulged into the subcutaneous tissue. Dermatofibrosarcoma protuberans also had two main patterns of extension into the subcutaneous tissue. In one pattern, seen in 12 of 40 cases (30%), slender spindle-shaped cells extended along septa and between fat cells in a classic honeycomb or lacelike pattern. The other pattern observed in 24 of 40 cases (60%) exhibited a distinct multilayered pattern in which the bundles of slender spindle-shaped cells showed a predominantly parallel orientation to the skin surface. In four cases (10%), a mixture of both patterns was present. We conclude that the patterns of extension of dermatofibroma into the subcutaneous tissue are different from the patterns of dermatofibrosarcoma protuberans.

H-ras activation in benign and self-regressing skin tumors (keratoacanthomas) in both humans and an animal model system.

The involvement of the ras oncogenes in tumorigenesis was investigated in keratoacanthomas, which are benign and self-regressing skin tumors, both in humans and in a corresponding animal model system. Keratoacanthomas were induced on rabbit ears by repeated applications of 7,12-dimethylbenz(a)anthracene. About 60% of the tumor DNAs produced transformed foci after transfection into NIH 3T3 cells, and in all of them the transforming gene was identified as H-ras by Southern and Northern (RNA) hybridization. Immunoprecipitation experiments suggested that the transforming rabbit H-ras protein carried a mutation in codon 61. In addition, an activated H-ras gene was detected in a human keratoacanthoma by using a nude mouse tumorigenesis assay after transfection of tumor DNA into NIH 3T3 cells. This is the first report of ras activation in a benign human tumor. The transforming human H-ras gene showed a point mutation in codon 61 that would result in leucine instead of the glutamine present in the normal gene product. The finding of ras activation in tumors that are not only benign but also self-regressing indicates that activated ras genes are not sufficient to maintain a neoplastic phenotype, although they likely play a role in early stages of tumorigenesis.

Possible role of the bulge region in the pathogenesis of inflammatory scarring alopecia: lichen planopilaris as the prototype

Background:  Lichen planopilaris (LPP) is the prototype of scarring alopecias that mainly target the infundibuloisthmic (bulge) region of hair follicle. Hair follicle stem cells have been shown to reside in the bulge.

Immunoperoxidase technique modified by counterstain with azure B as a diagnostic aid in evaluating heavily pigmented melanocytic neoplasms

Heavily‐pigmented melanocytic neoplasms are difficult to evaluate on routine hematoxylin and eosin stained slides because pigmented melanocytes arc difficult to distinguish from the numerous melanophages that are usually seen in the background of these lesions. Immunoperoxidase staining for SI00 protein or HMB‐45 antibody using diaminobenzidine (DAB) as chromogen, which forms a brown product, does not adequately distinguish melanocytes from melanophages. We modified this technique by replacing hematoxylin as the counterstain with azure B, which stains melanin green‐blue. Thus, positive melanocytes appear brown while melanin granules in their cytoplasm are green‐blue. However, negative melanophages only stain green‐blue. This technique is useful in evaluating heavily pigmented melanocytic lesions such as malignant melanomas, melanosis of regressing malignant melanoma, residual malignant melanoma in areas of granulation tissue with melanophages, blue nevi, pigmented spindle cell variant of Spitzs nevi and combined

Bacillary angiomatosis in a child undergoing chemotherapy

Bacillary angiomatosis is an infectious disease of the skin and viscera characterized by vascular lesions, originally described in patients with human immunodeficiency virus infection. There are also case reports of bacillary angiomatosis occurring in immunocompetent patients and in noninfected patients with suppressed immune function. We report a case of bacillary angiomatosis in a child undergoing chemotherapy for acute leukemia.

Small malignant melanomas: Clinicopathologic correlation and DNA ploidy analysis

Among the various clinical and histologic criteria used to differentiate between benign and malignant melanocytic neoplasms, emphasis has been placed on the size of the lesion. Malignant melanomas, when diagnosed, are usually larger than 6 mm in diameter whereas most acquired melanocytic nevi tend to be smaller. We tested this size criterion with a retrospective clinicopathologic study of 30 proliferations of atypical melanocytes within the epidermis and dermis that measured less than 6 mm in diameter. Nineteen cases fulfilled all 15 established histologic criteria for the diagnosis of malignant melanoma. The remaining 11 cases fulfilled 14 of 15 criteria. Four of eight of these small malignant melanomas analyzed by multiparameter flow cytometry were aneuploid (DNA ploidy index less than or equal to 0.9 or greater than or equal to 1.1). The sex ratio, race, and anatomic sites associated with these small melanomas were similar to those described in patients with malignant melanomas larger than 6 mm in diameter. Furthermore, one melanoma metastasized to a regional lymph node and another recurred. We conclude that small malignant melanomas less than 6 mm in diameter can have histologic features, DNA abnormalities, clinical presentations, and biologic potentials similar to larger lesions.

Short-pulse carbon dioxide laser resurfacing in the treatment of rhytides and scars : A clinical and histopathological study

background. Previous studies have shown the efficacy of short‐pulse carbon dioxide (CO2) lasers in the treatment of rhytides and scars. To date, there have been few studies examining the histological aspects of these treatments. objective. The purpose of this study was to perform a prospective clinical and histopathological study of CO2 laser resurfacing for improvement of facial rhytides and scars. methods. A total of 23 patients were studied. Clinical improvement was evaluated both pre‐ and postoperatively using photographs and optical profilometry. Skin biopsies of rhytides were also obtained. results. Postoperatively, rhytides and scars both demonstrated significant increases in clinical improvement scores. Results from optical profilometry studies reflected these results. Skin biopsies from rhytides posttreatment demonstrated increases in collagen layer thickness. Improvement was sustained as late as 1 year following treatment. conclusions. Histopathological studies suggest improvement of rhytides and scars by CO2 laser resurfacing may be attributed to new collagen formation following treatment.

Multiple subcutaneous leiomyosarcomas in an adolescent with AIDS.

The case of 17-year-old boy with thalassemia major who contracted the human immunodeficiency virus (HIV) through multiple transfusions is described. Eight years after the onset of generalized lymphadenopathy, and 5 years after the documentation of HIV infection on serologic grounds, he developed the first of multiple, painful, subcutaneous nodules, which proved to be leiomyosarcomas of vascular origin. The histopathology and possible pathogenesis of these unusual tumors are discussed.

Clinical Relevance of Detection of Lymphovascular Invasion in Primary Melanoma Using Endothelial Markers D2-40 and CD34

Immunohistochemistry (IHC) using endothelial markers may facilitate the detection of lymphovascular invasion (LVI) in primary melanoma; however, the clinical implications of enhanced detection are unknown. We evaluated whether the use of lymphatic endothelial marker D2-40 and panvascular marker CD34 increases LVI positivity relative to routine histology alone and then evaluated the prognostic relevance of LVI detected using these markers in terms of disease-free (DFS) and overall survival (OS). A total of 246 primary melanomas were assessed for LVI using D2-40, CD34, and routine histology. Associations between LVI positivity and clinicopathologic variables, DFS, and OS were compared using univariate and multivariate analyses. The use of endothelial markers increased the rate of LVI positivity (18% using D2-40 and/or CD34 vs. 3% by routine histology, P<0.0001). On univariate analysis, IHC-detected LVI was significantly associated with more adverse clinicopathologic variables (thickness, ulceration, mitoses, and nodular subtype) compared with LVI detected by routine histology (thickness and ulceration only). In a multivariate model controlling for stage, LVI detected using IHC markers remained a significant marker of both reduced DFS [hazard ratio (HR), 2.01; 95% confidence interval (CI): 1.27-3.18; P=0.003] and OS (HR, 2.08; 95% CI: 1.25-3.46; P=0.005). Results show that D2-40 and CD34 increase the detection of LVI in primary melanoma and that cases missed by routine histology have prognostic relevance.

A clinical and histologic evaluation of two medium-depth peels : Glycolic acid versus Jessner's trichloroacetic acid

BACKGROUND. Chemical peels using alpha hydroxy acids have become one of the most frequently requested dermaiologic procedures. The use of glycolic acid in superficial chemical peels is now well established. However, the role of glycolic add in medium‐depth chemical peels has yet to be elucidated. OBJECTIVE. We performed a clinical and histologic comparison of 70% glycolic acid versus fessners solution as part of a medium‐depth chemical peel using 35% trichloroacetic acid (TCA). METHODS. Thirteen patients with actinic keratoses, solar lentigines, and fine wrinkling were evaluated praspectively. Each patient was treated with 70% glycolic acid plus 35% TCA (GA‐TCA) to the right face and Jessners solution plus 35% TCA (JS‐TCA) to the left face. Clinical and histologic changes were evaluated at 7, 30, and 60 days postoperatively. RESULTS. Clinically, the GA‐TCA peel was effective in treating photodamaged skin. The GA‐TCA peel was slightly more efficacious in removing actinic keratoses (clinical response score = 1.5) than the JS‐TCA peel (clinical response score = 1.0). His‐tologically, the GA‐TCA peel caused the formation of a slightly thicker Grenz zone (mean = 0.053 mm) 60 days postpeel than the JS‐TCA peel (mean = 0.048 mm) (not statistically significant). The GA‐TCA peel caused more neoelastagenesis than the JS‐TCA peel, while the JS‐TCA peel resulted in more papillary dermal fibrosis and neavascularization than the GA‐TCA peel. CONCLUSION. The GA‐TCA peel is a new medium‐depth chemical peel that is effective in treating photodamaged skin.