Jorge L. Sánchez

Melasma: A clinical, light microscopic, ultrastructural, and immunofluorescence study

Melasma is an acquired brown hypermelanosis of the face. Although it is thought that melasma is associated with multiple etiologic factors (pregnancy, gastric, racial, and endocrine), one of the primary causes of its exacerbation appears to be exposure to sunlight. Three patterns of melasma are recognized clinically: (1) a centrofacial pattern, (2) a malar pattern, and (3) a mandibular pattern. Examination of patients with Woods light (320--400 nm) is useful in classifying the specific type of melasma in correlation with the localization of pigment granules (melanosomes) in the epidermis and dermis. Four types of melasma are described on the basis of Woods light examination: (1) an epidermal type, (2) a dermal type, (3) a mixed type, and (4) a fourth type, described in patients of dark complexion, in which the lesions, for lack of contrast, are not discernible on Woods light examination, perhaps due to the increased number of melanosomes in the normal skin of black individuals. Light, histochemical, and electron microscopic studies revealed an increase in number and activity of type-specific melanocytes which appeared to be engaged in increased formation, melanization, and transfer of pigment granules (melanosomes) to the epidermis as well as to the dermis. The melanocyte seems to undergo a functional alteration brought about by a combination of multiple factors, including persistent sun exposure, hormonal factors, and genetic predisposition.

Malignant Neoplasms Associated with Seborrheic Keratoses: An Analysis of 54 Cases

The association of malignant neoplasms arising contiguous with or adjacent to seborrheic keratoses has been previously documented. In this study a retrospective analysis was performed to further characterize these combined neoplasms. A total of 54 examples of malignant neoplasms in conjunction with seborrheic keratoses were found, of which 43 were basal cell carcinomas, six were Bowens disease, three were keratoacanthomas, and two were malignant melanomas. The average age of the patients was over 65 years. Men were affected more frequently then women. The posterior thorax was the most common site for malignant neoplasms associated with seborrheic keratoses. The superficial type of basal cell carcinoma was the most common type of basal cell carcinoma found in this association. All subtypes of seborrheic keratosis may be found together with malignant neoplasms. We believe the appellation collision tumor is not valid because it is unknown whether the association of seborrheic keratoses with malignant neoplasms is a random event or whether there is, in fact, a pathogenic relationship in the development of two distinctive neoplasms together. Therefore, the term compound tumor is proposed to designate the finding of two distinctive neoplasms either directly contiguous with each other or immediately adjacent to each other.

Prevalence and clinical spectrum of skin diseases in kidney transplant recipients

Cutaneous lesions can be a significant problem in kidney transplant recipients. Factors such as climate and skin types have been implicated as modifiers of these clinical manifestations. With the purpose of determining the prevalence and clinical spectrum of skin diseases in a group of Hispanic kidney transplant recipients in a tropical climate, 82 serial unselected patients were examined. Seventy-eight were found to have some type of skin disease. Infections of the skin were the most common, followed by drug-induced changes and malignant or premalignant cutaneous tumors. Except for the preponderance of superficial mycotic infections, the overall results in our population are in agreement with other series.

Prevalence of dermatophytosis in patients with diabetes

BACKGROUND Controversy still exists as to whether dermatophytic skin infection is truly more common in patients with diabetes. OBJECTIVE The purpose of this study was to determine the true prevalence of dermatophytosis in diabetic patients as compared with a control population. METHODS One hundred consecutive diabetic patients were examined for evidence of fungal disease of the skin and compared with nondiabetic, nonimmunocompromised patients. Potassium hydroxide preparation and fungal cultures were obtained from all suspect lesions. RESULTS Thirty-one percent of the diabetic population had culture-proven fungal infections compared with 33% of the control group. The organism most commonly isolated was Trichophyton rubrum in both groups, and the feet were the most common site of infection. Candida albicans was more prevalent in the control group, affecting the nails in particular (24% vs 15% in the diabetic patients). CONCLUSION This study shows that there does not seem to be an increased prevalence of dermatophytosis in diabetic patients as compared with a control, nondiabetic patient.

Tumid lupus erythematosus.

BACKGROUND Tumid lupus erythematosus (TLE) is a subtype of discoid lupus erythematosus (DLE) whose clinical characteristics rarely have been described in the literature. OBJECTIVE To describe the clinical, histopathologic, and other laboratory findings in tumid lupus erythematosus. METHODS Clinical and laboratory findings were reviewed in four patients who had been diagnosed with tumid lupus erythematosus by conventional microscopy. The diagnoses were characterized by a superficial and deep perivascular infiltrate of lymphocytes and deposits of mucin in foci in the reticular dermis. RESULTS All four patients were young women. Ages ranged from 16 to 39 years (mean 21 years). The lesions consisted of numerous erythematous papules and plaques, some with annular configuration situated in the face and neck, trunk, and upper extremities. All four patients had concurrent lesions of classic DLE, three of them had systemic lupus erythematosus (SLE). Direct immunofluorescence test results were negative in nonexposed lesional skin of two of the patients. CONCLUSION The clinical findings of concurrent lesions of TLE and classic DLE in the same patient, the presence of lesions of TLE in patients with SLE, and the histologic findings demonstrate that TLE is a distinct manifestation of DLE, and as such, a cutaneous expression of SLE.

Histopathologic differentiation between localized and systemic scleroderma

It is widely accepted that a histopathologic differentiation between localized scleroderma (LS) and systemic scleroderma (SS) is not always possible. With the objective of identifying differentiating histopathological features between them, 32 cases of LS and 19 cases of SS were reviewed. Histological features such as the distribution, composition, and density of the inflammatory cell infiltrate, thickness of the dermis, alterations of dermal collagen, and the presence of calcification were evaluated in each case. On the basis of our observations, LS and SS can be differentiated usually by the distribution and density of the inflammatory infiltrate and by the involvement of the papillary dermis. Inflammatory changes are more prominent in LS than in SS. Sclerosis of the papillary dermis is frequently seen in LS but is absent in SS.

Spirochetal forms in the dermal lesions of morphea and lichen sclerosus et atrophicus.

Morphea and lichen sclerosus et atrophicus are cutaneous diseases that are manifest by an early edematous stage, followed later by sclerosis and atrophy. They share features with acrodermatitis chronica atrophicans and erythema chronicum migrans, diseases that have been linked to infection by the spirochete Borrelia burgdorferi. A modified silver stain was used to identify the presence of spirochetes in skin biopsy specimens of patients with morphea and lichen sclerosus et atrophicus. Spirochetal forms were identified in the lesional skin of 10 of 25 patients with morphea and in 10 of 21 cases of lichen sclerosus et atrophicus. These spiral forms of bacteria had a significant tendency to occur in early and fully developed lesions of morphea and in early lesions of lichen sclerosus et atrophicus, whereas they tended to be absent in lesions demonstrating late pathological changes.

Granular cell leiomyosarcoma of the skin

A case is presented of a multifocal malignant neoplasm involving the skin of the upper back in a 10-year-old boy following radiation therapy to the head and neck for a cerebellar medulloblastoma. Histologically, the neoplastic cells were remarkable for the presence of abundant periodic acid-Schiff (PAS)-positive diastase-resistant intracytoplasmic eosinophilic granules. Immunoperoxidase procedures revealed strong positive staining of the tumor cells with desmin, vimentin, and smooth muscle myosin antibodies, and negative staining for myoglobin, S-100 protein and keratin, thus supporting a smooth muscle line of differentiation for this neoplasm. Electronmicroscopy demonstrated numerous intracytoplasmic autophagic vacuoles that corresponded to the granules observed under the light microscope. Leiomyosarcoma should be entertained in the differential diagnosis of poorly differentiated cutaneous neoplasms histologically characterized by a proliferation of cells containing abundant granular eosinophilic cytoplasm.

ORGAN-SPECIFIC AUTOANTIBODIES IN VITILIGO PATIENTS AND THEIR RELATIVES

Background. Recent data have supported an autoimmune etiology of vitiligo. Genetic factors also seem to play an important role in this disorder. The purpose of this study was to determine the presence and frequency of organ‐specific autoantibodies in vitiligo patients and their relatives.

DNA repair and nonmelanoma skin cancer in Puerto Rican populations

BACKGROUND UV radiation is a risk factor for nonmelanoma skin cancer (NMSC). The relation between DNA damage and oncogenesis suggests that diminished DNA repair capacity (DRC) is involved in tumorigenesis. OBJECTIVE The purpose of this study was to test the hypothesis that a low DRC is a susceptibility factor for the development of NMSC in Puerto Rico. METHODS A case-control retrospective clinical study was done to compare the age-adjusted DRC in participants with and without NMSC. DRC was measured using a host cell reactivation assay with a luciferase reporter gene irradiated with UV light and transfected into human peripheral lymphocytes. An epidemiologic questionnaire was used to solicit risk factors. RESULTS The mean (+/-2 SE) DRC of 177 control patients without skin cancer was 8.6% +/- 0.7. Participants (280) with NMSC had a 42% lower DRC (5.0% +/- 0.3). CONCLUSION A low DRC is a susceptibility factor for NMSC.