Neal S. Penneys

Eccrine angiomatous hamartoma (nevus): immunohistochemical findings and review of the literature

Eccrine angiomatous hamartoma (nevus) is a rare form of congenital tumorous malformation with proliferation of eccrine secretory coils and duels, surrounding capillary angiomatous channels and occasionally oilier minor elements. To date, there have been only about 24 cases reported in the literature. We report an additional case with more detailed description of the microscopic Endings, including immunohistochemical observations. The patient was a 28‐year‐old female who presented with painless, flesh to reddish brown‐colored, violaceous or bluish subcutaneous nodules on the extremities and trunk. The tumors did not show sweating following exertion. The histologic features were comparable lo the previously reported cases. The hamartomatous eccrine sweat glands and duels and a few apocrine glands demonstrated qualitatively diminished antigens commonly found in the eccrine sweat apparatuses, such as carcinoembryonic antigen (CEA) and S–100 protein. The. findings of CD34, CD44, human nerve growth factor receptor and Ulex europacus antigens have not been previously reported. The histologic features suggested a “hamartomatous” growth rather than a true neoplastic process.

Cylindroma expresses immunohistochemical markers linking it to eccrine coil

Nerve growth factor, S‐100 protein, CD44, and CD34 have unique expressions in or surrounding eccrine coil hut are not found in eccrine duct or apoerine gland. We studied 15 cases of cutaneous cylindroma to see if these antigens are found in this neoplasm. All were found in cylindroma to varying degrees. These results link the histogenesis of cylindroma to the eccrine coil. A unique feature of cylindroma is the large number of prominent dendritic cells most likely representing Langerhans cells that permeate the tumor aggregates.

The incidence of cancellation and nonattendance at a dermatology clinic.

BACKGROUND Same-day cancellation of appointments and nonattendance by patients can disrupt management of certain aspects of medical delivery and lead to inefficient allocation of resources and lost revenue. The frequency of cancellation and nonattendance at dermatology clinics has not been well documented. OBJECTIVE We measured same-day cancellation and nonattendance in a university dermatology clinic. METHODS We tabulated clinic attendees, same-day cancellations, and nonattendance for a 6-month period. We examined distribution by gender, type of payer, and clinic visit type (initial or follow-up). RESULTS Total same-day cancellation rate was 8.3%. Female patients canceled more frequently than male patients (9.2% vs 7.3%, P = .02). Cancellation rates were similar for initial and follow-up visits. The nonattendance rate was 17% with the highest rates found in state-supported categories (26%) and the lowest in commercial insurance programs (13%). Nonattendance rates did not vary significantly by gender or visit type. CONCLUSION Same-day cancellation and clinic nonattendance is a significant factor in the efficient fiscally sound management of a busy dermatology clinic. The risk of nonattendance is assumed by physicians and seems to be correlated with payer type.

CD44 expression in Merkel cell carcinoma may correlate with risk of metastasis

We retrospectively studied 25 cases of cutaneous primary, locally recurrent or metastatic Merkel cell carcinoma to see if expression of the cell surface marker CD44 correlated with metastatic potential. In 3 of 6 cases in which metastasis was documented, CD44 was found on membranes of tumor cells. Three cutaneous lesions associated with local metastasis did not express CD44. Three primary tumors expressed CD44 but had not disseminated at the time of this report; follow‐up after excision of the primary lesion in these cases was less than (5 months. None of the primary or locally recurrent Merkel cell carcinomas followed longer than 6 months (14 of 19 cases) expressed CD44. We conclude that expression of CD44 in Merkel cell carcinoma may eventually be of some value in the assessment of prognosis of cutaneous Merkel cell carcinoma.

CD44 expression in normal and inflamed skin.

CD44 is the principal cell surface receptor for hyaluronate. In non‐inflamed skin, CD44 expression is limited to the cell membrane of eccrine coil cells. The distribution on these cells is assymetric, with intense staining on the dermal side and little staining on the luminal side of the coil cell. In skin containing a pathologic process, either inflammatory or neoplastic, CD44 expression can be widespread on the membranes of keratinocytes and on infiltrating lymphocytes in the vicinity of the process. Diverse roles have been proposed for CD44 and largely involve aspects of cellular adhesion in one setting or another. CD44 may identify a more mobile, proliferating keratinocyte that is responding to local injury. In eccrine coil, the stable presence of CD44 on the non‐luminal surface of secretory cells indicates an undefined function for CD44 in the generation of eccrine sweat.

Expression of proliferating cell nuclear antigen in Spitz nevus

BACKGROUND Epithelioid and spindle cell nevus (ESN; Spitz nevus) is a histologically well-described entity. We hypothesized that the features of ESN may reflect activation by a proliferative stimulus. OBJECTIVE Nevocytes and keratinocytes in ESN and control specimens were examined for expression of the proliferation marker, proliferating cell nuclear antigen (PCNA). METHODS Standard immunohistochemical methods were used to examine the expression of PCNA in a series of ESN, other nevi, and malignant melanoma. RESULTS PCNA was detected in nevocytes in a significant percentage of ESN but not in other nevi. PCNA expression was increased in basilar keratinocytes in ESN when compared with staining of basilar keratinocytes in normal epidermis. In other melanocytic nevi and noninflamed melanoma, PCNA expression in keratinocytes was similar to that in normal control tissue. CONCLUSION Increased PCNA labeling in nevocytes and keratinocytes in ESN suggests that a growth stimulus, present within some of these lesions, affects both keratinocytes and nevocytes.

ANIMAL MODELS FOR TESTING TOPICAL CORTICOSTEROID POTENCY: A REVIEW AND SOME SUGGESTED NEW APPROACHES

Animal models allow for testing the potency of topical corticosteroids by measuring their effects on induced conditions that are analogous to human skin disease. Animal models can examine the anti‐inflammatory, anti‐allergic, antiproliferative, and atrophogenic effects of topical corticosteroids. These test models as they are currently applied are relatively imprecise; however, innovations using newly available histologic, autoradiographic, and biochemical techniques have great potential for precisely quantitating the effects of corticosteroids in animal model systems.

Metastatic prostatic carcinoma histologically mimicking malignant melanoma

Prostatic carcinoma rarely metastasizes to the skin. We describe a case in which inguinal metastasis occurred. Histologically, the tumor was composed of pale‐staining cells which had pronounced epidermotropism, producing a pagetoid pattern mimicking that seen in malignant melanoma. The diagnosis was confirmed by demonstrating prostatic specific antigen in tumor cells.

Cutaneous histopathology of Conradi-Hunermann syndrome

The histopathology of the skin in the ichthyosiform erythroderma associated with classical Conradi‐Hunermann syndrome has been rarely described. Skin biopsies from 2 infants with the classical features of Conradi‐Hunermann syndrome including ichthyosiform erythroderma contained hyperkeratosis, dilated ostia of pilosebaccous structures, and calcium salts in the stratum corneum detectable with special stains. An unusual feature of one case was dilatation of acrosyringeal structures. We hypothesize that dilatation of acrosyringeal structures is analogous to the plugging noted in pilosebaceous units. Taken together, the ichthyosiform erythroderma of Conradi‐Hunermann has a distinctive histologic appearance.

Cystic clear cell acanthoma

An histologically typical clear cell acanthoma was identified forming a cystic structure. The finding of clear cell acanthoma within a cyst is histologically unique.