Premalignant Skin Lesions Research Articles

Premalignant and neoplastic skin lesions associated with occupational exposure to "tarry" byproducts during manufacture of 4,4'-bipyridyl.

ABSTRACT Skin lesions have been identified in 20 workers manufacturing 4,49-bipyridyl. The lesions were on the face, neck, and backs of the hands and arms. Larger localised lesions were removed surgically and examined histopathologically, but other lesions have been treated topically with fluorouracil cream. Histological diagnosis showed a progression from keratosis to Bowen9s disease and, in six cases, to squamous cell carcinoma. Over 550 individuals associated with 4,49-bipyridyl processes between 1961 and 1980 have been examined or questioned. All 20 patients identified worked in now obsolete production plants; 15 of whom were found among the 147 shift process operators. The time taken for the lesions to appear from first working on a 4,49-bipyridyl plant was 6-19 years (average 12 years). Starting in the early 1960s three processes have been successively used to convert pyridine into 4,49-bipyridyl. These differ in the reaction conditions used and in the efficiency of the conversion. In the two earlier plants a substantial quantity of pyridine was converted into polypyridyls and “tarry” byproducts, which caused operating difficulties and increased the risk of worker exposure. The exposure and occupational histories of the cases, including the fact that two had worked only on the obsolete production plants, indicates that the causative agent was present in these earlier processes. In-vitro tests for potential carcinogenicity on materials from the present plant and from an earlier process gave positive tests on the tarry byproducts from the earlier process, suggesting that they were the cause of the lesions. Tar impurity production on the present plant is minimal, and worker exposure to chemicals is low. No similar skin lesions have been seen in those who have worked only on the present plant. This observation supports the view that the causative agent was present only on the earlier plants but is not conclusive because of the shorter time that has elapsed since first exposure of personnel who have worked only on the present plant. Medical surveillance of past and present 4,49-bipyridyl workers is continuing.

Loss of beta2 microglobulin from the cell surface of cutaneous malignant and premalignant lesions.

Biopsies from twenty-three patients with malignant skin lesions and from twenty-two patients with premalignant or benign skin lesions were stained for beta2 microglobulin by use of the immunoperoxidase technique. The results showed a significant loss of demonstrable surface beta2 microglobulin from the surface of malignant cells compared to benign, and a partial loss in the premalignant cases. This difference could prove to be a useful tool in the histological diagnosis of malignant skin lesions, and in assessing whether or not the lesion has been completely excised.

Basal cell carcinoma in a hair transplant recipient site

A basal cell carcinoma developed in the central scalp of a forty-one year old man at the recipient site of a hair transplant plug that was placed five years previously. The patient was never noted to have premalignant or other malignant skin lesions. Although the relationship is probably coincidental, medico-legal factors dictate consideration of a cause and effect relationship.

A Two-Year Experience With a Series of Rural Skin and Oral Cancer Detection Clinics

Farmers and ranchers are more prone to develop skin cancer as an occupational hazard. In order to promote early detection of premalignant and malignant skin lesions a number of skin and oral cancer detection clinics were held in rural communities in central Virginia. The results of these clinics were very gratifying with an overall detection rate of 21.6% premalignant or malignant lesions in the population examined.

Tumors of the skin. XII. Topical 5-Fluorouracil for epidermal neoplasms.

AbstractOur studies have been carried out in over 500 patients with an aggregate of more than 15,000 lesions for observation periods in excess of 5 years. Topical chemotherapy with 5‐FU was shown to result in selective eradication of premalignant and superficial malignant lesions of the skin. Since the action of 5‐FU is selective, it produces minimal or no effects on normal tissues adjacent to tumors. Healing therefore occurs with slight or no apparent scarring. Topical chemotherapy is indicated for solar keratoses and other precancerous lesions as well as for multiple superficial primary skin cancers when standard therapeutic measures are not suitable because large areas of the skin are involved by persistently developing tumors. Topical cancer chemotherapy induces the resolution of premalignant skin lesions and prevents their further development to the malignant stage. Early primary skin cancers and premalignant lesions react to topical antitumor agents before they are otherwise clinically detectable. These tumors can therefore be eradicated before they present significant clinical problems. Early detection and eradication of skin cancers and premalignant skin lesions furthermore result in the reduction of the subsequent incidence of clinically significant tumors. Local chemotherapy therefore appears to have prophylactic value. Local administration of 5‐FU results in high concentrations of the antitumor agent at the tumor site, although the total amount administered and the rate of absorption are relatively low. General toxicity such as bone marrow depression and other systemic side‐effects are therefore not encountered with local cancer chemotherapy. Superficially located neoplasms are suitable model systems for the study of tumor biology. Local chemotherapy indicates that differential and selective chemical effects can be produced in neoplastic cells and their normal counterparts. Studies on local chemotherapy demonstrate that the selective eradication of malignant disease in many by chemical means is feasible.

Experiences with local chemotherapy and immunotherapy in premalignant and malignant skin lesions.

Local chemotherapy with 5-FU was investigated in premalignant and superficial malignant skin lesions in more than 700 patients. Resolution of neoplasms occurred in more than 95% of patients and lasted for observation periods of up to 6 years. Healing took place without perceptible scarring and with restoration of normal color and texture of the skin. Local side effects were minor. Systemic toxicity did not occur. Several agents, with and without cystostatic activities, produce immune reactions which are more intense at sites of epidermal premalignant and malignant neoplasms than in the normal tissues. More than 50 patients have been studied by this immunotherapeutic approach with results essentially similar to those obtained by topical chemotherapy. Chemotherapy and immunotherapy differ completely in their mechanisms of action. The 2 methods are presented as entirely different modalities, which give essentially similar results. Immunotherapy is still in the investigative stages while local chemotherapy constitutes a modality for the management of extensive skin lesions for which there has been no satisfactory treatment until now.

A Characterization of Basophilic Degeneration of Collagen by Histochemical and Microspectroscopic Procedures

Basophilic degeneration of dermal collagen is a histologie feature of senile atrophy of the skin. It is frequently seen in association with premalignant and malignant skin lesions (1). The purpose of this paper is to compare normal dermal collagen with dermal collagen exhibiting basophilic degeneration by means of a battery of histochemical procedures and by a microspectroscopic procedure.