Copyright 2003 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.2003
Sentinel lymph node mapping and excision is commonly suggested for patients with malignant melanomas (MMs) that exceed 1 mm in depth. Surgical manipulation of the primary MM site may cause scarring and subsequent alteration of lymphatic drainage patterns. Preoperative sentinel lymph node mapping represents the ideal procedure but requires a noninvasive means of determining primary MM depth to exclude those patients with thinner lesions. Pellacani and Seidenari used echographic, clinical, and videomicroscopic criteria to develop an algorithm that allows accurate preoperative differentiation between MMs that are thinner and thicker than 1 mm.
The increased incidence of aggressive cutaneous malignancies in organ transplant recipients is well recognized. This retrospective analysis by Martinez et al of 68 organ transplant recipients with 73 distinct metastatic skin cancers reveals that the primary tumors were predominantly squamous cell carcinomas and that the head and neck were the most common sites of metastatic disease. As the number of transplant patients continues to rise and their lives are extended with a wide range of immunosuppressant medications, the need for careful and aggressive management of nonmelanoma skin cancers in this population will become even more essential.
Dermoscopy is a simple, in vivo method to aid in the differential diagnosis of pigmented skin lesions, including malignant melanoma. Using an oil immersion technique and optical magnification, structures not visible to the naked eye can be discerned. Braun et al used a 1-mm micropunch in areas of dermoscopic interest to mark sites within excised specimens for subsequent histopathologic examination, for the first time allowing precise localization and direct correlation of dermoscopic features with histopathologic findings.
Porphyria cutanea tarda (PCT) is a hepatic porphyria associated with impaired function of the enzyme uroporphyrinogen decarboxylase in the liver. Overproduction of heme precursors produces a light-sensitive dermatitis and excess urinary porphyrin excretion. Clinical expression of PCT typically requires inducing agents or conditions, of which excess tissue iron associated with the presence of hereditary hemochromatosis genes (HFE) is one. In this longitudinal study of 62 patients with PCT, Stölzel et al found that most carried HFE mutations. Clinical remission in chloroquine-treated patients was limited to those patients with wild-type HFE, suggesting that phlebotomy is a more appropriate first-line treatment for those patients with PCT and HFE mutations. Analysis of HFE mutation may prove useful in evaluating the probability of responsiveness to chloroquine therapy in PCT.
Lidocaine hydrochloride is the preferred local anesthetic agent used in outpatient surgical procedures. Although quite rare, hypersensitivity reactions may occur with the use of any local anesthetic, even amino amide agents such as lidocaine. Type IV reactions are even exceedingly rarely reported. In this case series, Mackley et al provide evidence that delayed-type hypersensitivity to lidocaine is more common than previously recognized. They describe a practical approach for managing these patients that stresses the importance of intradermal challenge.
This Month in Archives of Dermatology. Arch Dermatol. 2003;139(3):265. doi:10.1001/archderm.139.3.265