Dermatologic electrosurgery in patients with implantable cardioverter-defibrillators and pacemakers.

BACKGROUND: Electrosurgery is frequently employed in the treatment of skin cancer and other dermatologic conditions in the elderly. Implantable cardioverter-defibrillators (ICDs) and pacemakers are most commonly seen in this older population. Potentially hazardous electrosurgical interference exists with the function of ICDs and pacemakers in this setting. OBJECTIVE: Our goal is to review the potential hazards of electrosurgery in patients with ICDs and pacemakers and to suggest a perioperative management plan. METHODS: Review of the medical literature on electrosurgical interference with ICDs and pacemakers was accomplished in addition to a case report of ventricular tachycardia during Mohs surgery on a patient with an ICD. RESULTS: Multiple case reports and reviews from the nonder-matologic literature demonstrate that a real hazard exists. CONCLUSION: Knowledge of the potential electrosurgical interference with ICDs and pacemakers is required to perform these procedures safely. A perioperative management plan is suggested.

Intradermal nodular fasciitis presenting as an eyelid mass.

BACKGROUND: Nodular fasciitis is a fibroblastic proliferation in which nodules, most commonly appearing on the extremities, develop suddenly and rapidly. Although excisional biopsy is curative, the nodules will often resolve spontaneously; however, the histologic appearance of a pleomorphic spindle cell neoplasm with frequent mitotic figures may raise concern of a more malignant neoplasm and lead to unnecessary and overly aggressive therapy. METHODS: A case of nodular fasciitis presenting in an unusual location, intradermally at the lateral canthus, is discussed. RESULTS: Review of the recent literature from other disciplines reveals new insights into the etiology and diagnostic options (fine needle aspiration, tomography, other imaging techniques) for this puzzling disease. CONCLUSIONS: When nodular fasciitis occurs in an unusual location, such as on the head and neck or at an intradermal location, it will not present as the deep, mobile, nontender nodule described in the dermatologic literature. Fine-needle aspiration and modern imaging techniques may help in the diagnosis and prevent unnecessary surgery for a self-limited condition.

Rudimentary meningocele presenting with a scalp hair tuft. Report of two cases.

BACKGROUND: Rudimentary meningoceles represent a developmental anomaly in which meningothelial elements are found in the skin. The majority of rudimentary meningoceles occur on the scalp over the occiput or along cranial suture lines. They are usually recognized at birth and present as a pink papule or nodule or an area of alopecia. OBSERVATIONS: We present two patients who presented with a scalp hair tuft at birth over a rudimentary meningocele. This finding has not been previously reported. CONCLUSIONS: Rudimentary meningoceles are uncommon developmental anomalies that are of clinical importance due to the occasional presence of connection to the central nervous system. Due to this potential for central nervous system connection, any midline lesion in an infant, including midline hair tufts, deserves careful preoperative evaluation including imaging studies.

Phase contrast microscopy for identifying epidermal margins in unstained cryosections for Mohs micrographic surgery.

BACKGROUND: Mohs fresh tissue micrographic surgery has been accepted as the most reliable therapeutic modality for the eradication of recurrent cutaneous malignancies or those skin cancers that are difficult to treat otherwise. OBJECTIVE: We have developed a method to ascertain the presence of the epidermis and other edges in the tissue sections before staining the cryosections and microscopically searching them for cancer cells. METHODS: Our method for screening the cryosections for the epidermis can be done quickly and easily using relatively inexpensive phase contrast optics. RESULTS: Use of this method allows easy visualization of freshly cut cryosections, especially the presence of the epidermis and other edges of the tissue, in just a matter of seconds instead of a half hour to stain and recut the sections. CONCLUSIONS: Phase contrast microscopy and/or dark field illumination are instrumental in screening unstained cryosections for the presence of the tissue borders, especially the epidermis, before they are stained with hematoxylin and eosin. This method saves a great deal of time and effort both for the surgeon and the patient.

H-ras-1 gene mutations in basal cell carcinoma: automated direct sequencing of clinical specimens.

Ras oncogenes are activated by point mutations occurring in codons 12, 13 or 61 and almost any base pair mutation occurring within the first two positions of any of these codons results in activation of the gene. Although ras point mutations have been reported to occur in several skin neoplasms including squamous carcinoma, keratoacanthoma and melanoma, their frequency of occurrence in basal cell carcinoma is not known. We examined basal cell carcinomas from 13 patients for activating mutations in the H-ras-1 gene by automated direct sequencing of polymerase chain reaction assay amplified targets. We amplified sequences in exon 1 that flanked codons 12 and 13 and amplified sequences in exon 2 that flanked codon 61. The PCR products were centrifuged and directly sequenced using antisense primers in an automated sequencer using fluorescent dideoxyterminators. One tumor was found to show an activating G to A transversion in codon 13 which code for aspartic acid instead of glycine. Although H-ras mutations may be found in some skin tumors, they are not frequent in basal cell carcinomas. From this study we believe that direct sequencing of clinical material is of value and has advantages over other techniques. Additional studies need to be undertaken to understand the true clinical significance of ras mutations in basal cell carcinomas when they occur.

Iontophoresis of lidocaine for anesthesia during pulsed dye laser treatment of port-wine stains.

Port-wine stains may be effectively ablated using the pulsed dye laser emitting at a wavelength of 577 or 585 nm. However, the discomfort of this therapy may be severe enough to require reduction of treatment duration thereby increasing the need for repeat sessions. Currently available methods of anesthesia or sedation for pulsed dye laser therapy have drawbacks to their use. We performed a prospective double-blind, placebo-controlled evaluation of the iontophoresis of lidocaine HCl 4% and lidocaine HCl 4% with epinephrine 1:50,000 for local anesthesia during pulsed dye laser ablation of port-wine stains. Eleven patients with port-wine stains completed the initial phase of the study. Pain scale evaluation by patients demonstrated significant decreases in the discomfort of pulsed dye laser impulses by the iontophoresis of lidocaine HCl 4% and lidocaine HCl 4% with epinephrine 1:50,000 (P less than .0001), with no significant difference between these treatments. Follow-up evaluation suggests that iontophoresis has no detrimental effect on pulsed dye laser ablation of port-wine stains, despite significant decreases in perfusion, as measured by laser Doppler velocimetry, of port-wine stain areas receiving iontophoresis of lidocaine with epinephrine. Iontophoresis of lidocaine HCl 4% with or without epinephrine is a safe and effective method of local anesthesia for pulsed dye laser therapy.

Nodular cutaneous B-cell lymphoma of the scalp in the acquired immunodeficiency syndrome.

Aggressive B-cell non-Hodgkin's lymphoma frequently complicates human immunodeficiency virus type 1 infection. Although extranodal disease is an important feature of this condition, the incidence of cutaneous involvement has not been determined. A review of 754 published cases of B-cell non-Hodgkin's lymphoma associated with human immunodeficiency virus type 1 revealed an incidence of cutaneous extranodal involvement of 8.2%, approximately equal to that seen in non-Hodgkin's lymphoma not associated with human immunodeficiency virus. Lymphoma was the initial manifestation of acquired immunodeficiency syndrome in two thirds of these cases. In particular, although the head and neck are commonly involved in non-Hodgkin's lymphoma not associated with human immunodeficiency virus, scalp involvement is uncommon in human immunodeficiency virus-associated B-cell non-Hodgkin's lymphoma, and we report the second case. The natural history and proposed pathogenesis of human immunodeficiency virus-associated non-Hodgkin's lymphoma are discussed.

Pharmacologic therapy for urticaria.

Treatment of chronic urticaria presents a challenge to both practitioner and patient. Traditional H1 antagonists with good efficacy but substantial side effects are being supplanted in many cases by nonsedating H1 antagonists such as terfenadine and astemizole. Antidepressant medications and combinations of H1 and H2 antagonists offer improved results for selected patients. Further development and investigation of mast cell stabilizers and inhibitors of urticaria mediators other than histamine hold promise. A better understanding of the underlying pathogenesis remains the greatest hope of formulating rational and effective therapy.

Congenital midline nasal masses: diagnosis and management.

Congenital midline nasal masses (CMNMs) are rare lesions most commonly caused by dermoids, hemangiomas, nasal gliomas or encephaloceles. We report a case of nasal glioma and discuss the embryologic development, evaluation, and management of such CMNMs.

Respiratory frequency and the oxygen cost of exercise.

Although many studies indicate that the spontaneous breathing frequency minimizes breathing work, the consequences of this for exercise energetics have never been investigated. To see if the spontaneous exercise breathing frequency minimizes oxygen uptake, we compared VO2 during treadmill walking (2/3 VO2 max) at several alternative frequencies. The alternative frequencies ranged from the lowest sustainable to a frequency twice the spontaneous value. All eight subjects adjusted tidal volume to comfort. Exercise oxygen uptake was constant, independent of breathing frequency. At the same time, minute ventilation rose to be 65% greater at the highest frequency than at the lowest (P less than 0.01). We then reproduced the various exercise frequencies, tidal volumes, and ventilations during seated isocapnic hyperpnea to measure VO2 with locomotory muscles at rest. Once again, oxygen uptake was constant, independent of breathing frequency. We conclude that the spontaneous exercise breathing frequency fails to minimize VO2 during either exercise or resting reproduction of exercise ventilation.