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Timothy M Johnson

Publications and source records attributed to Timothy M Johnson.

54 records · Page 3Linked to original sources
PubMed2004

Evaluation of staging chest radiographs and serum lactate dehydrogenase for localized melanoma.

BACKGROUND: Radiographic and laboratory evaluations are often routinely used in the initial work-up for melanoma. PURPOSE: To examine the yield of a chest radiograph and serum lactate dehydrogenase (LDH), in the work-up for newly diagnosed localized melanoma. METHODS: Patients with a new diagnosis of localized invasive melanoma were entered into a prospective database. The status of the chest radiograph, LDH, and sentinel lymph node (SLN) was assessed. RESULTS: Two-hundred-twenty-four patients were entered into the study and 210 had chest radiograph data for analysis. The true positive chest radiograph rate, defined as the percent of chest radiographs interpreted as "positive or equivocal possibly melanoma related" with subsequent confirmed melanoma metastases, was 0%. The false positive chest radiograph rate, defined as the percent of chest radiographs interpreted as "positive or equivocal possibly melanoma related" with melanoma metastases excluded based on previous or subsequent studies or other known medical conditions, was 7%. Ninety-six patients (melanoma> or =1 mm) had LDH results for analysis. Elevations in LDH were found in 15% and did not lead to detection of occult disease in any patients. Seventy-seven patients underwent SLN biopsy. A positive SLN did not correlate with abnormal chest radiograph or LDH. CONCLUSION: Low yield, high rate of false-positive tests and lack of significant impact of early detection of metastases on survival argue that chest radiographs and serum lactate dehydrogenase should probably not be accepted into routine clinical practice in patients with clinically localized melanoma in the absence of data supporting their use.

Adolescent↗
PubMed2004

Tretinoin treatment before carbon-dioxide laser resurfacing: a clinical and biochemical analysis.

BACKGROUND: Tretinoin is often prescribed before laser resurfacing in an attempt to enhance results. OBJECTIVE: We sought to assess the clinical and biochemical effects of preoperative tretinoin use before laser resurfacing. METHODS: Patients were randomized to apply tretinoin to one forearm and placebo to the other for 3 weeks. Patients' photodamaged forearms were focally treated by carbon-dioxide laser resurfacing. Biopsy specimens were obtained at baseline and various times posttreatment. Real-time polymerase chain reaction technology was used to quantify messenger RNA levels of types I and III procollagen and matrix metalloproteinases-1, 3, and 9. Wounds were assessed for degree of re-epithelialization using a computer graphics-generated template. A colorimeter was used to quantify postoperative erythema. RESULTS: No substantial differences in either biochemical markers or clinical end points were identified between tretinoin and placebo pretreated forearms. CONCLUSIONS: We found no evidence of enhanced collagen formation, accelerated re-epithelialization, or quicker resolution of postoperative erythema with tretinoin pretreatment before laser resurfacing.

Administration, Cutaneous↗
PubMed2004

Vulvar melanoma: review of diagnosis, staging, and therapy.

OBJECTIVES: To update, assimilate, and bridge the contemporary literature on vulvar and cutaneous melanoma regarding diagnosis, staging, and therapy to provide a useful clinical reference for managing and counseling for affected patients. MATERIALS AND METHODS: A computerized search for reports in the literature up to June 2003 was carried out using PubMed and MEDLINE databases. Multidisciplinary involvement was used in evaluating the available data and formulating conclusions. RESULTS: More than 300 reports were reviewed. Diagnosis, staging, and therapy aspects of vulvar melanoma are summarized. CONCLUSIONS: Vulvar melanoma represents a subtype of cutaneous melanoma, with similar prognostic and staging factors. The most recent American Joint Committee on Cancer staging system for cutaneous melanoma is applicable to vulvar melanoma. Sentinel lymph node biopsy is reliable for staging the regional lymph node basin for vulvar melanoma. Standardized documentation of clinical and histopathologic parameters is needed to standardize grouping of cases for future comparison studies.

Journal Article↗
PubMed2004

Guidelines for the management of squamous cell carcinoma in organ transplant recipients.

BACKGROUND: Solid-organ transplant recipients have a high incidence of cutaneous squamous cell carcinoma (SCC) and often develop multiple and aggressive tumors. There are few published studies or reviews, which provide guidance to the clinician in the treatment of these patients. OBJECTIVE: The objective was to develop useful clinical guidelines for the treatment of skin cancer in organ transplant recipients (OTRs). METHODS: The members of the Guidelines Committee of the International Transplant-Skin Cancer Collaborative (ITSCC) carried out a computerized search utilizing the databases of the National Library of Medicine for reports in the literature on SCC in OTRs. These reports were collectively examined by the group and combined with experiences from the members' clinical practices in the development of the guidelines. RESULTS: More than 300 articles relating to SCC in OTRs were reviewed. In general, reports concerning the prevention and treatment of SCC in OTRs are of individual cases or small case series. They are retrospective in nature, statistically nonrigorous, and lack the complete epidemiologic data necessary to derive definitive conclusions. Combining these studies and collective clinical experience, however, is at present the best available method for devising guidelines for the treatment of SCC in OTRs. CONCLUSION: Guidelines developed for the treatment of skin cancer in OTRs, supported by the best available data and collective clinical experience, may assist in the management of OTRs with SCC. The development of clinical pathways and complete documentation with rigorous prospective study is necessary to improve and refine future guideline development.

Carcinoma, Squamous Cell↗
PubMed2004

Mitotic rate and younger age are predictors of sentinel lymph node positivity: lessons learned from the generation of a probabilistic model.

BACKGROUND: Sentinel lymph node (SLN) biopsy allows surgeons to identify patients with subclinical nodal involvement who may benefit from lymphadenectomy and, possibly, adjuvant therapy. Several factors have been variably, and sometimes discordantly, reported to have predictive value for SLN metastasis to best select which patients require SLN biopsy. METHODS: We reviewed 419 patients who underwent SLN biopsy for melanoma from a prospectively collected melanoma database. To derive a probabilistic model for the occurrence of a positive SLN, a multivariate logistic model was fit by using a stepwise variable selection method. The accuracy of each model was evaluated by using receiver operator characteristic curves. RESULTS: On univariate analysis, the number of mitoses per square millimeter, increasing Breslow depth, decreasing age, ulceration, and melanoma on the trunk showed a significant relationship to a positive SLN. Multivariate analysis revealed that once age, mitotic rate, and Breslow thickness were included, no other factor, including ulceration, was significantly associated with a positive SLN. The data suggest that younger patients with tumors <1 mm may still have a substantial risk for a positive SLN, especially if the mitotic rate is high. CONCLUSIONS: In addition to Breslow depth, mitoses per square millimeter and younger age were factors identified as independent predictors of a positive SLN. This model may identify patients with thin melanoma at sufficient risk for metastases to justify SLN biopsy.

Adult↗
PubMed2003

Sentinel lymph node biopsy for patients with problematic spitzoid melanocytic lesions: a report on 18 patients.

BACKGROUND: Spindle and/or epithelioid melanocytic proliferations that display overlapping histopathologic features of Spitz nevus and Spitz-like melanoma are diagnostically difficult and controversial melanocytic tumors. There are reports of such lesions metastasizing to regional lymph nodes, with a few widely disseminating, resulting in death. METHODS: The authors reviewed clinical and histopathologic data on all patients with atypical or borderline spitzoid melanocytic proliferations who underwent sentinel lymph node biopsy (SLNB). They examined how frequently histologically problematic or borderline spitzoid melanocytic lesions metastasized to sentinel lymph nodes (SLNs) and which clinical or histologic features, if any, predisposed patients to a higher risk lesion. RESULTS: Six male patients and 12 female patients, ages 5-32 years (mean, 16 years), had tumors ranging in size from 1.2 mm to 7.9 mm (mean, 3.5 mm) in thickness. Atypical histologic features that were present most frequently included incomplete maturation (18 of 18 patients), deep dermal mitoses (16 of 18 patients), nuclear pleomorphism (10 of 18 patients), and focal sheet-like growth (10 of 18 patients). Eight of 18 patients (44%) had SLN metastasis and were offered adjuvant treatment. One of eight patients with SLN positive results who underwent regional lymphadenectomy had one additional involved lymph node. All 18 patients were alive and well with no evidence of recurrent or metastatic disease after a follow-up of 3-42 months (mean, 12 months). CONCLUSIONS: Histologically atypical or borderline spitzoid, melanocytic tumors are diagnostically challenging and controversial melanocytic lesions, some of which represent unrecognized melanomas. SLNB aids in confirming a diagnosis of melanoma and identifies patients who may benefit from early therapeutic lymph node dissection and/or adjuvant therapy.

Adolescent↗
PubMed2003

Reliability of sentinel lymph node mapping with biopsy for head and neck cutaneous melanoma.

OBJECTIVES: To determine (1) the reliability of sentinel lymph node mapping with biopsy (SLNB) in head and neck cutaneous melanoma to accurately stage nodal basins and (2) the safety of SLNB in both the neck and parotid regions. DESIGN: Retrospective cohort study with a median follow-up of 25 months. All patients had a minimum follow-up of 1 year. SETTING: Academic medical center. PATIENTS: Eighty evaluable patients diagnosed as having head and neck cutaneous melanoma and staged using SLNB. INTERVENTIONS: Sentinel lymph nodes were identified using preoperative lymphoscintigraphy and a combination of intraoperative gamma probe and isosulfan blue dye. Patients with a SLN positive for melanoma underwent therapeutic lymphadenectomy followed by an evaluation for adjuvant therapies. Patients with a negative SLNB result were followed up clinically. MAIN OUTCOME MEASURES: Percentage of positive SLNs, regional recurrence in the setting of a negative SLNB result (false-negative rate), and procedure complications. RESULTS: The mean Breslow depth was 2.35 mm. A SLN was identified in 77 (96.3%) of cases, with an average of 2.18 nodes per patient. Of the sentinel nodes identified, 74% were from the neck region. The remaining 26% were from the parotid basin. No facial nerve complications occurred. Of the patients, 14 (18%) were SLN positive for metastatic melanoma. The regional failure rate in the setting of a negative SLNB result was 4.5%. CONCLUSIONS: Sentinel lymph node mapping with biopsy is a reliable technique to diagnose regional spread from head and neck cutaneous melanoma. This procedure can be performed in both neck and parotid nodal basins with safety and accuracy similar to non-head and neck sites.

Adolescent↗
PubMed2003

Vascular expression of matrix metalloproteinase-13 (collagenase-3) in basal cell carcinoma.

Matrix metalloproteinase-13 (MMP-13; collagenase-3) was detected in the vasculature from 17 of 20 human basal cell carcinomas as assessed by immunohistology immediately after surgery. In contrast, MMP-1 (interstitial collagenase) was detected in the vasculature of only two of the same specimens. MMP-13 reactivity was also observed in the capillaries of normal human skin taken from the wound margin. Human dermal microvascular endothelial cells as well as human umbilical vein endothelial cells were isolated in culture and examined for MMP-13 expression. By reverse transcription-polymerase chain reaction and Southern blotting, an MMP-13 transcript was detected in unstimulated endothelial cells. The transcript was upregulated in cells treated with 50 nM phorbol myristate acetate (PMA). Western blotting demonstrated the presence of an anti-MMP-13 - immunoreactive protein in culture fluid from both cell sources. Immunoreactivity was stronger in culture fluid from cells treated with interleukin-1alpha (IL-1alpha) than in culture fluid from control cells. Tumor necrosis factor-alpha (TNF-alpha) and PMA also upregulated MMP-13 expression but these agents were not as effective as IL-1alpha. Additionally, reactivity was greater in culture fluid from endothelial cells grown on three-dimensional lattices of polymerized type I collagen than on dried collagen films. These data indicate that endothelial cells in the skin are a source of MMP-13 and that enzyme expression is upregulated under conditions that promote endothelial cell growth and vascular differentiation.

Blotting, Southern↗
PubMed2003

Placental metastasis of maternal melanoma.

Metastasis of maternal malignant tumor to the products of conception is a rare event. Melanoma is the most common maternal malignant tumor to metastasize to the placenta and the fetus. We report the case of a 28-year-old woman with melanoma during pregnancy. At parturition, histologic evaluation of the placenta revealed metastatic melanoma, and multiple organ metastasis developed. The infant was free of disease. Metastasis to products of conception portends a poor prognosis for the mother. To our knowledge, this report is the first of a patient with melanoma metastasis to the placenta to survive more than 7 months after parturition. As caretakers of patients with melanoma, dermatologists are in a position to coordinate and direct the care and follow-up treatment of affected patients.

Adult↗
PubMed2002

Thin primary cutaneous melanomas: associated detection patterns, lesion characteristics, and patient characteristics.

BACKGROUND: Public awareness and education may lead to the detection of thinner melanomas, which may result in a decrease in morbidity and mortality rates. Which detection patterns, lesion, and patient characteristics are associated with early detection? METHODS: Using the University of Michigan prospective melanoma database, the detection patterns, lesion characteristics, and patient characteristics of 1515 consecutive patients with in situ or invasive cutaneous melanomas were reviewed. Tumor thickness (measured in millimeters) was evaluated in relationship to detection patterns (patient, physician, spouse), lesion characteristics (change in color, size, shape/elevation, ulceration, bleeding, tenderness, itching), and patient characteristics (gender, skin type, number of atypical and clinically benign nevi, history of sunburn, personal and family history of melanoma). RESULTS: Patient characteristics associated with early detection included female gender, at least one atypical nevus, greater than 20 clinically benign nevi, and/or a personal history of melanoma. Skin types I, II, and III, a history of sunburn, and/or a family history of melanoma were also associated with thinner lesions, but these associations were not statistically significant. Lesion characteristics associated with earlier detection included a change in color, size, shape/elevation, and/or itching. Physician-detected melanomas were significantly thinner than patient or spouse-detected lesions. CONCLUSIONS: Educational campaigns should include increasing melanoma awareness in males and educating the public on the early signs and symptoms. Education should be directed at both high and low-risk groups. Physicians should consider performing total skin examinations routinely on patients. Although they detect a relatively small percentage of all melanomas, physicians detect significantly thinner lesions.

Adult↗
PubMed2002

Melanoma information on the Internet: often incomplete--a public health opportunity?

PURPOSE: To assess the accuracy and completeness of information regarding melanoma on the Internet, retrieved by use of search engines. METHODS: The first 30 uniform/universal resource locators (URLs) from each of eight search engines using the search term "melanoma" were retrieved for evaluation of accuracy and completeness using a 35-point checklist rating system instrument. Four reviewers independently rated each of 35 sites, and one reviewer rated all 74 assessable sites. Kappa statistics were used to evaluate interrater variability. RESULTS: A total of 74 assessable Web sites were evaluated. The remainder were inaccessible, link pages only, or duplicates. Thirty-five Web sites were each independently rated by four reviewers. The remaining 39 Web sites were each rated by one reviewer. The mean kappa statistic for all variables and all rater pairs for which a kappa could be calculated was 0.824, indicating excellent overall inter-rater reliability. The majority of Web sites failed to include complete information on general information, risk factors, diagnosis, treatment, prevention, and prognosis. Ten Web sites (14%) contained a total of 13 inaccuracies, most relatively minor. CONCLUSION: Medical information retrieved with the search term melanoma was likely to lack complete basic melanoma information and contained inaccuracies in 14% of sites. Health care providers can help patients by recommending comprehensive and accurate Web sites for patient review, by working to create accurate and thorough Web-based health information material, and by educating patients and the public about the variability in completeness and accuracy.

Humans↗
PubMed2002

Conventional diamond fraise vs manual spot dermabrasion with drywall sanding screen for scars from skin cancer surgery.

OBJECTIVE: To directly compare cosmetic improvement and postoperative sequelae resulting from dermabrasion of surgical scars with conventional motor-powered diamond fraise vs manual dermabrasion with medium-grade drywall sanding screen. DESIGN: Patients were randomly assigned to receive treatment with conventional diamond fraise dermabrasion to one half of the scar and manual dermabrasion with a drywall sanding screen to the other half in a prospective, comparative clinical study. Blinded observers assessed clinical variables during a 6-month follow-up period. SETTING: University hospital/cancer center-based cutaneous surgery unit. PATIENTS: Twenty-one healthy volunteers, Fitzpatrick skin type I to III, with contour irregularities resulting from granulation (7 patients) or reconstruction (14 patients) after skin cancer excision. INTERVENTIONS: One half of the patient's scar was treated with motor-powered diamond fraise dermabrasion and the other half was treated with manual dermabrasion with medium-grade drywall sanding screen. MAIN OUTCOME MEASURES: Correction of contour, scarline visibility, time to reepithelialization, presence or absence of milia, degree of postoperative erythema, hypertrophic scarring, patients' subjective reports of postoperative pain, and presence of pigmentary changes were observed for both methods. Standardized scoring systems were used to quantify outcome measures. RESULTS: According to the standardized scoring systems, no differences were found between the 2 methods at any point. In addition, no significant differences were found between the methods for any measure at any of the time points. CONCLUSION: Both dermabrasion techniques are equally effective in improving the cosmetic appearance of surgical scars.

Adult↗
PubMed2002

Immunostaining for cytokeratin 20 improves detection of micrometastatic Merkel cell carcinoma in sentinel lymph nodes.

BACKGROUND: Sentinel lymph node biopsy (SLNBx) can identify Merkel cell carcinoma (MCC) micrometastasis. OBJECTIVE: We attempted to examine the effectiveness of immunostaining and identify antibodies most appropriate for evaluation of SLNBxs for MCC. METHODS: Histopathologic material from 10 patients with MCC who had SLNBx was reviewed. RESULTS: Twenty-three SLNBxs from 10 patients appeared tumor-free in routine hematoxylin-eosin (H&E)-stained sections. However, tumor cells were detected in immunostained sections from 5 (22%) of 23 SLNBxs in 4 (40%) of 10 patients. Immunostains with pancytokeratin (panCK), cytokeratin-20 (CK-20), neurofilament protein, and chromogranin A were used for all primary and SLNBx specimens. All 5 (100%) micrometastatic foci stained strongly for CK-20 and panCK. Background normal lymph node tissue also stained for panCK but not for CK-20. CONCLUSION: Examination of H&E sections alone is insufficient for excluding micrometastatic MCC in sentinel lymph nodes. We observed the greatest sensitivity and specificity with anti-CK-20 antibody in identifying micrometastatic MCC in sentinel lymph nodes.

Aged↗
PubMed2002

The Z-plasty transposition flap for reconstruction of the middle cheek.

BACKGROUND: Large defects of the middle cheek may prove difficult to repair. Too wide for primary closure, such defects pose challenging reconstructive options because there are no cosmetic unit boundaries in which to camouflage incision lines without resorting to widely undermined flaps. OBJECTIVE: This article summarizes our experience with the Z-plasty and double Z-plasty transposition flaps for reconstruction of the cheek. METHODS: The Z-plasty transposition flap was used immediately after Mohs micrographic surgery to repair 14 defects of the middle cheek caused by basal cell carcinoma (n = 12) or squamous cell carcinoma (n = 2). In all cases, primary closure of the defect would have resulted in excessively long scars, scars oriented perpendicular to relaxed skin tension lines, and/or free-margin distortion. In 4 of these cases, a double Z-plasty was used. RESULTS: The cosmetic and functional outcomes were judged from good to excellent by patient and surgeon. No cases of infection occurred. In one patient, minor superficial tip necrosis healed without incident. A "spit" subcutaneous suture at one flap tip of another patient left a small nodular scar, which was primarily excised and healed well. CONCLUSIONS: The Z-plasty and double Z-plasty transposition flaps offer excellent primary reconstructive modalities for the repair of geographically isolated defects of the cheek that are large or misoriented for primary side-to-side closure. The theoretical and practical geometric characteristics of the Z-plasty transposition require preparation and practice to achieve consistently satisfying results.

Basal Cell Carcinoma↗
PubMed2002

Getting patients to the right healthcare sources: from real-world questions to strategy hubs.

To address the growing problem of novices accessing incomplete and unreliable information on the Web, this paper begins by probing the nature of strategic knowledge known by expert healthcare searchers. The analysis reveals the existence of a strategy that is focused to a specific type of healthcare question. To investigate whether there exist other similar strategies, we conduct two pilot studies. The first leads to the development of a taxonomy for skin cancer questions based on real-world questions. This taxonomy has high inter-rater agreement when tested with new real-world questions. The second pilot helps to identify 6 strategies that are specific to question types in the taxonomy. We demonstrate how these strategies can be made available to a wide range of users through a prototypical system referred to as a Strategy Portal. In conclusion, we briefly describe our current and future research to test if such a system can make patients more effective and efficient in the retrieval of reliable and relevant healthcare information on the Web.

Delivery of Health Care↗