Merkel cell carcinoma arising in a patient with a history of multiple malignancies.

Merkel cell carcinoma (MCC) is a rare and highly aggressive neuroendocrine carcinoma of the skin. Although the association between MCC and other primary malignancies has been documented, the mechanism of this association has not been elucidated. We report a case of MCC in a man with a history of multiple primary malignancies and treatment with immunomodulators. This case highlights the increased incidence of other malignancies in patients with MCC and is unique given the number and diversity of primary malignancies found in this patient.

Discordance in the histopathologic diagnosis of difficult melanocytic neoplasms in the clinical setting.

BACKGROUND: The gold standard for diagnosing melanocytic neoplasms is by histopathologic examination. However, lack of agreement among expert dermatopathologists in evaluating these tumors has been well established in experimental settings. OBJECTIVE: This study examines the discordance among dermatopathologists in evaluating difficult melanocytic neoplasms in a clinical setting where the diagnosis impacts patient management. METHODS: Retrospective review of consultation reports over a 6-year period. RESULTS: There was complete agreement among the consultants in 54.5% of the cases. However, a high level of disagreement was found in 25% of the cases. LIMITATIONS: The analysis was limited to two consultant dermatopathologists. CONCLUSIONS: There are limitations to the practical applications of histologic criteria for diagnosing difficult melanocytic tumors. It is not malpractice for a pathologist to have rendered a diagnosis that did not predict clinical outcome as long as 'standard of care' has been followed in his/her evaluation of the specimen.

Severe aphthous stomatitis associated with oral calcineurin and mTOR inhibitors.

BACKGROUND: Aphthous stomatitis, a common mucocutaneous disorder, is a well accepted complication of sirolimus therapy. This association has been reported less frequently with tacrolimus. CASE: We present an 11-year old male with Budd-Chiari syndrome who experienced profound worsening of chronic aphthous ulcers after immunosuppressive therapy was changed from tacrolimus to sirolimus. CONCLUSION: Since these drugs are used widely in the pediatric transplantation population, this report serves to heighten awareness of this debilitating phenomenon, and to stress the importance of exercising caution when sirolimus and tacrolimus are administered in combination to pediatric patients.

Kaposi's sarcoma resolves after sirolimus therapy in a patient with pemphigus vulgaris.

BACKGROUND: Iatrogenic Kaposi's sarcoma (KS) has been reported in patients who use immunosuppressive regimens for the treatment of autoimmune disorders, malignant neoplasms, and organ transplant rejection. However, iatrogenic KS in the setting of pemphigus vulgaris (PV) has been infrequently observed. The conventional treatment strategy for iatrogenic KS has focused on reducing immunosuppression, which carries a poor prognosis owing to a substantial risk for exacerbation of the primary disease. OBSERVATIONS: A 49-year-old man developed KS on his wrist after 2 years of long-term immunosuppressive therapy with prednisone, methotrexate, and dapsone for well-controlled PV. Three months after the substitution of methotrexate with sirolimus, the KS gradually resolved. With the patient on a maintenance regimen of sirolimus, in conjunction with low-dose prednisone and dapsone therapy, KS and PV have remained in remission, without further recurrence, during a 24-month follow-up period. CONCLUSION: The present case introduces a novel therapy for this patient population, highlighting the efficacy of sirolimus in treating iatrogenic KS without sacrificing the immunosuppression necessary to maintain control of PV.

Polymorphic cytochrome P450 enzymes and post-marketing drug dosage revisions: clinical relevance to dermatologic therapies.

The therapeutic drug resources available to dermatologists have expanded and encompass off-label use of other drugs as well. As these new resources are employed, it is important to remain vigilant of possible drug interactions and toxicities contingent upon inter-individual variability of plasma drug levels. This article reviews the biochemistry of CYP enzymes and the clinical implications of genetic polymorphisms as relating to certain dermatologic drugs. In addition, we discuss the potential clinical function of cutaneous CYP enzymes.