%0 Journal Article %A LUKAS SOLLFRANK %A SEBASTIAN LETTMAIER %A MICHAEL ERDMANN %A UGUR USLU %T Panniculitis Under Successful Targeted Inhibition of the MAPK/ERK Signaling Pathway in a Patient With BRAF V600E-mutated Spindle Cell Oncocytoma of the Pituitary Gland %D 2019 %R 10.21873/anticanres.13549 %J Anticancer Research %P 3955-3959 %V 39 %N 7 %X Background: Spindle cell oncocytoma (SCO) is a rare non-neuroendocrine neoplasm of the pituitary gland. In general, surgical excision and radiation therapy is performed. However, local recurrences are frequently seen, requiring repeated surgical and radio-oncological interventions. Thus, mutational analysis of the tumor and targeted therapy may represent a valuable therapy option in these patients. Case Report: A 38-year-old female patient with past medical history of 6 surgeries (two transsphenoidal and four transcranial), radiation therapy, and chemoradiation therapy due to several recurrences of a SCO, presented for follow-up imaging. MRI of the brain showed growth of a tumor in the right parasellar region consistent with a new local recurrence, which due to its size and location was considered to be not resectable. Molecular analysis of a previously surgically removed tumor showed a BRAF V600E mutation and thus, combined targeted inhibition of the MAPK/ERK signaling pathway using a BRAF inhibitor and a MEK inhibitor was started. Due to drug-induced panniculitis, MEK inhibitor had to be stopped and BRAF inhibitor only was continued, which was well tolerated by the patient. Subsequent imaging revealed tumor regression already four weeks after therapy initiation and no disease progression has been observed to date. Conclusion: A SCO patient with BRAF V600E mutation was successfully treated using targeted inhibition of the MAPK/ERK signaling pathway. Under therapy, tumor regression was observed and the patient has been free of progressive disease for more than two years now. Thus, mutational analysis and targeted inhibition may offer an effective treatment option for SCO patients, while potential side-effects to this therapy, like observed in our case, can occur and needs to be adequately treated. %U https://ar.iiarjournals.org/content/anticanres/39/7/3955.full.pdf