The American journal of surgical pathology
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Am. J. Surg. Pathol. · Dec 2014
Activating BRAF V600E mutation in aggressive pediatric Langerhans cell histiocytosis: demonstration by allele-specific PCR/direct sequencing and immunohistochemistry.
Langerhans cell histiocytosis (LCH) is a rare neoplastic disease originating from cells characterized by antigen-presenting Langerhans cell phenotype. The clinical spectrum of LCH is highly variable including localized and disseminated forms mostly occurring in children. Recently, about 60% of LCHs were reported to carry the activating BRAF mutation V600E. ⋯ Wild-type BRAF cases (7/15, 46.6%) with generally comparable initial presentation were all treated successfully. In conclusion, activating V600E BRAF mutation can be frequently demonstrated in pediatric LCH by both allele-specific PCR and IHC. Unfavorable risk cases potentially also responding to BRAF-inhibitory therapy can be identified by mutation testing using archival formaldehyde-fixed, paraffin-embedded tumor samples.
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Am. J. Surg. Pathol. · Dec 2014
Surgical resection margins in desmoid-type fibromatosis: a critical reassessment.
The prognostic value of surgical resection margins in predicting recurrence of desmoid-type fibromatosis remains inconclusive, and appropriate resection margins are not defined. We analyzed whether specific factors related to margin status, including the adequacy of pathologic assessment, affect the prognostic impact of surgical resection margins in a retrospective cohort study. The distance (clearance) and tissue composition of resection margins were recorded for primary desmoid resections with negative margins. ⋯ Surgical resection margin status, as currently evaluated and reported, fails to predict recurrence-free survival for desmoid tumors. Instead, positive or close (<1 mm) resection margins are predictive of disease recurrence. In addition, multiple targeted sections are necessary for accurate assessment of surgical resection margins of desmoid-type fibromatosis.