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.
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Am. J. Surg. Pathol. · Nov 2014
Comparative StudyAssessment of tumor regression of esophageal adenocarcinomas after neoadjuvant chemotherapy: comparison of 2 commonly used scoring approaches.
Histopathologic determination of tumor regression provides important prognostic information for locally advanced gastroesophageal carcinomas after neoadjuvant treatment. Regression grading systems mostly refer to the amount of therapy-induced fibrosis in relation to residual tumor or the estimated percentage of residual tumor in relation to the former tumor site. Although these methods are generally accepted, currently there is no common standard for reporting tumor regression in gastroesophageal cancers. ⋯ Modification into simplified 3-tiered systems showed comparable interobserver agreement but better prognostic stratification for both systems (log rank Becker: P=0.015; Mandard P=0.03), with independent prognostic impact for overall survival (modified Becker: P=0.011, hazard ratio=3.07; modified Mandard: P=0.023, hazard ratio=2.72). In conclusion, both systems provide substantial to excellent interobserver agreement for estimation of tumor regression after neoadjuvant chemotherapy in esophageal adenocarcinomas. A simple 3-tiered system with the estimation of residual tumor in % (complete regression/1% to 50% residual tumor/>50% residual tumor) maintains the highest reproducibility and prognostic value.
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Am. J. Surg. Pathol. · Nov 2014
Case ReportsProtuberant fibro-osseous lesions of the temporal bone: two additional case reports.
The most commonly encountered fibro-osseous lesions of the skull bone are fibrous dysplasia and ossifying fibroma. Two cases of a unique "protuberant fibro-osseous lesion of the temporal bone" were first described by Selesnick and colleagues in 1999, and 2 further cases were reported in 2010 under the name "Bullough lesion". We recently found 2 new cases of this rare entity. ⋯ The location, histology, and clinical course of these 2 cases were identical to the 4 cases previously reported, although age and sex varied. The lesions were tested for the R201H mutation in the GNAS gene, which is present in fibrous dysplasia. No mutations were found, suggesting a different genetic background for these lesions.
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Am. J. Surg. Pathol. · Sep 2014
Comparative StudyMorphologic and molecular characterization of traditional serrated adenomas of the distal colon and rectum.
Of the serrated polyps, the origin, morphologic features, molecular alterations, and natural history of traditional serrated adenomas (TSAs) are the least understood. Recent studies suggest that these polyps may arise from precursor lesions. The frequencies of KRAS and BRAF mutations vary between these studies, and only 1 small study has measured CpG island methylation using current markers of methylation. ⋯ Unlike sessile serrated adenomas/polyps, TSAs rarely had diffuse expression of ANXA10. Importantly, BRAF-mutated TSAs had more widespread methylation of a 5-marker CpG island panel compared with KRAS-mutated polyps. However, ectopic crypt foci, a proposed defining feature of TSA, were not associated with any specific molecular alteration.