Citations

We have identified 25 lesions involving alveolar lung parenchyma characterized by nodular proliferation of bland bilayered bronchiolar-type epithelium containing a continuous layer of basal cells. These lesions shared some histologic features with the recently described entity of ciliated muconodular papillary tumor (CMPT); however, the majority did not fit all diagnostic criteria in that they exhibited only focal or absent papillary architecture, and they had variable number of ciliated and mucinous cells, with some lesions entirely lacking 1 or both of these components. The morphologic and immunohistochemical features ranged from those resembling proximal bronchioles (proximal-type: moderate to abundant mucinous and ciliated cells; negative or weak TTF1 in luminal cells; n=8) to those resembling respiratory bronchioles (distal-type: scant or absent mucinous and ciliated cells; positive TTF1 in luminal cells; n=17). The hallmark of all lesions was a continuous layer of basal cells (p40 and CK5/6-positive). We provisionally designated these lesions as bronchiolar adenomas (BAs) and analyzed their clinicopathologic and molecular features. All BAs were discrete, sharply circumscribed lesions with a median size of 0.5 cm (range, 0.2 to 2.0 cm). Most lesions were either entirely flat (n=14) or contained focal papillary architecture (n=7); only 4 lesions, all proximal-type, were predominantly papillary, fitting the classic description of CMPT. Notably, of 9 lesions submitted for frozen section evaluation, 7 were diagnosed as adenocarcinoma. No postsurgical recurrences were observed for any lesions (median follow-up, 11 mo). Twenty-one BAs underwent next-generation sequencing and/or immunohistochemistry for BRAF V600E, revealing mutation profiles similar to those previously described for CMPTs, including BRAF V600E mutations (n=8, 38%), unusual EGFR exon 19 deletions (n=2, 10%), EGFR exon 20 insertions (n=2, 10%), KRAS mutations (n=5, 24%), and HRAS mutations (n=1, 5%). The mutation profiles were similar in proximal-type and distal-type lesions. In conclusion, we describe a family of putatively benign clonal proliferations with a spectrum of morphology recapitulating various levels of the bronchiolar tree, of which only a minor subset fits the classic description of CMPT. Comparable mutation profiles and partially overlapping morphologic features across the spectrum of these lesions support their nosological relationship. We propose designating this entire family of lesions as BAs, and that lesions currently designated CMPTs represent a subgroup of this family.

Purpose The American Society of Clinical Oncology (ASCO) has a policy and set of procedures for endorsing recent clinical practice guidelines that have been developed by other professional organizations. Methods The Cancer Care Ontario (CCO) Guideline on Follow-up Care, Surveillance Protocol, and Secondary Prevention Measures for Survivors of Colorectal Cancer was reviewed by ASCO for methodologic rigor and considered for endorsement. Results The ASCO Panel concurred with the CCO recommendations and recommended endorsement, with the addition of several qualifying statements. Conclusion Surveillance should be guided by presumed risk of recurrence and functional status of the patient (important within the first 2 to 4 years). Medical history, physical examination, and carcinoembryonic antigen testing should be performed every 3 to 6 months for 5 years. Patients at higher risk of recurrence should be considered for testing in the more frequent end of the range. A computed tomography scan (abdominal and chest) is recommended annually for 3 years, in most cases. Positron emission tomography scans should not be used for surveillance outside of a clinical trial. A surveillance colonoscopy should be performed 1 year after the initial surgery and then every 5 years, dictated by the findings of the previous one. If a colonoscopy was not preformed before diagnosis, it should be done after completion of adjuvant therapy (before 1 year). Secondary prevention (maintaining a healthy body weight and active lifestyle) is recommended. If a patient is not a candidate for surgery or systemic therapy because of severe comorbid conditions, surveillance tests should not be performed. A treatment plan from the specialist should have clear directions on appropriate follow-up by a nonspecialist.