![]() |
Case Report
1 MD, Department of Pathology, Mercy Medical Center, Springfield, MA, USA
2 PA (ASCP), Department of Pathology, Mercy Medical Center, Springfield, MA, USA
3 MD, Department of Thoracic Surgery, Mercy Medical Center, Springfield, MA, USA
Address correspondence to:
Sandy Liu
Mercy Medical Center, 271 Carew Street, Springfield, MA,
USA
Message to Corresponding Author
Article ID: 100080Z11SL2024
Introduction: Carcinoid tumorlets are usually incidental findings in lung excisions. These neuroendocrine proliferations should be less than 5 mm, and resemble typical carcinoid (TC) lacking necrosis and elevated mitotic activity. We report a case of atypical carcinoid (AC) presenting as multiple tumors all measuring less than 5 mm, mimicking carcinoid tumorlets.
Case Report: Our patient underwent a right upper lobectomy for multifocal invasive lepidic adenocarcinoma. Multiple nodules of neuroendocrine cells less than 5 mm in greatest dimension were noted within the lobectomy. Unlike carcinoid tumorlets, these nodules showed >2 mitotic figures per square millimeter and punctate necrosis. The ACs masqueraded as multiple microscopic tumor foci (<5 mm) resembling “carcinoid tumorlets” in adjacent background lung tissue next to the adenocarcinoma. However, increased mitoses and punctate necrosis were diagnostic of AC. A background of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) was noted, appeared to be a precursor lesion to AC, and demonstrated the DIPNECH’s preneoplastic potential to evolve directly into an AC.
Conclusion: The rare possibility of AC in “tumorlet”-appearing multiple micronodules should be considered in presence of elevated mitotic activity and necrosis in background of DIPNECH.
Keywords: Atypical carcinoid, DIPNECH, Tumorlets
Sandy Liu - Conception of the work, Design of the work, Acquisition of data, Analysis of data, Drafting the work, Revising the work critically for important intellectual content, Final approval of the version to be published, Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Amy Lynn - Conception of the work, Design of the work, Acquisition of data, Analysis of data, Drafting the work, Revising the work critically for important intellectual content, Final approval of the version to be published, Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Dianne Grunes - Conception of the work, Design of the work, Acquisition of data, Analysis of data, Drafting the work, Revising the work critically for important intellectual content, Final approval of the version to be published, Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Jamie Drake - Acquisition of data, Analysis of data, Revising the work critically for important intellectual content, Final approval of the version to be published, Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Laki Rousou - Conception of the work, Design of the work, Acquisition of data, Analysis of data, Drafting the work, Revising the work critically for important intellectual content, Final approval of the version to be published, Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Guarantor of SubmissionThe corresponding author is the guarantor of submission.
Source of SupportNone
Consent StatementWritten informed consent was obtained from the patient for publication of this article.
Data AvailabilityAll relevant data are within the paper and its Supporting Information files.
Conflict of InterestAuthors declare no conflict of interest.
Copyright© 2024 Sandy Liu et al. This article is distributed under the terms of Creative Commons Attribution License which permits unrestricted use, distribution and reproduction in any medium provided the original author(s) and original publisher are properly credited. Please see the copyright policy on the journal website for more information.