Arch Pathol Lab Med. 2013 Dec;137(12):1792-7. doi: 10.5858/arpa.2012-0613-SA.

In compressed lung tissue microscopic sections of adenocarcinoma in situ may mimic papillary adenocarcinoma.

Thunnissen E, Beliën JA, Kerr KM, Chung JH, Flieder DB, Noguchi M, Yatabe Y, Hwang DM, Lely RJ, Hartemink KJ, Meijer-Jorna LB, Tsao MS.

Source

From the Departments of Pathology (Drs Thunnissen and Beliën), Radiology (Dr Lely), and Surgery (Dr Hartemink), VU University Medical Center, Amsterdam, the Netherlands; the Department of Pathology, Aberdeen Royal Infirmary, Aberdeen University Medical School, Aberdeen, Scotland (Dr Kerr); the Department of Pathology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea (Dr Chung); the Department of Pathology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (Dr Flieder); the Department of Pathology, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Japan (Dr Noguchi); the Department of Pathology andMolecular Diagnostics, Aichi Cancer Center, Nagoya, Japan (Dr Yatabe); the Department of Pathology, University Health Network-Princess Margaret Hospital and University of Toronto, Toronto, Ontario, Canada (Drs Hwang and Tsao); and the Department of Pathology, Symbiant/Medical Center Alkmaar, Alkmaar, the Netherlands (Dr Meijer-Jorna).

Abstract

Context.-Surgical removal and pathologic handling of lung tissue has a compressive effect upon its architecture. The effect of surgical atelectasis on morphology has not been examined in depth, especially with respect to lung adenocarcinomas. 

Objective.-To examine the influence of surgical atelectasis on morphologic lepidic growth pattern, mimicking papillary adenocarcinoma pattern. 

Design.-In 2 cases serial sections of resected pulmonary adenocarcinoma were used, as was a 3-dimensional reconstruction. Elastin stains were performed on primary and metastatic adenocarcinomas. 

Results.-Perfusion fixation of another case showed marked morphologic differences of less compressed peripheral lung tissue, emphasizing the preexisting alveolar structure. An elastic stain may help identify true lesional architecture. 

Conclusions.-We demonstrate that microscopic sections of adenocarcinoma in situ in compressed/collapsed tissue may give rise to a pseudopapillary pattern mimicking invasive adenocarcinoma. Accurate appreciation of different tumor architecture in lung adenocarcinoma has important biologic and clinical implications. Pathologists should be aware of the possibility of misclassification of adenocarcinoma pattern due to tissue artifacts caused by lung tissue handling.