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June 2019
A 60-year-old male with a basilar lung mass
Contributors:
Rumeal D. Whaley, MD
PGY-3 Resident Physician, Anatomic Pathology and Clinical Pathology
Indiana University School of Medicine
Jingmei Lin, MD, PhD
Associate Professor
Department of Pathology & Laboratory Medicine
Indiana University School of Medicine
Clinical history: The patient was a 60-year-old white male with a long history of smoking and a slow growing lung mass. Prior surgery included coronary artery bypass grafting. The lung mass had a very slow interval growth over the last six to eight years. Most recent CT (Image 1) revealed a 5.5 x 2.5 cm mass-like opacity in the left lower lobe. This mass was in contact with a trace left pleural effusion and pleural thickening. There was distortion of adjacent bronchovascular bundles. Additionally present were multiple stable bilateral pulmonary nodules measuring up to 4 mm. No enlarged hilar, mediastinal, supraclavicular, or axillary lymph nodes were identified. A CT-guided biopsy was performed (at an outside facility) and revealed “fairly typical lung parenchyma which shows no significant inflammation, granulomata or malignancy.” There was concern this could represent a sampling error and it was decided to proceed to lobectomy. Intraoperatively, it was noted that there were extensive intrapleural adhesions.
Gross examination:The specimen comprised of a 12.5 x 9.5 x 6.1 cm portion of lung lobe. The pleural surface was purple-tan and smooth to roughen. Sectioning revealed a 3.5 x 3.2 x 0.7 cm firm tan indurated area.
Microscopic examination and immunohistochemistry: Histological examination of the lung mass revealed atelectatic lung parenchyma adjacent to fibrotic and thickened pleura (Fig. 1A). The pleura permeated into the lung parenchyma pulling adipose tissue along with it (Fig. 1A, 1B). Large caliber airways and vascular were pulled into close proximity in a vaguely whorled pattern (Fig 1A, 1C). The fibrotic plaque contained essentially no inflammation. Additionally present was a single focus of osseus metaplasia. No asbestos bodies were appreciated. In order to further evaluate the mass special stain for elastin was performed which showed the pleura plunging into the lung and whirling the lung parenchyma (Image 3). The immunohistochemical stain for AE1/AE3 highlighted the collapsed alveoli and respiratory epithelium (Image 4). While not necessary for the diagnosis, it does allow for an unobstructed view of the distorted architecture (large airways and vasculature pulled into close proximity).
Image 1: CT showing a well-defined mass abutting the vertebra
For PC users, right click to open image in a new window, then zoom to enlarge.
Fig. 1: A: Whole slide H&E. B: Atelectasis with adjacent adipose tissue (100x). C: Large caliber vessels within lung parenchyma (100x).
Fig. 1: A: Whole slide H&E. B: Atelectasis with adjacent adipose tissue (100x). C: Large caliber vessels within lung parenchyma (100x).
Image 2: Whole slide elastin stain showing pleura plunging into the lung and whirling the lung parenchyma
Image 3: Whole slide elastin stain showing pleura plunging into the lung and whirling the lung parenchyma
Fig 3: Whole slide AE1/AE3 highlighting collapsed alveoli and the distorted architecture.
Fig.3: Whole slide AE1/AE3 highlighting
collapsed alveoli and the distorted architecture.