Evaluation of the clonality of multilobar bronchioloalveolar carcinoma of the lung: case report

Invasive Mucinous Adenocarcinomas With Spatially Separate Lung Lesions: Analysis of Clonal Relationship by Comparative Molecular Profiling

INTRODUCTION

Pulmonary invasive mucinous adenocarcinomas (IMAs) often present with spatially separate lung lesions. Clonal relationship between such lesions, particularly those involving contralateral lobes, is not well established. Here, we used comparative genomic profiling to address this question.

METHODS

Patients with genomic analysis performed on two IMAs located in different lung regions were identified. Molecular assays included DNA-based next-generation sequencing (NGS) for 410 to 468 genes (Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets), RNA-based NGS for 62 genes (Memorial Sloan Kettering-Fusion), or non-NGS assays.

RESULTS

Comparative genomic profiling was performed on two separate IMAs in 24 patients, of whom 19 had contralateral lesions. Tumors from all but one patient shared matching driver alterations, including KRAS (n = 19), NRG1 (n = 2), ERBB2 (n = 1) or BRAF (n = 1). In addition, in patients with paired tumors profiled by NGS (n = 12), shared driver alterations were accompanied by up to 4 (average 2.6) other identical mutations, further supporting the clonal relationship between the tumors. Only in a single patient separate IMAs harbored entirely nonoverlapping mutation profiles, supporting clonally unrelated, distinct primary tumors. Notably, in a subset of patients (n = 3), molecular testing confirmed a clonal relationship between the original resected IMAs and subsequent contralateral IMA presenting after an extremely long latency (8.1-11.7 y).

CONCLUSIONS

Comparative molecular profiling supports that nearly all separate pulmonary IMA lesions represent intrapulmonary spread arising from a single tumor and documents a subset with a remarkably protracted course of intrapulmonary progression. This study reinforces the unique biology and clinical behavior of IMAs while further highlighting the value of genomic testing for clarifying the clonal relationship between multiple lung carcinomas.

The IASLC Lung Cancer Staging Project: Background Data and Proposals for the Application of TNM Staging Rules to Lung Cancer Presenting as Multiple Nodules with Ground Glass or Lepidic Features or a Pneumonic Type of Involvement in the Forthcoming Eighth Edition of the TNM Classification

INTRODUCTION

Application of tumor, node, and metastasis (TNM) classification is difficult in patients with lung cancer presenting as multiple ground glass nodules or with diffuse pneumonic-type involvement. Clarification of how to do this is needed for the forthcoming eighth edition of TNM classification.

METHODS

A subcommittee of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee conducted a systematic literature review to build an evidence base regarding such tumors. An iterative process that included an extended workgroup was used to develop proposals for TNM classification.

RESULTS

Patients with multiple tumors with a prominent ground glass component on imaging or lepidic component on microscopy are being seen with increasing frequency. These tumors are associated with good survival after resection and a decreased propensity for nodal and extrathoracic metastases. Diffuse pneumonic-type involvement in the lung is associated with a worse prognosis, but also with a decreased propensity for nodal and distant metastases.

CONCLUSION

For multifocal ground glass/lepidic tumors, we propose that the T category be determined by the highest T lesion, with either the number of tumors or m in parentheses to denote the multifocal nature, and that a single N and M category be used for all the lesions collectively-for example, T1a(3)N0M0 or T1b(m)N0M0. For diffuse pneumonic-type lung cancer we propose that the T category be designated by size (or T3) if in one lobe, as T4 if involving an ipsilateral different lobe, or as M1a if contralateral and that a single N and M category be used for all pulmonary areas of involvement.

Predictive CT findings of malignancy in ground-glass nodules on thin-section chest CT: the effects on radiologist performance

Our purpose was to identify thin-section chest computed tomography (CT) findings of malignancy other than the presence of a solid portion within ground-glass nodules (GGNs) and to evaluate whether the radiologists' performance in determining malignancy can be enhanced with this information. The predictive CT findings of malignancy extracted from the CT findings of 80 GGNs (47 malignant, 33 benign) were a size of >8 mm [odds ratio (OR), 10.930; P = 0.045] and a lobulated border (OR, 13.769; P = 0.016) for pure GGNs and a lobulated border (OR, 10.200; P = 0.024) for mixed GGNs. Four chest radiologists and five radiology residents participated in the observer performance study with CT of 130 GGNs (67 malignant, 63 benign). Receiver-operating characteristic (ROC) analysis was used to compare radiologists' performances before and after providing these predictive findings. For pure GGNs, mean areas under the curve (A(z)) of all readers without and with CT predictive information were significantly different (0.621 +/- 0.052 and 0.766 +/- 0.055, P < 0.05). For mixed GGNs, the A(z) values achieved without and with predictive information were not significantly different (0.727 +/- 0.064 and 0.764 +/- 0.056, P > 0.05). Information about lesion size and morphological characteristics can enhance radiologists' performance in determining malignancy of pure GGNs.

Clinical, pathological and thin-section CT features of persistent multiple ground-glass opacity nodules: comparison with solitary ground-glass opacity nodule

PURPOSE

To retrospectively compare the clinical, pathological, and thin-section CT features of persistent multiple ground-glass opacity (GGO) nodules with those of solitary GGO nodules.

MATERIALS AND METHODS

Histopathologic specimens were obtained from 193 GGO nodules in 136 patients (87 women, 49 men; mean age, 57; age range 33-81). The clinical data, pathologic findings, and thin-section CT features of multiple and solitary GGO nodules were compared by using t-test or Fisher's exact test.

RESULTS

Multiple GGO nodules (n=105) included atypical adenomatous hyperplasia (AAH) (n=31), bronchioloalveolar carcinoma (BAC) (n=33), adenocarcinoma (n=34) and focal interstitial fibrosis (n=7). Solitary GGO nodules included AAH (n=8), BAC (n=15), adenocarcinoma (n=55) and focal interstitial fibrosis (n=10). AAH (P=.001) and BAC (P=.029) were more frequent in multiple GGO nodules, whereas adenocarcinoma (P<.001) was more frequent in solitary GGO nodules. Female sex (P<.001), nonsmoker (P=.012) and multiple primary lung cancers (P<.001) were more frequent for multiple GGO nodules, which were smaller (12 mm+/-7.9) than solitary GGO nodules (17 mm+/-8.1) (P<.001). Air-bronchogram (P=.019), bubble-lucency (P=.004), and pleural retraction (P<.001) were more frequent in solitary GGO nodules. There was no postoperative recurrence except for one patient with multiple GGO nodules and one with solitary GGO nodule.

CONCLUSION

Clinical, pathological, and thin-section CT features of persistent multiple GGO nodules were found to differ from those of solitary GGO nodules. Nevertheless, the two nodule types can probably be followed up and managed in a similar manner because their prognoses were found to be similar.

Persistent Pulmonary Nodular Ground-Glass Opacity at Thin-Section CT: Histopathologic Comparisons

PURPOSE

To retrospectively compare pure pulmonary ground-glass opacity (GGO) nodules observed on thin-section computed tomography (CT) images with histopathologic findings.

MATERIALS AND METHODS

The institutional review board approved this study and waived informed consent. Histopathologic specimens were obtained from 53 GGO nodules in 49 patients. CT scans were assessed in terms of nodule size, shape, contour, internal characteristics, and the presence of a pleural tag. The findings obtained were compared with histopathologic results. Differences in thin-section CT findings according to histopathologic diagnoses were analyzed by using the Kruskal-Wallis test or Fisher exact test.

RESULTS

Of 53 nodules in 49 patients (20 men, 29 women; mean age, 54 years; range, 29-78 years), 40 (75%) proved to be broncholoalveolar cell carcinoma (BAC) (n=36) or adenocarcinoma with predominant BAC component (n=4), three (6%) atypical adenomatous hyperplasia, and 10 (19%) nonspecific fibrosis or organizing pneumonia. No significant differences in morphologic findings on thin-section CT scans were found among the three diseases (all P>0.05). A polygonal shape (25%, 10 of 40 nodules) and a lobulated or spiculated margin (45%, 18 of 40) in BAC or adenocarcinoma with predominant BAC component were caused by interstitial fibrosis or infiltrative tumor growth. A polygonal shape and a lobulated or spiculated margin were observed in two (20%) and three (30%) of 10 nodules, respectively, in organizing pneumonia/fibrosis were caused by granulation tissue aligned in a linear manner in perilobular regions with or without interlobular septal thickening.

CONCLUSION

About 75% of persistent pulmonary GGO nodules are attributed to BAC or adenocarcinoma with predominant BAC component, and at thin-section CT, these nodules do not manifest morphologic features that distinguish them from other GGO nodules with different histopathologic diagnoses.