CT features of lung metastases from pancreatic adenocarcinoma: Correlation with histopathologic findings

Pulmonary metastases from malignant melanoma showing ground-glass opacity nodules

PURPOSE

To investigate the frequency and characteristics of pulmonary metastases from malignant melanoma presenting as ground-glass opacity nodules (GGNs) on chest computed tomography (CT).

MATERIAL AND METHODS

A total of 354 patients with malignant melanoma who underwent chest CT for staging or follow-up were selected. We reviewed the CT images and enrolled 87 patients with lung metastases. Two radiologists evaluated the nodularity of the lung metastases (solid nodules or GGNs). Additionally, the tumor doubling time and disease type (mucosal, cutaneous, or acral melanomas) were analyzed.

RESULTS

GGNs were observed in 13 of 87 (14.9%) patients. The tumor doubling time was 52.0 ± 33.5 days (range: 10.9-111 days) for GGNs and 43.8 ± 27.5 days (range: 9.4-115.3 days) for solid nodules. GGNs changed to solid nodules in 54.5% of patients with increased GGN metastasis. More patients in the GGN group (patients whose metastases included GGNs) had mucosal melanomas than acral melanomas (p = 0.0478); however, no significant difference was observed in the frequency of mucosal and cutaneous melanomas (p = 0.0670). Similarly, the proportion of patients in the GGN-dominant pattern group (patients with GGNs only or more GGNs than solid nodules) who had mucosal melanomas was more than that of patients with acral and cutaneous melanomas (mucosal melanoma vs. acral melanoma, p = 0.0342; mucosal melanoma vs. cutaneous melanoma, p = 0.0344).

CONCLUSIONS

Lung metastases from malignant melanoma sometimes appear as GGNs on CT, with a frequency of 14.9% in this study. If lung metastasis is observed as a GGN, the tumor doubling time may be useful for differentiating lung metastasis of malignant melanoma from lung adenocarcinoma.

Pulmonary metastases from pancreatic cancer have different clinico-radiological features compared with those from colorectal cancer

BACKGROUND

Although pulmonary metastasectomy is a commonly-performed procedure, data are lacking on the feasibility and oncological efficacy of removal of pulmonary metastases from pancreatic cancer. In this study, we retrospectively compared features of pulmonary metastases from pancreatic cancer versus colorectal cancer (CRC, patients with CRC being common candidates for pulmonary metastasectomy) and outcomes of removing such metastases, with our aim being to identify specific features of the former.

METHODS

Data on removal of 182 pulmonary metastases (29 from pancreatic and 153 from CRC) performed from January 2013 to April 2024 were included in this analysis. Radio-pathological findings were compared between these groups. The study cohort comprised 139 pulmonary metastasectomies in 119 patients (24 with pancreatic cancer and 95 with CRC) in whom R0 resection was achieved and follow-up data were available.

RESULTS

Atypical radiological findings of pulmonary metastases, including polygonal-shape (P < 0.001), spiculae (P < 0.001), air bronchogram (P = 0.012), peripheral ground-glass opacities (P < 0.001), and pleural tags (P < 0.001) were present more frequently in metastases from pancreatic cancer than from CRC. Furthermore, pleural lavage cytology was more frequently positive in pulmonary metastases from pancreatic cancer than in those from CRC (P < 0.001). Disease-free survival was significantly shorter after the removal of metastases from pancreatic than from CRC (P < 0.001).

CONCLUSIONS

Some pulmonary metastases from pancreatic cancer have atypical radiological features. Surgical interventions for these may enable diagnosis. The prognosis is significantly poorer after removing metastases from pancreatic cancer than from CRC. The therapeutic significance of our findings requires further investigation.

Head-to-head comparison of 68 Ga-FAPI-46 PET/CT, 18F-FDG PET/CT, and contrast-enhanced CT for the detection of various tumors

OBJECTIVE

FAPI-PET/CT exhibits high tumor uptake and low background accumulation, enabling high-sensitivity tumor detection. We compared the diagnostic performance of 68 Ga-FAPI-46 PET/CT plus contrast-enhanced CT (CE-CT), 18F-FDG PET/CT plus CE-CT, and standalone CE-CT in patients with various malignancies.

METHODS

232 patients underwent 68 Ga-FAPI-46 PET/CT,18F-FDG PET/CT, and CE-CT each within 4 weeks. Detection rates were assessed by a blinded reader, with ≥ 2 weeks between scans of the same patient to avoid recall bias. A sub-analysis of diagnostic performance was performed for 490 histopathologically validated lesions. Detection rates were compared using McNemar's test.

RESULTS

Lesion-based detection rates in 68 Ga-FAPI-46 PET/CT plus CE-CT, 18F-FDG PET/CT plus CE-CT, and CE-CT alone were 91.2% (1540/1688), 82.5% (1393/1688) and 60.2% (1016/1688). The detection rates were significantly higher for 68 Ga-FAPI-46 PET/CT plus CE-CT than for 18F-FDG PET/CT plus CE-CT (p < 0.02 for primary lesions and p < 0.001 for total, abdominopelvic nodal, liver and other visceral lesions) and CE-CT (p < 0.0001 for total, primary, cervicothoracic nodal, abdominopelvic nodal, liver, other visceral, and bone lesions). In the sub-analysis, sensitivity, specificity, positive and negative predictive value, and accuracy were 61.3%, 96.7%, 81.4%, 91.4% and 90.0% for 68 Ga-FAPI-46 PET/CT plus CE-CT, 57.0%, 95.7%, 75.7%, 90.5% and 88.4% for 18F-FDG PET/CT plus CE-CT, and 51.6%, 97.2%, 81.4%, 89.6% and 88.6% for CECT, respectively.

CONCLUSIONS

68 Ga-FAPI-46 PET/CT plus CE-CT demonstrates a higher tumor detection rate than 18F-FDG PET/CT plus CE-CT and CE-CT in a diverse spectrum of malignancies, especially for primary, abdominopelvic nodal, liver, and other visceral lesions. Further studies on which entities draw particular benefit from 68 Ga-FAPI-46 PET/CT are warranted to aid appropriate diagnostic workup.

TRIAL REGISTRATION

A total of N = 232 patients were analyzed. Of these, N = 50 patients were included in a prospective interventional trial (NCT05160051), and N = 175 in a prospective observational trial (NCT04571086) for correlation and clinical follow-up of PET findings; N = 7 patients were analyzed retrospectively.

Diseases Involving the Lung Peribronchovascular Region: A CT Imaging Pathologic Classification

TOPIC IMPORTANCE

Chest CT imaging holds a major role in the diagnosis of lung diseases, many of which affect the peribronchovascular region. Identification and categorization of peribronchovascular abnormalities on CT imaging can assist in formulating a differential diagnosis and directing further diagnostic evaluation.

REVIEW FINDINGS

The peribronchovascular region of the lung encompasses the pulmonary arteries, airways, and lung interstitium. Understanding disease processes associated with structures of the peribronchovascular region and their appearances on CT imaging aids in prompt diagnosis. This article reviews current knowledge in anatomic and pathologic features of the lung interstitium composed of intercommunicating prelymphatic spaces, lymphatics, collagen bundles, lymph nodes, and bronchial arteries; diffuse lung diseases that present in a peribronchovascular distribution; and an approach to classifying diseases according to patterns of imaging presentations. Lung peribronchovascular diseases can appear on CT imaging as diffuse thickening, fibrosis, masses or masslike consolidation, ground-glass or air space consolidation, and cysts, acknowledging that some diseases may have multiple presentations.

SUMMARY

A category approach to peribronchovascular diseases on CT imaging can be integrated with clinical features as part of a multidisciplinary approach for disease diagnosis.

Multiple cavitary pulmonary metastases from pancreatic cancer diagnosed using transbronchial lung cryobiopsy

Multiple cavitary pulmonary metastases are rare, and cavitary lung lesions have various aetiologies and differential diagnoses. Therefore, radiological diagnosis of lung cavities is extremely difficult. Herein, we report a case of pancreatic cancer with multiple cavitary pulmonary metastases diagnosed using transbronchial lung cryobiopsy (TBLC), that required differentiation from pulmonary lesions of Sjögren's syndrome whose pulmonary manifestation may present as bronchiectasis and cystic change. TBLC may be useful for the diagnosis of multiple lesions because sufficiently large specimens can be obtained to allow pathological evaluation of the lung parenchyma and bronchiolar lesions.

Establishment of a Transplantation Model of PDAC-Derived Liver Metastases

BACKGROUND

The highly metastatic nature of pancreatic ductal adenocarcinoma (PDAC) and the difficulty to achieve favorable patient outcomes emphasize the need for novel therapeutic solutions. For preclinical evaluations, genetically engineered mouse models are often used to mimic human PDAC but frequently fail to replicate synchronous development and metastatic spread. This study aimed to develop a transplantation model to achieve synchronous and homogenous PDAC growth with controlled metastatic patterns in the liver.

METHODS

To generate an orthotopic PDAC model, the DT6606 cell line was injected into the pancreas head of C57BL/6 mice, and their survival was monitored over time. To generate a heterotopic transplantation model, growing doses of three PDAC cell lines (DT6606, DT6606lm, and K8484) were injected into the portal vein of mice. Magnetic resonance imaging (MRI) was used to monitor metastatic progression, and histologic analysis was performed.

RESULTS

Orthotopically injected mice succumbed to the tumor within an 11-week period (average survival time, 78.2 ± 4.45 days). Post-mortem examinations failed to identify liver metastasis. In the intraportal model, 2 × 105 DT6606 cells resulted in an absence of liver metastases by day 21, whereas 5 × 104 DT6606lm cells and 7 × 104 K8484 cells resulted in steady metastatic growth. Higher doses caused significant metastatic liver involvement. The use of K8484 cells ensured the growth of tumors closely resembling the histopathologic characteristics of human PDAC.

CONCLUSIONS

This report details the authors' efforts to establish an "optimal" murine model for inducing metastatic PDAC, which is critical for advancing our understanding of the disease and developing more effective treatments.

A case of lung metastasis from gastric cancer presenting as ground-glass opacity dominant nodules

BACKGROUND

Most metastatic lung tumors present as solid nodules on chest computed tomography (CT). In contrast, ground-glass opacity on chest computed tomography usually suggests low-grade malignant lesions such as adenocarcinoma in situ or atypical adenomatous hyperplasia of the lung.

CASE PRESENTATION

A 75-year-old woman with a history of gastric cancer surgery approximately 5 years prior was referred to the Department of Thoracic Surgery at our hospital because of two newly appearing pulmonary ground-glass opacity-dominant nodules on chest computed tomography. She had two ground-glass opacities in the right lower lobe, one in the S6 segment was 12 mm and the other in the S10 segment was 8 mm. On chest computed tomography 15 months prior to referral, the lesion in the S6 segment was 8 mm, and the lesion in the S10 segment was 2 mm. She was suspected to have primary lung cancer and underwent wide-wedge resection of the nodule in the S6 segment. In the resected specimen, polygonal tumor cells infiltrated the alveolar septa, with some tumor cells exhibiting signet ring cell morphology. Based on morphological similarities to the tumor cells of previous gastric cancers and the results of immunostaining, the patient was diagnosed with lung metastases of gastric cancer.

CONCLUSIONS

Pulmonary nodules in patients with a history of cancer in other organs, even if ground-glass opacity is predominant, should also be considered for the possibility of metastatic pulmonary tumors if they are growing rapidly.

2021 WHO Classification of Lung Cancer: Molecular Biology Research and Radiologic-Pathologic Correlation

The 2021 World Health Organization (WHO) classification system for thoracic tumors (including lung cancer) contains several updates to the 2015 edition. Revisions for lung cancer include a new grading system for invasive nonmucinous adenocarcinoma that better reflects prognosis, reorganization of squamous cell carcinomas and neuroendocrine neoplasms, and description of some new entities. Moreover, remarkable advancements in our knowledge of genetic mutations and targeted therapies have led to a much greater emphasis on genetic testing than that in 2015. In 2015, guidelines recommended evaluation of only two driver mutations, ie, epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) fusions, in patients with nonsquamous non-small cell lung cancer. The 2021 guidelines recommend testing for numerous additional gene mutations for which targeted therapies are now available including ROS1, RET, NTRK1-3, KRAS, BRAF, and MET. The correlation of imaging features and genetic mutations is being studied. Testing for the immune biomarker programmed death ligand 1 is now recommended before starting first-line therapy in patients with metastatic non-small cell lung cancer. Because 70% of lung cancers are unresectable at patient presentation, diagnosis of lung cancer is usually based on small diagnostic samples (ie, biopsy specimens) rather than surgical resection specimens. The 2021 version emphasizes differences in the histopathologic interpretation of small diagnostic samples and resection specimens. Radiologists play a key role not only in evaluation of tumor and metastatic disease but also in identification of optimal biopsy targets. ©RSNA, 2024 Test Your Knowledge questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Radiologic patterns of distant organ metastasis in advanced breast cancer patients: Prospective review of computed tomography images

BACKGROUND

Breast cancer (BC) metastases to the abdomen and pelvis affect the liver, mesentery, retroperitoneum, peritoneum, bladder, kidney, ovary, and uterus. The study documented the radiological pattern and features of the chest, bone, abdominal and pelvic (AP) metastases among advanced BC patients.

AIM

The aim is to document the radiological pattern and features of breast cancer metastasis in the chest, abdomen, pelvis and bones.

MATERIALS AND RESULTS

Chest, abdominal, and pelvic computed tomography scan images of 36 patients with advanced BC were collated from Cape Coast Teaching Hospital and RAAJ Diagnostics. The images were prospectively assessed for metastasis to the organs of the chest, AP soft tissues, and bones. Radiologic features of metastasis of the lungs, liver, lymph nodes (LNs), and bones were documented. Patients' demographics, clinical data, and histopathology reports were also collected. The data were captured using UVOSYO and exported to Microsoft Excel templates. The data obtained were descriptively analyzed. Only 2.8% of BCs exhibited metaplastic BC, whereas 97.2% had invasive ductal BC. Triple-negative cases were 55.6%. Of 36 patients, 31 (86.1%), 21 (58.3%), and 14(38.8%) were diagnosed of chest, AP, and bone tissues metastasis, respectively. LN involvement was reported in 26 (72.2%) patients. Majority, 21 (58.3%) were diagnosed of multiple sites metastasis with 15 (41.7%) showing single site. Lungs (77.4%, 24/31) and liver (47.6%, 10/21) were the most affected distant organs. Most bone metastases were lytic lesions (92.9%, 13/14) with the vertebrae (85.7%, 12/14) been the most affected.

CONCLUSION

According to the study, advanced BC patients have a higher-than-average radiologic incidence of lung, liver, bone, and LN metastases.

Imaging of Pancreatic Ductal Adenocarcinoma: An Update on Recent Advances

Pancreatic ductal carcinoma (PDAC) is one of the leading causes of cancer-related death worldwide. Computed tomography (CT) remains the primary imaging modality for diagnosis of PDAC. However, CT has limitations for early pancreatic tumor detection and tumor characterization so that it is currently challenged by magnetic resonance imaging. More recently, a particular attention has been given to radiomics for the characterization of pancreatic lesions using extraction and analysis of quantitative imaging features. In addition, radiomics has currently many applications that are developed in conjunction with artificial intelligence (AI) with the aim of better characterizing pancreatic lesions and providing a more precise assessment of tumor burden. This review article sums up recent advances in imaging of PDAC in the field of image/data acquisition, tumor detection, tumor characterization, treatment response evaluation, and preoperative planning. In addition, current applications of radiomics and AI in the field of PDAC are discussed.

Pancreatic cancer Masquerading as lung nodules: A Diagnostic Dilemma

To our knowledge, this is the first report of isolated pulmonary nodules as an initial presentation of underlying pancreatic cancer. We present a case of metastatic pancreatic cancer which manifested as worsening bilateral pulmonary nodules and normal abdominal imaging in a 72-year-old female patient. A navigational bronchoscopy with biopsy of lung nodules was performed which showed poorly differentiated adenocarcinoma. Carcinoembryonic antigen and CA 19-9 levels were elevated so endoscopic ultrasound with fine needle aspiration was done which revealed an underlying occult pancreatic adenocarcinoma. The patient was treated with chemotherapy. Patients with pulmonary metastasis have been shown to confer longer survival as compared to metastatic disease involving other organs. We have briefly reviewed the epidemiology, clinical characteristics and management of such cases in our report.