Pulmonary hamartoma: CT findings

Why do a lung biopsy for benign lesions?

BACKGROUND

Transthoracic needle biopsy of lung lesions is a well-established procedure for the diagnosis of lung lesions. The literature focuses on the diagnosis of malignant lesions with an often reported accuracy rate of more than 90%. Experience showed that biopsy can identify sometimes incidentally, also benign lesions. There are many reasons why a biopsy is performed for a "benign lesion." First of all, it may be an unexpected diagnosis, as some benign pathologies may have misleading presentations, that are very similar to lung cancer, otherwise the reason is only to make a diagnosis of exclusion, which leads to the benign pathology already being considered in the differential diagnosis.

METHODS

This study was designed as a retrospective single-center study. We selected from our database all the lung biopsies performed under CT guidance, from 2015 to 2019 and retrospectively analysed the histological data. We selected only benign lesions describing the imaging feature and differential diagnosis with lung malignancy.

RESULTS

In our patient population, among the 969 of them that underwent biopsy, we identified 93 benign lesions (10%). Hamartomas, granulomas, slow-resolving pneumonia and cryptogenic organizing pneumonia are the pathologies that most frequently can misinterpratedas lung cancer.

CONCLUSIONS

In this brief report we want to show the percentage and type of benign lesions that are found in our lung trans-thoracic biopsy population. Among these, we identified the three most frequent benign lesions that most frequently enter the differential diagnosis with lung malignant lesions describing the classic and atypical imaging findings.

Development of a CT-Based comprehensive model combining clinical, radiomics with deep learning for differentiating pulmonary metastases from noncalcified pulmonary hamartomas: a retrospective cohort study

BACKGROUND

Clinical differentiation between pulmonary metastases and noncalcified pulmonary hamartomas (NCPH) often presents challenges, leading to potential misdiagnosis. However, the efficacy of a comprehensive model that integrates clinical features, radiomics, and deep learning (CRDL) for differential diagnosis of these two diseases remains uncertain.

OBJECTIVE

This study evaluated the diagnostic efficacy of a CRDL model in differentiating pulmonary metastases from NCPH.

METHODS

The authors retrospectively analyzed the clinical and imaging data of 256 patients from the First Medical Centre of the General Hospital of the People's Liberation Army (PLA) and 85 patients from Shanghai Changhai Hospital, who were pathologically confirmed pulmonary hamartomas or pulmonary metastases after thoracic surgery. Employing Python 3.7 software suites, the authors extracted radiomic features and deep learning (DL) attributes from patient datasets. The cohort was divided into training set, internal validation set, and external validation set. The diagnostic performance of the constructed models was evaluated using receiver operating characteristic (ROC) curve analysis to determine their effectiveness in differentiating between pulmonary metastases and NCPH.

RESULTS

Clinical features such as white blood cell count (WBC), platelet count (PLT), history of cancer, carcinoembryonic antigen (CEA) level, tumor marker status, lesion margin characteristics (smooth or blurred), and maximum diameter were found to have diagnostic value in differentiating between the two diseases. In the domains of radiomics and DL. Of the 1130 radiomics features and 512 DL features, 24 and 7, respectively, were selected for model development. The area under the ROC curve (AUC) values for the four groups were 0.980, 0.979, 0.999, and 0.985 in the training set, 0.947, 0.816, 0.934, and 0.952 in the internal validation set, and 0.890, 0.904, 0.923, and 0.938 in the external validation set. This demonstrated that the CRDL model showed the greatest efficacy.

CONCLUSIONS

The comprehensive model incorporating clinical features, radiomics, and DL shows promise for aiding in the differentiation between pulmonary metastases and hamartomas.

The diagnostic value of CT-based radiomics nomogram for solitary indeterminate smoothly marginated solid pulmonary nodules

Objectives

This study aimed to explore the value of radiomics nomogram based on computed tomography (CT) on the diagnosis of benign and malignant solitary indeterminate smoothly marginated solid pulmonary nodules (SMSPNs).

Methods

This study retrospectively reviewed 205 cases with solitary indeterminate SMSPNs on CT, including 112 cases of benign nodules and 93 cases of malignant nodules. They were divided into training (n=143) and validation (n=62) cohorts based on different CT scanners. Radiomics features of the nodules were extracted from the lung window CT images. The variance threshold method, SelectKBest, and least absolute shrinkage and selection operator were used to select the key radiomics features to construct the rad-score. Through multivariate logistic regression analysis, a nomogram was built by combining rad-score, clinical factors, and CT features. The nomogram performance was evaluated by the area under the receiver operating characteristic curve (AUC).

Results

A total of 19 radiomics features were selected to construct the rad-score, and the nomogram was constructed by the rad-score, one clinical factor (history of malignant tumor), and three CT features (including calcification, pleural retraction, and lobulation). The nomogram performed better than the radiomics model, clinical model, and experienced radiologists who specialized in thoracic radiology for nodule diagnosis. The AUC values of the nomogram were 0.942 in the training cohort and 0.933 in the validation cohort. The calibration curve and decision curve showed that the nomogram demonstrated good consistency and clinical applicability.

Conclusion

The CT-based radiomics nomogram achieved high efficiency in the preoperative diagnosis of solitary indeterminate SMSPNs, and it is of great significance in guiding clinical decision-making.

Calcified uterine leiomyoma from an 18th-century nunnery in North Italy

OBJECTIVE

To develop a differential diagnosis of a mass retrieved alongside skeletal remains in the crypt of the church of Santissima Annunziata of Valenza (Province of Alessandria, Northern Italy).

MATERIAL

A calcified mass measuring 40 × 39 mm and 17.62 × 16.3817.62 × 16.38 mm.

METHOD

The analysis utilized macroscopic assessment and histologic examination (including histochemical and immunohistochemical analyses).

RESULTS

Morphological traits include an irregular and spongy external surface. Holes of different sizes lead toward the inner part of the object. A section of the mass shows an "intertwined bundle" pattern, confirmed by microscopic examination.

CONCLUSIONS

Differential diagnosis determined the mass to be consistent with calcified leiomyoma.

SIGNIFICANCE

Identifying uterine leiomyoma adds to the paucity of paleopathological literature on the condition and to calcified tumors more broadly. It also allows for an important discussion of women's gynecological health in the past and potentially among nulliparous women.

LIMITATIONS

Neither histochemical staining nor immunohistochemical analysis demonstrated the certain muscular nature of the specimens due to the rehydration and decalcification processes, for which there are no gold standards.

SUGGESTIONS FOR FURTHER RESEARCH

Calcified masses are common in the clinical literature but remain rare in paleopathological literature. Careful excavation and improved recognition of apparently calcified masses are necessary to improve recognition, diagnosis, and interpretation.

Differentiation of Hamartomas and Malignant Lung Tumors in Single-Phased Dual-Energy Computed Tomography

This study investigated the efficacy of single-phase dual-energy CT (DECT) in differentiating pulmonary hamartomas from malignant lung lesions using virtual non-contrast (VNC), iodine, and fat quantification. Forty-six patients with 47 pulmonary lesions (mean age: 65.2 ± 12.1 years; hamartomas-to-malignant lesions = 22:25; male: 67%) underwent portal venous DECT using histology, PET-CT and follow-up CTs as a reference. Quantitative parameters such as VNC, fat fraction, iodine density and CT mixed values were statistically analyzed. Significant differences were found in fat fractions (hamartomas: 48.9%; malignancies: 22.9%; p ≤ 0.0001) and VNC HU values (hamartomas: -20.5 HU; malignancies: 17.8 HU; p ≤ 0.0001), with hamartomas having higher fat content and lower VNC HU values than malignancies. CT mixed values also differed significantly (p ≤ 0.0001), but iodine density showed no significant differences. ROC analysis favored the fat fraction (AUC = 96.4%; sensitivity: 100%) over the VNC, CT mixed value and iodine density for differentiation. The study concludes that the DECT-based fat fraction is superior to the single-energy CT in differentiating between incidental pulmonary hamartomas and malignant lesions, while post-contrast iodine density is ineffective for differentiation.

Trends in the incidence of pulmonary nodules in chest computed tomography: 10-year results from two Dutch hospitals

OBJECTIVE

To study trends in the incidence of reported pulmonary nodules and stage I lung cancer in chest CT.

METHODS

We analyzed the trends in the incidence of detected pulmonary nodules and stage I lung cancer in chest CT scans in the period between 2008 and 2019. Imaging metadata and radiology reports from all chest CT studies were collected from two large Dutch hospitals. A natural language processing algorithm was developed to identify studies with any reported pulmonary nodule.

RESULTS

Between 2008 and 2019, a total of 74,803 patients underwent 166,688 chest CT examinations at both hospitals combined. During this period, the annual number of chest CT scans increased from 9955 scans in 6845 patients in 2008 to 20,476 scans in 13,286 patients in 2019. The proportion of patients in whom nodules (old or new) were reported increased from 38% (2595/6845) in 2008 to 50% (6654/13,286) in 2019. The proportion of patients in whom significant new nodules (≥ 5 mm) were reported increased from 9% (608/6954) in 2010 to 17% (1660/9883) in 2017. The number of patients with new nodules and corresponding stage I lung cancer diagnosis tripled and their proportion doubled, from 0.4% (26/6954) in 2010 to 0.8% (78/9883) in 2017.

CONCLUSION

The identification of incidental pulmonary nodules in chest CT has steadily increased over the past decade and has been accompanied by more stage I lung cancer diagnoses.

CLINICAL RELEVANCE STATEMENT

These findings stress the importance of identifying and efficiently managing incidental pulmonary nodules in routine clinical practice.

KEY POINTS

• The number of patients who underwent chest CT examinations substantially increased over the past decade, as did the number of patients in whom pulmonary nodules were identified. • The increased use of chest CT and more frequently identified pulmonary nodules were associated with more stage I lung cancer diagnoses.

Stepwise diagnostic algorithm for high-attenuation pulmonary abnormalities on CT

High-attenuation pulmonary abnormalities are commonly seen on CT. These findings are increasingly encountered with the growing number of CT examinations and the wide availability of thin-slice images. The abnormalities include benign lesions, such as infectious granulomatous diseases and metabolic diseases, and malignant tumors, such as lung cancers and metastatic tumors. Due to the wide spectrum of diseases, the proper diagnosis of high-attenuation abnormalities can be challenging. The assessment of these abnormal findings requires scrutiny, and the treatment is imperative. Our proposed stepwise diagnostic algorithm consists of five steps. Step 1: Establish the presence or absence of metallic artifacts. Step 2: Identify associated nodular or mass-like soft tissue components. Step 3: Establish the presence of solitary or multiple lesions if identified in Step 2. Step 4: Ascertain the predominant distribution in the upper or lower lungs if not identified in Step 2. Step 5: Identify the morphological pattern, such as linear, consolidation, nodular, or micronodular if not identified in Step 4. These five steps to diagnosing high-attenuation abnormalities subdivide the lesions into nine categories. This stepwise radiologic diagnostic approach could help to narrow the differential diagnosis for various pulmonary high-attenuation abnormalities and to achieve a precise diagnosis.Critical relevance statement Our proposed stepwise diagnostic algorithm for high-attenuation pulmonary abnormalities may help to recognize a variety of those high-attenuation findings, to determine whether the associated diseases require further investigation, and to guide appropriate patient management. Key points • To provide a stepwise diagnostic approach to high-attenuation pulmonary abnormalities.• To familiarize radiologists with the varying cause of high-attenuation pulmonary abnormalities.• To recognize which high-attenuation abnormalities require scrutiny and prompt treatment.

Cross-sectional imaging review of common to uncommon lung cancer mimickers in a tertiary care oncology center

Lung cancer is the most diagnosed cancer worldwide. Many non-malignant pulmonary lesions, such as tuberculosis, fungal infection, organizing pneumonia, inflammatory myofibroblastic tumor, and IgG4 disease, can mimic lung cancer due to their overlapping morphological appearance on imaging. These benign entities with minor differentiating imaging clues may go unnoticed in a high-volume cancer institution, leading to over-investigation that may result in repeated biopsies, pointless wedge resections, and related morbidities. However, with a thorough medical history, laboratory diagnostic work-up, and careful analysis of imaging findings, one can occasionally restrict the range of possible diagnoses or arrive at a definitive conclusion. When imaging features overlap, image-guided lung sampling is crucial since histopathological analysis is the gold standard.

Washout-Computed Tomography Discriminates Pulmonary "Fat-poor" Hamartomas From Neuroendocrine Neoplasms: A Simple Method in the Radiomics Era

PURPOSE

Pulmonary hamartomas (HAs) and neuroendocrine neoplasms (NENs) are often impossible to discriminate using high-resolution computed tomography (CT) as they share morphologic features. This challenge makes differential diagnosis crucial as HAs are invariably benign, whereas NENs must be considered malignant, thus requiring them to be evaluated for surgical excision.Our aim was, therefore, to develop a simple method to discriminate between pulmonary "fat-poor" HAs and NENs using contrast-enhanced CT (CECT).

MATERIALS AND METHODS

Between September 2015 and December 2021, 95 patients with a histologically proven diagnosis of lung NENs (74) and HAs (21) and who underwent a preoperative CECT scan were initially identified through a review of our pathologic and radiologic databases. Among these, 55 cases (18 HAs and 37 NENs), which have been studied with biphasic CECT, were ultimately selected and reviewed by 3 radiologists with different levels of experience, analyzing their morphologic and enhancement features.The enhancement analysis was performed by placing a region of interest within the lesion in noncontrast (NCp), postcontrast (PCp, 55 to 65 s after intravenous contrast injection), and delayed phases (Dp, 180 to 300 s). A subgroup of 35 patients who underwent 18FDG-PET/CT was evaluated in a secondary analysis.

RESULTS

HU values were significantly different between NENs and HAs in the PCp ( P <0.001). NCp and Dp attenuation values did not show significant differences in the 2 groups. Differences in values of HUs in PCp and Dp allowed to discriminate between NENs and HAs.

CONCLUSION

Wash-out analysis, ΔHU (PCp-Dp), can perfectly discriminate pulmonary "fat-poor" HAs from NENs.

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

Growth Rates of Pulmonary Carcinoid Tumors and Hamartomas

BACKGROUND

Pulmonary nodule growth is often measured by volume doubling time (VDT), which may guide management. Most malignant nodules have a VDT of 20 to 400 days, with longer VDTs typically observed in indolent nodules. We assessed the utility of VDT in differentiating pulmonary carcinoids and hamartomas.

METHODS

A review was performed from January 2012 to October 2021 to identify patients with pathologic diagnoses and at least 2 chest computed tomography scans obtained 6 or more months apart. Visualization software was used to segment nodules and calculate diameter and volume. Volume doubling time was calculated for scans with 1-mm slices. For the remainder, estimated nodule volume doubling time (eVDT) was calculated using nodule diameter. Volume doubling times/eVDTs were placed into growth categories: less than 400 days; 400-600 days; and more than 600 days.

RESULTS

Sixty nodules were identified, 35 carcinoids and 25 hamartomas. Carcinoids were larger than hamartomas (median diameter, 13.5 vs 11.5 mm; P = 0.05). For carcinoid tumors, median VDT (n = 15) was 1485 days, and median eVDT (n = 32) was 1309 days; for hamartomas, median VDT (n = 8) was 2040 days and median eVDT (n = 25) was 2253 days. Carcinoid tumor eVDT was significantly shorter than hamartomas ( P = 0.03). By growth category, 1 of 25 hamartomas and 5 of 35 carcinoids had eVDT less than 400 days and 24 of 25 hamartomas and 27 of 35 carcinoids had eVDT more than 600 days. Of 4 carcinoid tumors with metastases, 2 had eVDT less than 400 days and 2 had eVDT more than 600 days.

CONCLUSIONS

Growth rate was not a reliable differentiator of pulmonary hamartomas and carcinoids. Slow growing carcinoids can metastasize. Radiologists should be cautious when discontinuing computed tomography follow-up based on growth rates alone.

CT imaging indications correlate with the degree of lung adenocarcinoma infiltration

Background

Ground glass nodules (GGN) of the lung may be a precursor of lung cancer and have received increasing attention in recent years with the popularity of low-dose high-resolution computed tomography (CT). Many studies have discussed imaging features that suggest the benignity or malignancy of GGN, but the extent of its postoperative pathological infiltration is poorly understood. In this study, we identified CT imaging features that indicate the extent of GGN pathological infiltration.

Methods

A retrospective analysis of 189 patients with pulmonary GGN from January 2020 to December 2021 at Shanxi Cancer Hospital was performed. Patients were classified according to their pathological type into non-invasive adenocarcinoma [atypical adenomatous hyperplasia (AAH) and adenocarcinoma in situ (AIS) in a total of 34 cases], micro-invasive adenocarcinoma (MIA) in 80 cases, and invasive adenocarcinoma (IAC) in a total of 75 cases. The general demographic data, nodule size, nodule area, solid component, CT indications and pathological findings of the three groups of patients were analyzed to predict the correlation between GGN and the degree of lung adenocarcinoma infiltration.

Results

No statistically significant differences were found among the three groups in general information, vascular signs, and vacuolar signs (P &gt; 0.05). Statistically significant differences among the three groups were found in nodule size, nodule area, lobar signs, pleural traction, burr signs, bronchial signs, and solid components (P &lt; 0.05). Logistic regression equation tests based on the statistically significant indicators showed that nodal area, lobar sign, pleural pull, burr sign, bronchial sign, and solid component were independent predictors of lung adenocarcinoma infiltration. The subject operating characteristic (ROC) curve analysis showed that nodal area is valuable in predicting GGN infiltration.

Conclusion

CT-based imaging indications are useful predictors of infiltrative adenocarcinoma manifested as pulmonary ground glass nodules.

Severe Central Airway Obstruction Secondary to a Giant Endobronchial Hamartoma: A Case Report

Central airway obstruction refers to the occlusion of more than 50% of the trachea, main stem bronchi, or lobar bronchus. It can potentially become a life-threatening condition. Pulmonary hamartomas (PH) are rare tumors with an incidence of 0.25%, constituting about 8% of all benign lung neoplasms. Only 10% of PH occur endobronchially, while the remaining appear peripherally. We present the case of a women with an endobronchial hamartoma that required emergent resection by bronchoscopy. This is 44-year-old woman, with a history of an endobronchial mass on the right main stem bronchus (RMSB) without histopathological diagnosis or surgical management. She presented with a history of chronic cough and expectoration. Upon admission, a chest X-ray was performed, showing opacities of the right lung and amputations of the RMSB. Bronchoscopy was performed and a tumor-like mass that occludes the RMSB was found, with valve effect causing intermittent occlusion. In anesthetic induction, she presents severe airway obstruction and cardiorespiratory arrest. During resuscitation maneuvers, the lesion that was obstructing the light is seen and resection was performed with electrocautery and cryotherapy probes. Histopathological report described an endobronchial chondromesenchymal hamartoma, with no signs of malignancy. The control X-ray showed adequate re-expansion of the right lung. In conclusion, although endobronchial hamartoma has a low incidence and has a slow growth rate, it can manifest as severe airway obstruction. To achieve a complete resection of an endobronchial lesion, both rigid and/or flexible bronchoscopy plus multimodal interventions are recommended.

The diagnostic value of magnetic resonance imaging compared to computed tomography in the evaluation of fat-containing thoracic lesions

Intrathoracic fat-containing lesions may arise in the mediastinum, lungs, pleura, or chest wall. While CT can be helpful in the detection and diagnosis of these lesions, it can only do so if the lesions contain macroscopic fat. Furthermore, because CT cannot demonstrate microscopic or intravoxel fat, it can fail to identify and diagnose microscopic fat-containing lesions. MRI, employing spectral and chemical shift fat suppression techniques, can identify both macroscopic and microscopic fat, with resultant enhanced capability to diagnose these intrathoracic lesions non-invasively and without ionizing radiation. This paper aims to review the CT and MRI findings of fat-containing lesions of the chest and describes the fat-suppression techniques utilized in their assessment.

Pulmonary metastases from mucinous colorectal cancers and their appearance on CT: a case series

Mucinous colorectal adenocarcinoma represents a small proportion of all colorectal cancers, characterised by mucinous tumour components. While its pattern of metastatic spread differs from that of conventional colorectal adenocarcinoma, pulmonary metastases are commonly seen in both mucinous and non-mucinous types. The assessment of pulmonary nodules in the context of malignancy is a commonly encountered problem for the radiologist given the high prevalence of benign pulmonary lesions. Low density of a pulmonary nodule on CT evaluation is one of the recognised and well-documented features of benignity that is used in the radiological assessment of such nodules. We present three cases of patients with histologically proven mucinous colorectal adenocarcinoma with evidence of pulmonary metastases. In all cases, the metastases were of low density on CT and in one case were initially suspected to represent benign hamartomatous lesions. There has been little documented about the density of mucinous pulmonary metastases on CT. We suspect the low density seen in the metastases in each case is accounted for by their high internal mucinous components. The cases presented here demonstrate the importance of recognising that mucinous colorectal metastases can be of low density and therefore mimic benign pathology. This review may help the radiologist to consider shorter interval follow-up of such lesions in the context of known mucinous neoplasms, or to investigate for an extrathoracic mucinous carcinoma in the presence of multiple low-density pulmonary nodules.

Pearls and Pitfalls in Lung Cancer CT Screening

Annual LDCT lung cancer screening is recommended by the United States Preventive Services Task Force (USPSTF) for high-risk population based on the results from the National Lung Cancer Screening Trial (NLST) that showed a significant (20%) reduction in lung cancer-specific mortality rate with the use of annual low-dose computed tomography (LDCT) screening. More recently, the benefits of lung cancer screening were confirmed by the Dutch- Belgian NELSON trial in Europe. With the implementation of lung screening in large scale, knowledge of the limitations related to false positive, false negative and other potential pitfalls is essential to avoid misdiagnosis. This review outlines the most common potential pitfalls in the characterization of screen-detected lung nodules that include artifacts in LDCT, benign nodules that mimic lung cancer, and causes of false negative evaluations of lung cancer with LDCT and PET/CT studies. Awareness of the spectrum of potential pitfalls in pulmonary nodule detection and characterization, including equivocal or atypical presentations, is important for avoiding misinterpretation that can alter patient management.

A CT-Based Radiomic Signature for the Differentiation of Pulmonary Hamartomas from Carcinoid Tumors

Radiomics is a new image processing technology developed in recent years. In this study, CT radiomic features are evaluated to differentiate pulmonary hamartomas (PHs) from pulmonary carcinoid tumors (PCTs). A total of 138 patients (78 PCTs and 60 PHs) were evaluated. The Radcloud platform (Huiying Medical Technology Co., Ltd., Beijing, China) was used for managing the data, clinical data, and subsequent radiomics analysis. Two hand-crafted radiomics models are prepared in this study: the first model includes the data regarding all of the patients to differentiate between the groups; the second model includes 78 PCTs and 38 PHs without signs of fat tissue. The separation of the training and validation datasets was performed randomly using an (8:2) ratio and 620 random seeds. The results revealed that the MLP method (RF) was best for PH (AUC = 0.999) and PCT (AUC = 0.999) for the first model (AUC = 0.836), and PC (AUC = 0.836) in the test set for the second model. Radiomics tumor features derived from CT images are useful to differentiate the carcinoid tumors from hamartomas with high accuracy. Radiomics features may be used to differentiate PHs from PCTs with high levels of accuracy, even without the presence of fat on the CT. Advances in knowledge: CT-based radiomic holds great promise for a more accurate preoperative diagnosis of solitary pulmonary nodules (SPNs).

First Computed Tomography Evidence of Pulmonary Cavitated Lipoma: Diagnosis and Management

Lipomas are the most common form of benign soft tissue tumors in humans, occurring infrequently in visceral organs. Pulmonary lipomas are seen rarely and can occur such as an endobronchial (80%) or peripheral parenchymal (20%) lesion. Less than 10 cases of lung peripheral lipoma are described in literature, none cavitated. We report the clinical case of a 51-year-old emphysematous smoker man with a peripheral intrapulmonary middle-lobe cavitating lipoma, revealed during a routine chest X-ray for emphysema, subsequently confirmed by high-resolution computed tomography (HRCT) and positron emission tomography (PET)-CT. Some hypotheses are made about the origin of cavitation. Biopsy and surgery were not done due to the fully benign nodular features at imaging. The nodule was unchanged till 2 years, last follow-up with low-dose HRCT. It is probably useful to choose a conservative approach with a follow-up, if there is a high suspicion of benignity.

Death Related to a Congenital Vascular Anomaly of Pulmonary Hamartoma Type: Malpractice or Tragic Fatality?

In forensic pathology, apparently straightforward cases can often hide rarities that, if not correctly interpreted, can alter the results of the entire investigation, leading to misinterpretations. This occurs when the investigation is conducted to assess medical malpractice. An unexpected death, with no known apparent cause, is often linked to an underlying disease process of unclear etiological origin whose nature can, unfortunately, be properly investigated only post-mortem. This presentation shows a case study, in which it was possible to reconduct the death of a patient to a natural pathology and not to medical treatment. Here, the authors illustrate a case with a hamartoma developed in chronic inflammatory conditions (bronchiectasis) that was difficult to differentiate from lung cancer due to the inability to perform specific instrumental examinations. The hamartoma, usually benign and identifiable by standard instrumental investigations, in this case, led to the patient's death precisely during the execution of a bronchoscopy. However, in the absence of a certain cause of death, public opinion unanimously attributes a patient's disease to medical error. Indeed, a routine practice such as bronchoscopy should not cause death and consequently, the doctor must have made a mistake. Fortunately, the autopsy not only demonstrated the origin of the bleeding but also unveiled the reason for this, as rare congenital lung disease. Fate, one might say.

18F-Fluciclovine-Avid Pulmonary Hamartoma

ABSTRACT

A 73-year-old man with history of grade group 1/Gleason 3 + 3 = 6 prostate adenocarcinoma status post prostatectomy had subsequent biochemical recurrence with serum prostate-specific antigen level of 2.4 ng/mL. He underwent an 18F-fluciclovine PET/CT scan that demonstrated a left prostate bed recurrence and an incidental 18F-fluciclovine-avid smooth-edged solitary lung nodule with internal fat attenuation. Such uptake of 18F-fluciclovine in a lung hamartoma could be mistaken for prostate cancer metastasis. Given the increasing use of advanced imaging for prostate cancer, there is need for the imaging specialist to know about pitfalls and how to interpret them.

Cocaine-induced pulmonary complications: A diagnosis of waiting and watching

Pulmonary complications of cocaine among users are common. Manifestations include lung congestion, intra-alveolar edema, and diffuse alveolar hemorrhage (DAH). Direct cellular toxicity, eosinophilia, barotrauma, and vasoactive effects of cocaine are believed to induce DAH. We present a rare case of cocaine-associated focal alveolar hemorrhage mimicking malignancy on imaging. Initially contemplated biopsy was avoided based on rapid growth of concerning lung lesion, with subsequent near resolution on follow-up. This case illustrates the importance of epidemiologic and temporal multimodality correlation when evaluating indeterminate lung lesions.

Managing Incidental Findings on Thoracic CT: Lung Findings. A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee presents recommendations for managing incidentally detected lung findings on thoracic CT. The Chest Subcommittee is composed of thoracic radiologists who endorsed and developed the provided guidance. These recommendations represent a combination of current published evidence and expert opinion and were finalized by informal iterative consensus. The recommendations address commonly encountered incidental findings in the lungs and are not intended to be a comprehensive review of all pulmonary incidental findings. The goal is to improve the quality of care by providing guidance on management of incidentally detected thoracic findings.

Incidental Lung Nodules on Cross-sectional Imaging: Current Reporting and Management

Pulmonary nodules are the most common incidental finding in the chest, particularly on computed tomographs that include a portion or all of the chest, and may be encountered more frequently with increasing utilization of cross-sectional imaging. Established guidelines address the reporting and management of incidental pulmonary nodules, both solid and subsolid, synthesizing nodule and patient features to distinguish benign nodules from those of potential clinical consequence. Standard nodule assessment is essential for the accurate reporting of nodule size, attenuation, and morphology, all features with varying risk implications and thus management recommendations.

Contribution of 18F-FDG PET/CT in the Differential Diagnosis of Pulmonary Hamartomas and Pulmonary Carcinoids

Objectives:

This study aimed to evaluate ¹⁸fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) findings in the differential diagnosis of pulmonary carcinoids and pulmonary hamartomas.

Methods:

¹⁸F-FDG PET/CT findings of 34 patients with pulmonary carcinoids (12 atypical, 22 typical) and 32 patients with pulmonary hamartomas were retrospectively evaluated. Both mean diameter and mean maximum standardized uptake value (SUV_max) of hamartomas and carcinoids were compared by Mann-Whitney U and Kruskall-Wallis H tests.

Results:

The mean longest diameter of atypical carcinoids (3.5±1.7 cm) was higher than that of hamartomas (2.1±1 cm) (p=0.038). No significant difference was found between the mean diameter of typical carcinoids and mean diameter of hamartomas (p=0.128). The mean SUV_max of atypical carcinoids (5.97±3.7) and typical carcinoids (4.22±1.7) were higher than those of hamartomas (1.65±0.9) (p=0.002 and p=0.003, respectively). There were collapse/consolidation in 55.8%, bronchiectasis or mucoid impaction in 47%, and air trapping in 14.7% in the peripheral parenchyma of the 34 carcinoids. Collapse/consolidation was detected in a patient with endobronchial hamartoma, and other finding was not found in the parenchyma around hamartomas.

Conclusion:

The ¹⁸F-FDG uptake of pulmonary carcinoids can vary from minimal to intense. ¹⁸F-FDG uptake can be seen in pulmonary hamartomas. However, the mean SUV_max of atypical carcinoids and typical carcinoids were higher compared to hamartomas. Pulmonary carcinoid must be suspected in cases with accompanying bronchial obstruction findings in the periphery of the mass.

Rare pulmonary tumors and carcinoma mimickers; experience from an interventional radiology unit with radiologic-pathologic correlation-A pictoral essay

BACKGROUND

Although imaging findings along with patients' clinical history may give clue for the etiology of a pulmonary lesion, the differentiation of benign pulmonary lesions from lung cancer could be challenging.

OBJECTIVE

The aim of this review article was to increase the awareness of the carcinoma mimicking lung lesions.

METHODS

This paper was designed to illustrate rare pulmonary tumors and carcinoma mimickers with emphasis on radiologic-pathologic correlation. Pitfalls encountered on CT images and also false positivity of PET-CT scans were also presented.

CONCLUSION

Several benign pulmonary lesions may grow in size on follow-up and some may show pathologic FDG (18F-fluorodeoxyglucose) uptake, which makes them indistinguishable from lung carcinoma by imaging. In addition, some slow-growing malignant lesions, such as carcinoid, may be false-negative on PET/CT scans.

Pulmonary hamartoma: Feasibility of dual-energy CT detection of intranodular fat

We have reported 2 cases of pulmonary hamartoma focusing on detecting intranodular fat, which is one of CT features suggestive of pulmonary hamartoma, using dual-energy CT analyses. For patient 1, a 73-year-old man was pointed out to have a nodular opacity on chest radiograph of pretreatment workup for retinal detachment. In patient 2, a 66-year-old woman with uterine carcinoma admitted for preoperative assessment. Both patients underwent dual-energy CT examination and the pulmonary lesions exhibited a downward-sloping curve at lower X-ray energies on attenuation curve of virtual monochromatic images, which suggested fatty tissue. Dual-energy CT analysis can help diagnose pulmonary hamartoma with detection of intralesional fatty tissue.

A pulmonary hamartoma in Covid-19 pneumonia: an interesting case studied with computed tomography

Since the widespread of acute respiratory syndrome infection caused by Coronavirus-19, chest computed tomography (CT) was considered a useful imaging tool commonly used in early diagnosis and monitoring of patients with complicated Covid-19 pneumonia. Many typical imaging features of this disease were carefully described with chest CT, as well as the collateral CT findings in the lungs and mediastinum. Here we describe the case of a patient with Covid-19 pneumonia, that collaterally had a pulmonary hamartoma in the left lung, documented at CT.

The Usefulness of Imaging Quantification in Discriminating Non-Calcified Pulmonary Hamartoma From Adenocarcinoma

Background

Patients with non-calcified hamartoma were more susceptible to surgery or needle biopsy for the tough discrimination from lung adenocarcinoma. Radiomics have the ability to quantify the lesion features and potentially improve disease diagnosis. Thus, this study aimed to discriminate non-calcified hamartoma from adenocarcinoma by employing imaging quantification and machine learning.

Methods

Forty-two patients with non-calcified hamartoma and 49 patients with adenocarcinoma were retrospentation; Manual lesion segmentation, feature quantification (e.g., texture features), and artificial neural network were performed consecutively. Independent t-test was used to conduct the inter-group comparisons of those imaging features. Receiver operating characteristic curve was performed to investigate the discriminating efficacy.

Results

Significantly higher contrast, cluster prominence, cluster shade, dissimilarity, energy, and entropy in non-calcified hamartoma were observed compared with lung adenocarcinoma. Texture-grey-level co-occurrence matrix showed a well discrimination between non-calcified hamartoma and adenocarcinoma as the detection sensitivity, specificity, accuracy, and the area under the curve were 87.22% ± 9.07%, 82.64% ± 8.07%, 85.11% ± 5.40%, and 0.942, respectively.

Conclusion

Quantifying imaging features is a potentially useful tool for clinical diagnosis. This study demonstrated that non-calcified hamartoma has a heterogeneous distribution of attenuations probably resulting from its complex organizations. Based on this property, imaging quantification could improve discrimination of non-calcified hamartoma from adenocarcinoma.

Evaluation of the solitary pulmonary nodule

The solitary pulmonary nodule represents a common diagnostic challenge for clinicians. While most are benign, a significant number represent early, potentially curable lung cancers. With the increased utilisation of chest computed tomography, solitary pulmonary nodules are increasingly being identified and with lung cancer screening programmes now on the horizon globally, it is crucial clinicians are familiar with the evaluation and management of solitary pulmonary nodules. Through the evaluation of patient risk factors combined with computed tomography characteristics of solitary pulmonary nodules, including size, growth rate, margin characteristics, calcification, density and location; a clinician can assess the risk of malignancy. This article provides an up to date review of the imaging features of both benign and malignant solitary pulmonary nodules to assist in the identification of nodules that require histological confirmation or ongoing surveillance. In addition, we summarise the newly updated Fleischner Society Guidelines that provide clinicians with a framework for the evaluation and management of solitary pulmonary nodules.

Incidental endobronchial hamartoma in a patient with enchondroma

Hamartomas are the most common type of benign tumours of the lung, constituting a small portion of all lung neoplasms. Hamartomas are rare benign tumours composed of multiple mesenchymal cell lines. Two clinical types have been defined according to the location: intraparenchymal and endobronchial, more frequently the former. We present a case of endobronchial hamartoma causing significant blockage of the right middle lobe. The finding was incidental on a CT scan of the chest done for staging purposes for a large mixed lytic and sclerotic lesion that was found within the proximal-mid portion of the tibial diaphysis. The endobronchial lesion was removed by hot electrocautery snare during bronchoscopy and identified as a hamartoma. Argon plasma coagulation was applied to the lesion's base afterwards and the patient was to follow-up in 3 months for a repeat CT scan.

Surgical treatment and outcome of pulmonary hamartoma: a retrospective study of 10-year experience

Background

The present retrospective study was designed to review the clinicopathological features and outcome of surgical treatment of pulmonary hamartoma who underwent surgical operation between January 2008 and January 2018.

Methods

The information about the age and gender of patients, symptoms, history of tobacco consumption, the presence of malignancies, radiological and imaging findings, calcification in the hamartoma, location and size of the lesions, findings of preoperative diagnostic investigations, operative procedures, operative time, tube drainage duration, surgical complication, hospital stay after tumor resection, duration of follow-up, and outcome were recorded.

Results

The average size of the neoplasms was 2.72 cm. Five patients (20.8%) had malignancies, which occurred previously in two patients, and concomitantly in three patients. Twenty-four patients underwent surgical treatment which included enucleation in 14 (four cases had thoracoscopic surgery), wedge resection in 8 (six cases had thoracoscopic surgery), and lobectomy in 2 patients. A total of four postoperative complications were noted. The patients were followed up for 2-98 months.

Conclusion

Enucleation was the main choice in our series. The follow-up for a long period revealed no malignant transformation and recurrence. Due to lack of the malignance after operation in our series, we presumed that the enucleation for pulmonary hamartoma was safe enough.

Pulmonary hamartoma mimicking a mediastinal cyst-like lesion in a heavy smoker

Pulmonary hamartoma (PH) is the most common benign tumor of the lung, typically presenting as a peripheral solitary nodule with round shape and smooth margins. The main computed tomography (CT) features that allow a confident diagnosis of PH are intranodular fat and popcorn-like calcifications. However, the presence of these features within PHs is variable. Thus, a reliable diagnosis of PH cannot be formulated in approximately 30% of cases. Furthermore, PHs may occasionally show atypical CT features.

The present article reports the case of a centrally located PH with an extremely rare and previously unreported CT presentation consisting of fluid attenuation, rim enhancement and thick enhancing septa that mimicked a mediastinal cyst-like lesion.

Successful use of snare electrocautery via flexible fiberoptic bronchoscopy for removal of an endobronchial hamartoma causing chronic lung atelectasis and mimicking malignancy

We present a rare case of giant endobronchial hamartoma coexisting with lung atelectasis for more than 3 years. The small specimen initially biopsied via bronchoscope did not reveal tissue features, but some features were suspicious for squamous cell carcinoma. The lesion was removed completely using snare electrocautery combined with argon plasma coagulation via flexible fiberoptic bronchoscopy. The patient made a satisfactory recovery, and a pathological diagnosis was made. This could be a useful option in selected endobronchial tumors.

Evaluation of the solitary pulmonary nodule: size matters, but do not ignore the power of morphology

Abstract

Subsequent to the widespread use of multidetector computed tomography and growing interest in lung cancer screening, small pulmonary nodules are more frequently detected. The differential diagnosis for a solitary pulmonary nodule is extremely broad and includes both benign and malignant causes. Recognition of early lung cancers is vital, since stage at diagnosis is crucial for prognosis. Estimation of the probability of malignancy is a challenging task, but crucial for follow-up and further work-up. In addition to the clinical setting and metabolic assessment, morphological assessment on thin-section computed tomography is essential. Size and growth are key factors in assessment of the malignant potential of a nodule. The likelihood of malignancy positively correlates with nodule diameter: as the diameter increases, so does the likelihood of malignancy. Although there is a considerable overlap in the features of benign and malignant nodules, the importance of morphology however should not be underestimated. Features that are associated with benignity include a perifissural location and triangular morphology, internal fat and benign calcifications. Malignancy is suspected in nodules presenting with spiculation, lobulation, pleural indentation, vascular convergence sign, associated cystic airspace, bubble-like lucencies, irregular air bronchogram, and subsolid morphology. Nodules often show different features and combination of findings is certainly more powerful.

Teaching points

• Size of a pulmonary nodule is important, but morphological assessment should not be underestimated.

• Lung nodules should be evaluated on thin section CT, in both lung and mediastinal window setting.

• Features associated with benignity include a triangular morphology, internal fat and calcifications.

• Spiculation, pleural retraction and notch sign are highly suggestive of a malignant nature.

• Complex features (e.g. bubble-like lucencies) are highly indicative of a malignant nature.

Hamartomas from head to toe: an imaging overview

Hamartomas are tumours composed of mesenchymal tissues such as cartilage, fat, connective tissue and smooth muscle and can be found in virtually any organ system. These masses commonly develop sporadically, but are also seen in certain syndromes such as tuberous sclerosis or Carney triad. While their imaging appearance varies depending on the organ they arise from, findings are usually unique and a diagnosis can be confidently made. Radiologists must be aware of the clinical and imaging presentations of these lesions with the particular goal of avoiding unnecessary studies or invasive procedures. Furthermore, knowledge of common syndromic entities is crucial, as the radiologist may be the first to suggest the diagnosis.

Multidetector Computed Tomography Findings in Pulmonary Hamartomas: A New Fat Detection Threshold

PURPOSE

The aim of the study was to determine the accuracy of multidetector computed tomography in the evaluation of histologically confirmed pulmonary hamartomas (PHs), with a special focus on fat detection.

MATERIALS AND METHODS

Data from 55 patients who had received a histologically confirmed diagnosis of PH and had undergone 64-slice thoracic MDCT were retrospectively evaluated.

RESULTS

PHs manifested predominantly as peripheral pulmonary nodules with lobulated margins. The average lesion diameter was 1.51 cm (SD 0.6 cm). Histologic analyses identified fat content in 43/55 (78.2%) surgical specimens. The accuracy, sensitivity, and specificity of fat detection at a density threshold of -40 HU were 83.7%, 100%, and 87.2%, respectively. A threshold of -33 HU yielded better results (95.3%, 100%, and 96.3%, respectively). Popcorn-like calcifications were found in only 12/55 (21.8%) PHs and were the only imaging feature suggestive of PH in 7.2% of cases. Most (66%) lesions with popcorn-like calcifications also contained fat.

CONCLUSIONS

The adoption of a new threshold for fat content (<-33 HU) can lead to further improvements in the overall ability to detect PHs by CT.

Management of CT screen-detected lung nodule: the thoracic surgeon perspective

Implementation of lung cancer CT screening programs will increase the incidence of pulmonary nodules and require multidisciplinary efforts for devising appropriate treatment plans. The role of the thoracic surgeon is paramount in leading the discussion and shaping the treatment strategies. Management of CT screen-detected lung nodules differ from conventional lung cancer nodules given their smaller size, varied histologies and potentially indolent growth. Here we present a brief overview of the thoracic surgeon's perspective on the clinical evaluation, diagnostic tests and surgical approach to these nodules in the setting of a comprehensive lung cancer screening program.

Slight uptake of 18F-FDG on positron emission tomography in pulmonary hamartoma: A case report

The present study reports the case of a 77-year-old female that was asymptomatic at presentation and was found to possess a lesion that was incidentally identified on a computed tomography (CT) scan. The CT scan revealed a non-homogeneous, hypodense, non-lobulated solid mass, ~1.2 cm in diameter, in the left upper lobe of the lung that demonstrated minimal contrast enhancement. The following CT scan was performed only two years later. This scan revealed that the non-homogeneous round mass had increased in size to ~1.7 cm in diameter, and possessed an irregular margin, in addition to being slightly lobulated with no calcification or fat. Combined positron emission tomography and CT revealed a lobulated mass that was ~1.9 cm in diameter, demonstrating an irregular margin with involvement of the mediastinal pleura. Slight uptake of ¹⁸F-fluorodeoxyglucose was also detected. The final histological diagnosis was pulmonary hamartoma.

Imaging the solitary pulmonary nodule

The development of widespread lung cancer screening programs has the potential to dramatically increase the number of thoracic computed tomography (CT) examinations performed annually in the United States, resulting in a greater number of newly detected, indeterminate solitary pulmonary nodules (SPNs). Additional imaging studies, such as fluorodeoxyglucose F 18 (FDG)-positron emission tomography (PET), have been shown to provide valuable information in the assessment of indeterminate SPNs. Newer technologies, such as contrast-enhanced dual-energy chest CT and FDG-PET/CT, also have the potential to facilitate diagnosis of potentially malignant SPNs.