The incidental pulmonary nodule in a child. Part 2: Commentary and suggestions for clinical management, risk communication and prevention

Imaging features and clinical evaluation of pulmonary nodules in children

Background

With the widespread use of computed tomography (CT), the detection rate of pulmonary nodules in children has gradually increased. Due to the lack of epidemiological evidence and clinical guideline on pulmonary nodule treatment in children, we aimed to provide a reference for the clinical diagnosis and management of pediatirc pulmonary nodules.

Methods

This retrospective study collected consecutive cases from April 2012 to July 2021 in the Shanghai Children's Medical Center. The sample included children with pulmonary nodules on chest CT scans and met the inclusion criteria. All patients were categorized into tumor and non-tumor groups by pre-CT clinical diagnosis. Nodule characteristics between groups were analyzed. To establish a clinical assessment model for the benign versus malignant pulmonary nodules, patients who have been followed-up for three months were detected and a decision tree model for nodule malignancy prediction was constructed and validated.

Results

The sample comprised 1341 patients with an average age of 7.2 ± 4.6 years. More than half of them (51.7%) were diagnosed with malignancies before CT scan. 48.3% were diagnosed with non-tumor diseases or healthy. Compared to non-tumor group, children with tumor were more likely to have multiple nodules in both lungs, with larger size and often be accompanied by osteolytic or mass lesions. Based on the decision tree model, patients' history of malignancies, nodules diameter size≥5mm, and specific nodule distribution (multiple in both lungs, multiple in the right lung or solitary in the upper or middle right lobe) were important potential predictors for malignity. In the validation set, sensitivity, specificity and AUC were 0.855, 0.833 and 0.828 (95%CI: 0.712-0.909), respectively.

Conclusion

This study conducted a clinical assessment model to differentiate benignity and malignancy of pediatric pulmonary nodules. We suggested that a nodule's diameter, distribution and patient's history of malignancies are predictable factors in benign or malignant determination.

Solitary pulmonary nodule in an early adolescent

An early adolescent boy presented with 1-week history of left-sided chest pain, localised to the anterior aspect of seventh intercostal space. A chest radiograph revealed a round opacity measuring 2.6×2.4 cm in the left mid zone. A CT scan of the chest confirmed a solitary well-circumscribed pulmonary nodule measuring 2.7×2.4 cm in the central left upper lobe, adjacent to the anterior segmental bronchus. Positron emission tomography scan showed mild to moderate fluorodeoxyglucose uptake (maximum standardized uptake value 5.2) in the nodule. He underwent a video-assisted left upper lobectomy. Histology of the nodule was consistent with sclerosing pneumocytoma, a rare benign lung neoplasm that occurs predominantly in middle-aged women of Asian descent. This case highlights the challenges in diagnosis and management of solitary pulmonary nodules in children, especially those who remain symptomatic or only have minimal symptoms and provides a pragmatic approach to this condition.

Pulmonary Nodules in Juvenile Systemic Sclerosis: A Case-Series from the National Registry for Childhood Onset Scleroderma (NRCOS)

BACKGROUND

Juvenile systemic sclerosis (jSSc) is a systemic inflammatory and fibrotic autoimmune disease. Adult guidelines recommend obtaining a screening high-resolution computed tomography scan (CT) at diagnosis. As these recommendations are adopted as standard of care for jSSc, increased screening with CT may lead to increased detection of nodules. The implications of nodules identified in jSSc are unclear and unreported.

METHODS

A retrospective chart review was performed on the prospectively enrolled National Registry for Childhood-Onset Scleroderma (NRCOS) cohort over an enrollment period of 20 years. Clinical associations with presence of nodules and nodule characteristics were investigated.

RESULTS

In this jSSc cohort, the prevalence of pulmonary nodules was 31% (n = 17 of 54). Nodule characteristics were heterogeneous, and most displayed stability over time. More participants with nodules had structural esophageal abnormalities, restriction, and reduced diffusing capacity on lung function tests, and follow-up imaging. Most participants had multiple nodules, and although most nodules were <5 mm, most participants had at least one nodule >5 mm.

CONCLUSIONS

Pulmonary nodules are seen in children with jSSc and may be related to more severe disease and/or esophageal dysfunction. More work is needed to provide guidance on radiologic follow-up and clinical management of pulmonary nodules in jSSc.

Pediatric Pulmonary Nodules: Imaging Guidelines and Recommendations

Incidental pulmonary nodules are not infrequently identified on computed tomography imaging in the pediatric population and can be a challenge in suggesting appropriate follow-up recommendations. An evidence-based and practical imaging approach for diagnosis and appropriate directed management is essential for optimal patient care. This article provides an up-to-date review of the pediatric pulmonary nodule literature and suggests a practical algorithm to manage pulmonary nodules in the pediatric population.

Atypical pulmonary metastases in children: the spectrum of radiologic findings

Pulmonary nodules present a diagnostic challenge when they appear as atypical metastases in pediatric oncology patients. Chest computed tomography (CT) is the primary imaging modality for assessing lung nodules. In pediatric populations, Wilms tumor and osteosarcoma are the cancers most likely to produce pulmonary metastasis, both typical and atypical. This pictorial essay provides a thorough description of the specific radiologic features of atypical pediatric pulmonary metastases, and their pathogenesis and differential diagnosis. We also address diagnostic approaches to incidental lung nodules in healthy children found in the literature. Our aim is to help radiologists identify atypical lung metastases on CT, ensuring that children receive prompt, and potentially lifesaving, treatment.

CT Features of Benign Intrapulmonary Lymph Nodes in Pediatric Patients With Known Extrapulmonary Solid Malignancy

OBJECTIVE. The purpose of our study was to determine the CT features of benign intrapulmonary lymph nodes in pediatric patients with known extrapulmonary solid malignancy. MATERIALS AND METHODS. A retrospective review of surgical pathology archives was performed to identify consecutive chest CT studies of pediatric patients (≤ 18 years) with extrapulmonary solid malignancy and histologically confirmed benign intrapulmonary lymph nodes between January 1, 2004, and March 15, 2020. CT features of intrapulmonary lymph nodes-including size, shape, margin, type, associated calcification or fat, and location-were independently evaluated by two pediatric radiologist reviewers. The CT features of benign intrapulmonary lymph nodes in pediatric patients were analyzed using summary statistics. Interobserver agreement was measured with the kappa coefficient. RESULTS. There were 36 pathology-confirmed benign intrapulmonary lymph nodes in 27 pediatric patients (18 boys and nine girls; mean age, 12 years; age range, 1-18.2 years). Twenty-three (63.9%) of the benign intrapulmonary lymph nodes were biopsied from the right lung and 13 (36.1%) from the left lung (p = .03). The mean size, determined from CT studies, of benign intrapulmonary lymph nodes was 3.6 mm (SD, 1.4 mm; range, 1.3-7.8 mm). Triangular shape (25/36, 69.4%) was the most common shape of the benign intrapulmonary lymph nodes. Less commonly seen shapes of benign intrapulmonary lymph nodes were oval (6/36, 16.7%), round (3/36, 8.3%), and trapezoidal (2/36, 5.6%). All benign intrapulmonary lymph nodes were smoothly marginated and solid without associated calcification or fat. Of the 36 benign intrapulmonary lymph nodes, 15 (41.7%) were pleura-based; 11 (30.6%), perifissural; and 10 (27.8%), parenchymal. The kappa value for interobserver agreement between the two reviewers was 0.917 (95% CI, 0.825-1.000; standard error, 0.047), which corresponds to near-perfect agreement. CONCLUSION. In pediatric patients with known extrapulmonary solid malignancy, benign intrapulmonary lymph nodes are subcentimeter (mean size, 3.6 mm), smoothly marginated, and solid without containing calcification or fat on CT. In particular, triangular shape was the most commonly encountered shape of a benign intrapulmonary lymph node.

Practical management of pulmonary nodules in the most common pediatric tumors

In pediatric patients with sarcomas, hepatoblastomas, or other types of primary tumors, lung metastases are often found at diagnosis or during follow-up. The wide variety of primary tumors and clinical situations makes management and follow-up of these patients challenging. Chest CT is the best way to detect the dissemination of disease to the lungs. Many pulmonary nodules are nonspecific, and many might not be pathological. Others have characteristics that make them suspicious. Although there are some general features that indicate that a pulmonary nodule is likely to be a metastasis, sometimes the meaning of these features depends on the primary tumor. Furthermore, metastases can develop during the course of the disease, and the protocols for follow-up are different for different primary tumors. We review the different protocols used at our hospital for the primary tumors that most often metastasize to the lungs, including the criteria for lung metastases and the follow-up for each primary tumor.

A 16-Year-Old Boy With Cough and Fever in the Era of COVID-19

A 16-year-old white boy with a history of chronic lung disease of prematurity, cough-variant asthma, and incidental lung nodules presented to the emergency center in spring 2020 with acute onset dry cough, shortness of breath, and fever. An initial history, gathered from his mother because of the patient's respiratory distress, revealed no recent travel. However, his mother is a health care worker at a hospital, and sick contacts included ongoing contact with a friend with cold-like symptoms. He had a variety of animals at home, including a dog, cats, fish, rodents, and reptiles. He had a history of vaping tobacco products >6 months ago. Fever and respiratory symptoms were associated with fatigue, chest tightness, abdominal pain, and myalgias. On examination, he was ill appearing and had tachycardia, tachypnea, borderline hypoxia with an oxygen saturation of 91% on room air, diminished breath sounds at the lung bases, and unremarkable abdominal examination results. A chest radiograph was consistent with the lung examination, revealing bilateral lower lobe hazy infiltrates. He showed initial improvement for 48 hours with antibiotics, intravenous fluid resuscitation, oxygen via nasal cannula, albuterol, and prednisone. Subsequently, he worsened with persistent high fever, increasing respiratory distress with pulmonary findings, and severe persistent epigastric pain, which added a layer of diagnostic complexity. As this patient's clinical course evolved and further history became available, pulmonary medicine and infectious diseases services were consulted to guide diagnostic evaluation and treatment of this patient early in the era of coronavirus disease 2019.

Clinical implications of pulmonary nodules detected in children

INTRODUCTION

The management of children found to have pulmonary nodules is not well established. We determined how often diagnostic testing was pursued, the outcome of diagnostic testing, and how often pulmonary nodules were given a definitive diagnosis.

METHOD

A retrospective review of patients found to have pulmonary nodules. Patients with oncologic diagnoses were excluded. Data collected included number of nodules, presence of pre-existing systemic disease, laboratory testing, presence of respiratory symptoms, repeat imaging, biopsy result, and final diagnosis.

RESULTS

We identified 88 patients, of which 56 (64%) had a single nodule, 21 (24%) had a pre-existing nononcologic systemic disease, and four patients (5%) had a new systemic disease identified at the same time the nodule(s) was found. In otherwise healthy patients presenting with a solitary nodule, 94% did not have a definitive diagnosis and none went on to be diagnosed with systemic disease. Serum infectious work-up result for tuberculosis, coccidioidomycosis, histoplasmosis, or aspergillosis was not significantly different between single and multiple nodule/systemic illness groups. No previously healthy patients presenting with a solitary nodule were later diagnosed with malignancy.

CONCLUSION

Diagnostic workup for a solitary pulmonary nodule was often inconclusive, especially if the patient did not have symptoms at presentation. Pulmonary nodules were not the sole presenting sign of systemic disease for any subjects. We suggest that in an otherwise healthy pediatric patient found to have an asymptomatic single pulmonary nodule, observation without laboratory work-up or repeat imaging is a reasonable option.

Computed Tomography-Guided Wire-Marking for Thoracoscopic Resection of Small Lung Nodules in Children

Introduction: In pediatric patients, thoracoscopic wedge-resection of pulmonary nodules is an established therapy. However, intraoperative localization of small lesions is still challenging. Purpose of this study was to evaluate the efficacy of preoperative computed tomography (CT)-guided wire-marking of small lung nodules. Materials and Methods: Between 2012 and 2017 a total of six cases receiving thoracoscopic resection of CT-marked lung nodules were analyzed. The nodules were preoperatively tagged by a wire, which was attached to the thoracic wall by sterile dressing. Characteristics of interest were stability of wire, complete resection, and prevention of open thoracotomy. Results: Six procedures were performed on five patients, including four men and one woman. Median age at intervention was 16 years (range 11-19 years). All patients had a history of primary malignancies, including osteosarcoma (n = 4) and synovial sarcoma (n = 1). A total of 10 nodules were visualized in CT of which 9 were marked by wire. The median expected size of nodules was 6 mm (range 2-23 mm). Two patients had bilateral, two left-sided and two right-sided lung lesions. There was no wire slippage. In five procedures wedge resection was possible; one case needed a near total lobe resection. In one case a mini-thoracotomy at port insertion site was performed to extract the specimen. There was no conversion to thoracotomy. Histopathology showed R0 resection in all patients. Malignancy was found in all specimens. In one patient postoperative hemorrhagic anemia necessitated transfusion. Conclusions: Preoperative wire-localization of small lung nodules is a safe and effective tool to enable thoracoscopic resection in children and to avoid thoracotomic interventions.

Clinical significance of pulmonary nodules detected on abdominal CT in pediatric patients

BACKGROUND

The clinical significance of a pulmonary nodule that is detected incidentally on CT studies in children is unknown. In addition, there is limited information regarding the management of incidentally detected pulmonary nodules discovered on abdominal CT studies in children.

OBJECTIVE

The purpose of this study was to investigate the clinical significance of incidental pulmonary nodules detected on abdominal CT studies in children.

MATERIALS AND METHODS

This was a retrospective study performed following institutional review board approval. Abdominal CT reports in patients younger than 18 years of age from July 2004 to June 2011 were reviewed for the terms "nodule," "nodular" or "mass" in reference to the lung bases. The study population included those pediatric patients in whom pulmonary nodules were initially detected on abdominal CT studies. The largest pulmonary nodules detected on CT studies were evaluated for their features (size, shape, margin, attenuation, location, and presence of calcification and cavitation). Follow-up CT studies and clinical records were reviewed for demographic information, history of underlying malignancies and the clinical outcome of the incidental pulmonary nodules. Comparison of malignant versus benign pulmonary nodules was performed with respect to the size of the nodule, imaging features on CT, and patient history of malignancy using the Student's t-test and Fisher exact test. Youden J-index in receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off size for suggesting a high risk of malignancy of incidentally detected pulmonary nodules.

RESULTS

Pulmonary nodules meeting inclusion criteria were detected in 62 (1.2%) of 5,234 patients. The mean age of patients with nodules was 11.2 years (range: 5 months-18 years). Thirty-one patients (50%) had follow-up CT studies and two of these patients (6%) were subsequently found to have malignant pulmonary nodules. Both of these patients had a history of malignancy. Of the remaining 31 patients without follow-up CT studies, none had a history of malignancy. Clinical follow-up data was available in 26 of these 31 patients (84%) and none had any evidence of malignant pulmonary nodule development. There was a significant association between history of malignancy and incidentally detected pulmonary nodules on abdominal CT studies subsequently found to be malignant (P = 0.036). The size was significantly larger for the malignant pulmonary nodules compared to the benign pulmonary nodules with a size ≥7 mm in diameter being the optimal cut-off for suggesting a high risk of malignancy (11.5 ± 6.4 mm vs. 4.7 ± 3.0 mm, P = 0.003).

CONCLUSION

The incidence of pulmonary nodules found on pediatric abdominal CT studies is 1.2%. The incidence of malignancy in such pulmonary nodules is low (3%) and only seen in the setting of pulmonary nodules ≥7 mm in diameter in children with a history of malignancy. Therefore, further investigation is warranted for pulmonary nodules that are ≥7 mm in children with a history of malignancy while further imaging work-up may not be necessary in the remaining patients in this pediatric patient population.