CT-based radiomics for differentiating peripherally located pulmonary sclerosing pneumocytoma from carcinoid

BACKGROUND

Pulmonary sclerosing pneumocytoma (PSP) and pulmonary carcinoid (PC) are difficult to distinguish based on conventional imaging examinations. In recent years, radiomics has been used to discriminate benign from malignant pulmonary lesions. However, the value of radiomics based on computed tomography (CT) images to differentiate PSP from PC has not been well explored.

PURPOSE

We aimed to investigate the feasibility of radiomics in the differentiation between PSP and PC.

METHODS

Fifty-three PSP and fifty-five PC were retrospectively enrolled and then were randomly divided into the training and test sets. Univariate and multivariable logistic analyses were carried to select clinical predictor related to differential diagnosis of PSP and PC. A total of 1316 radiomics features were extracted from the unenhanced CT (UECT) and contrast-enhanced CT (CECT) images, respectively. The minimum redundancy maximum relevance and the least absolute shrinkage and selection operator were used to select the most significant radiomics features to construct radiomics models. The clinical predictor and radiomics features were integrated to develop combined models. Two senior radiologists independently categorized each patient into PSP or PC group based on traditional CT method. The performances of clinical, radiomics, and combined models in differentiating PSP from PC were investigated by the receiver operating characteristic (ROC) curve. The diagnostic performance was also compared between the combined models and radiologists.

RESULTS

In regard to differentiating PSP from PC, the area under the curves (AUCs) of the clinical, radiomics, and combined models were 0.87, 0.96, and 0.99 in the training set UECT, and were 0.87, 0.97, and 0.98 in the training set CECT, respectively. The AUCs of the clinical, radiomics, and combined models were 0.84, 0.92, and 0.97 in the test set UECT, and were 0.84, 0.93, and 0.98 in the test set CECT, respectively. In regard to the differentiation between PSP and PC, the combined model was comparable to the radiomics model, but outperformed the clinical model and the two radiologists, whether in the test set UECT or CECT.

CONCLUSIONS

Radiomics approaches show promise in distinguishing between PSP and PC. Moreover, the integration of clinical predictor (gender) has the potential to enhance the diagnostic performance even further.

18F-Labeled Fluoro-2-Deoxyglucose Positron Emission Tomography and Computed Tomography in a Large Pulmonary Sclerosing Pneumocytoma with Contralateral Lung Metastasis

Pulmonary sclerosing pneumocytoma is an exceedingly rare neoplasm of the lung. These tumors are usually slow growing with a benign disease course but can easily be mistaken for carcinoid tumors or adenocarcinoma in cytology or histopathology specimens. Rare occurrences of metastases have been reported in the literature making ¹⁸F-labeled fluoro-2-deoxyglucose positron emission tomography and computed tomography useful for the evaluation of these tumors.

Large pulmonary sclerosing pneumocytoma in a young female: A rare lung tumor

We report a case of a 28‐year‐old female who presented with a solid mass lesion in the right middle lobe (RML). A chest computed tomography (CT) scan showed a 3.5 cm sized round and solid mass between the medial and lateral segment of the RML. The patient underwent a percutaneous lung biopsy with CT scan guidance and pathological examination showed pulmonary sclerosing pneumocytoma. RML lobectomy was performed for definitive treatment. Here, we describe this rare lung disease which presented as a large homogeneous lesion. Pulmonary sclerosing pneumocytoma should be considered in the differential diagnosis of solitary lung tumor, even if the patient is young.

Multiple sclerosing hemangioma of the right lung in a 23-year-old female patient: A case report and review of the literature

Pulmonary sclerosing hemangioma (PSH) is a relatively uncommon benign tumor of the lung, predominantly affecting young and middle-aged women. In the majority of the patients, PSH is incidentally found on physical examination and typically presents as a solitary nodule with smooth borders, as it is generally asymptomatic or lacks typical symptoms. In the present case, a 23-year-old woman was incidentally diagnosed with pulmonary nodules during routine physical examination and reported suffering from intermittent fevers for >2 months. The patient received antituberculosis therapy for 1 year; however, a computed tomography imaging examination revealed that the lesions had progressed. Finally, the patient underwent thoracoscopic lung biopsy followed by histopathological examination and the lesions were diagnosed as multiple sclerosing hemangioma. The aim of the present study was to review the relevant literature in order to improve our understanding of PSH.

pulmonary hamartoma

The radiological features of pulmonary sclerosing hemangioma (PSH) and pulmonary hamartoma are poorly specified. Thus, the present study aimed to compare and analyze the characteristics of fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in PSH versus pulmonary hamartoma. ¹⁸F-FDG PET/CT characteristic findings of 12 patients with PSH and 14 patients with pulmonary hamartoma were retrospectively reviewed. A total of 12 lesions were detected from the 12 patients with PSH, of which 3 masses exhibited calcification. The mean diameter and standardized maximum uptake value (SUVmax) were 1.9±0.7 cm and 2.6±1.0, respectively, and there was no significant correlation between the lesion size and SUVmax (P>0.05). For the 14 patients with pulmonary hamartoma, 14 lesions were found, of which 4 exhibited calcification. The mean diameter and SUVmax were 1.7±0.8 cm and 1.5±0.6, respectively, and there was a significant correlation between the size and SUVmax (r=0.625, r²=0.391, P<0.05). Although there was no significant difference between the size of PSH and pulmonary hamartoma (P>0.05), the SUVmax of PSH was significantly higher than that of pulmonary hamartoma (P<0.05). Moreover, the SUVmax of 1.95 was applied as a cutoff for the diagnosis of PSH, and the resulting sensitivity and specificity for PET/CT to differentiate PSH from pulmonary hamartoma were 83.3 and 78.6%, respectively. Although the morphological features were not specific, PSH showed significantly higher FDG accumulation than pulmonary hamartoma on PET/CT imaging, which may aid the differential diagnosis. Further studies with larger populations are warranted to confirm these study results.

Pulmonary sclerosing hemangioma with a rare symptom: A case report and review of the literature

Pulmonary sclerosing hemangioma (PSH) is a relatively rare benign tumor. However, as it occurs only rarely, the natural course of the tumor is not well understood. In the present study, a case is presented of a 35-year-old woman who underwent intermittent fevers for more than one year. This case highlighted fever as a rare symptom of PSH. Fever is possibly one of the symptoms of PSH, although it is less likely to occur. Another symptom of the patient was that the tumor grew quickly in two months. The lesion was diagnosed as multiple sclerosing hemangioma of the lung (i.e., PSH), in which papillary, solid and sclerotic patterns appeared. Immunohistochemical evaluation of the lesion revealed positive staining for thyroid transcription factor 1 (TTF1), epithelial membrane antigen (EMA), pancytokeratin (PCK) and cytoskeleton 7 (CK7). In the present case study, the biological activity of PSH was identified to be aggressive. A review of the literature was performed in order to comment further on the clinical and pathological features of this rare disease.

Whole-exome sequencing identifies recurrent AKT1 mutations in sclerosing hemangioma of lung

Pulmonary sclerosing hemangioma (PSH) is a benign tumor with two cell populations (epithelial and stromal cells), for which genomic profiles remain unknown. We conducted exome sequencing of 44 PSHs and identified recurrent somatic mutations of AKT1 (43.2%) and β-catenin (4.5%). We used a second subset of 24 PSHs to confirm the high frequency of AKT1 mutations (overall 31/68, 45.6%; p.E17K, 33.8%) and recurrent β-catenin mutations (overall 3 of 68, 4.4%). Of the PSHs without AKT1 mutations, two exhibited AKT1 copy gain. AKT1 mutations existed in both epithelial and stromal cells. In two separate PSHs from one patient, we observed two different AKT1 mutations, indicating they were not disseminated but independent arising tumors. Because the AKT1 mutations were not found to co-occur with β-catenin mutations (or any other known driver alterations) in any of the PSHs studied, we speculate that this may be the single-most common driver alteration to develop PSHs. Our study revealed genomic differences between PSHs and lung adenocarcinomas, including a high rate of AKT1 mutation in PSHs. These genomic features of PSH identified in the present study provide clues to understanding the biology of PSH and for differential genomic diagnosis of lung tumors.

Pulmonary sclerosing pneumocytoma mimicking lung cancer: Case report and review of the literature

Pulmonary sclerosing pneumocytoma (PSP) is a rare benign neoplasm that predominantly affects middle‐aged Asian women. PSP is often asymptomatic and demonstrates a solitary pulmonary nodule on radiologic examination. We report a case of PSP initially misdiagnosed as lung cancer because of strong ¹⁸F‐fluorodeoxyglucose (FDG) uptake revealed by ¹⁸F‐FDG positron emission tomography‐computed tomography scan. After surgery, pathology revealed that the tumor cells were immunopositive for epithelial membrane antigen and thyroid transcription factor‐1. The patient has been followed up without complication or recurrence.

Multiple pulmonary sclerosing hemangiomas (pneumocytoma) mimicking lung metastasis detected in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

Pulmonary sclerosing hemangioma (PSH), or the alternative name of “sclerosing pneumocytoma,” is a rare benign neoplasm. PSH is often asymptomatic and presents as a solitary or multiple pulmonary nodules on radiologic imaging studies. Few articles have been reported to describe the fluorodeoxyglucose positron emission tomography (FDG PET) findings about PSH. The authors describe an interesting but uncommonly encountered cause of false positive FDG PET scan in the thorax in a 25-year-old woman, a known case of arteriovenous malformation of oral cavity who underwent embolization and presented with incidental detection of bilateral lung nodules. She is asymptomatic and is on follow-up.

Unusual coexistence of pulmonary sclerosing hemangioma and pericardial cyst

Pulmonary sclerosing hemangioma is an uncommon tumor, thought to be a benign neoplasm. Pericardial cysts are also uncommon benign abnormalities, most often found incidentally on chest radiography. We describe the case of a 51-year-old woman in whom both lesions were incidentially detected on a routine chest radiograph. Enucleation of the pulmonary sclerosing hemangioma and simultaneous resection of the pericardial cyst were undertaken.

Synchronous occurrence of breast cancer and pulmonary sclerosing hemangioma: management and review of the literature

Pulmonary sclerosing hemangioma (PSH) is a rare tumor accounting for 0.2-1% of all primary lung tumors. Simultaneous occurrence of PSH with breast cancer has very rarely been reported in the literature. We describe here a case of simultaneous occurrence of PSH with breast cancer. A pathological diagnosis of PSH was confirmed by computed tomography (CT)-guided biopsy. Due to the patient's poor performance status and the benign nature of PSH, surgical excision was not considered and the patient was managed conservatively with regular follow-up. Although surgical excision is the preferred treatment for PSH, conservative management may be a reasonable option in carefully selected patients.