Histoplasmosis mimicking primary lung cancer or pulmonary metastases

[Differential diagnosis of cystic and nodular lung diseases]

BACKGROUND

Cystic and nodular lung diseases encompass a broad spectrum of diseases with different etiologies and clinicoradiological presentations. Their differentiation is crucial for patient management but can be complex due to diseases with features of both categories and overlapping radiological patterns.

OBJECTIVE

This study aims to describe the imaging features of cystic and nodular lung diseases in high-resolution computed tomography (CT) in detail-primarily based on their etiology-in order to allow a more accurate differential diagnosis of these diseases.

MATERIALS AND METHODS

A narrative review based on current literature on the topic was conducted from a clinicoradiological perspective.

RESULTS

This paper systematically categorizes the differential diagnosis of cystic and nodular lung disease and provides insights into their radiological patterns and etiologies. It highlights the role of CT in the diagnosis of these diseases and emphasizes the importance of multidisciplinary panels combining expertise from radiology, pulmonology, rheumatology, and pathology.

CONCLUSION

Reliable differential diagnosis of cystic and nodular lung diseases, particularly based on their radiological features alone, remains difficult due to their overlapping and dynamic nature. Multidisciplinary boards should be the clinical standard for accurate work-up of these diseases, as they combine the medical history, symptoms, radiological findings, and, if necessary, histopathological examinations, thus providing a more robust framework for diagnosis and management.

A review on advances in 18F-FDG PET/CT radiomics standardisation and application in lung disease management

Radiomics analysis quantifies the interpolation of multiple and invisible molecular features present in diagnostic and therapeutic images. Implementation of 18-fluorine-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) radiomics captures various disorders in non-invasive and high-throughput manner. ¹⁸F-FDG PET/CT accurately identifies the metabolic and anatomical changes during cancer progression. Therefore, the application of ¹⁸F-FDG PET/CT in the field of oncology is well established. Clinical application of ¹⁸F-FDG PET/CT radiomics in lung infection and inflammation is also an emerging field. Combination of bioinformatics approaches or textual analysis allows radiomics to extract additional information to predict cell biology at the micro-level. However, radiomics texture analysis is affected by several factors associated with image acquisition and processing. At present, researchers are working on mitigating these interrupters and developing standardised workflow for texture biomarker establishment. This review article focuses on the application of ¹⁸F-FDG PET/CT in detecting lung diseases specifically on cancer, infection and inflammation. An overview of different approaches and challenges encountered on standardisation of ¹⁸F-FDG PET/CT technique has also been highlighted. The review article provides insights about radiomics standardisation and application of ¹⁸F-FDG PET/CT in lung disease management.

The Prevalence of Histoplasmic Skin Test in Lung Cancer Patients

Background: Histoplasmosis is a disease caused by fungus called Histoplasma capsulatum. Several studies reported cases of histoplasmosis that resembled malignancy [3]. . It is a fact that the clinical syndrome of neoplastic disease is not limited to malignancy, so that infectious diseases should be considered in the differential diagnosis. Method: This is descriptive research with consecutive samples. The sample was the patients with lung cancer aged 25-75 years old. The researcher assessed histoplasmic skin test on interdemal administered with fungal protein [5]. After being observed for allergic reaction in 48-72 hours, induration > 5mm shows positive reaction. The Result: this research included 25 samples consisting of 21 men and 4 women. The Result showed 1 person (4%) with positive histoplasmic skin test result containing squamous cell carcinoma and radiological features of solitary pulmonary nodule. There is an insignificant relationship between cancer cell types and the histoplasmic skin test results (p = 0.24). There is an insignificant relationship between histoplamic skin test result and radiological features (p = 0.48).  The Conclusion: There is one person with positive histoplasmic skin test result with squamous cell carcinoma and radiological features of solitary pulmonary nodule. 

Paediatric Histoplasmosis 2000-2019: A Review of 83 Cases

Histoplasmosis is an endemic fungal infection that is confined to specific geographical regions. Histoplasma spp. are primary pathogens that cause disease in both immunocompetent and immunocompromised patients, ranging from a single-organ (mostly affecting the lungs) infection to life-threatening disseminated disease. Knowledge about the clinical epidemiology relies on data from adult populations; little is known about the patient and disease characteristics in the paediatric population. Therefore, a structured review of published cases of paediatric histoplasmosis between 2000 and 2019 was performed. A literature search of PubMed was conducted and the epidemiological and clinical data from 83 cases were analysed. The mean age at presentation was 9.5 ± 5.5 years, and 51% were girls. Two-thirds of the children were immunocompromised. The majority of children presented with disseminated disease. The most frequently observed clinical symptoms were respiratory symptoms, alongside non-specific systemic features, including fever, myalgia, fatigue and weight loss. The mortality rate was 11%. Histoplasmosis affects children of any age. Being immunocompromised is a risk factor for severe and disseminated disease. The lack of specific presenting features leads to underreporting and delay in diagnosis. To improve the recognition and outcome of histoplasmosis in childhood, increased awareness and surveillance systems are warranted.

Esophagectomy in a patient with pulmonary histoplasmosis: A case report of surgical aspects and complications (with video)

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Histoplasmose is an unfrequented associated to esophageal carcinoma.

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Pulmonary disease may interfere in the outcome after esophagectomy.

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Vacuum treatment is a good option after anastomotic leakage.

Introduction

Esophagectomy is a challenging procedure associated with considerable morbidity. Previous pulmonary diseases, such as histoplasmosis fungal infection, may interfere in operative and postoperative outcomes after esophagectomy. Anastomotic leakage is one of the most feared complications after esophagectomy. However, new therapies developed such as vacuum procedure and esophageal prosthesis have been provenly beneficial.

Presentation of case

We present a case with squamous cell carcinoma of the mid esophagus portion on a young patient with a pulmonary histoplasmosis history. After a multidisciplinary board, the patient underwent transhiatal esophagectomy with gastric-pull up and cervical anastomosis due to pulmonary disease. The patient later developed an anastomotic leak with mediastinal abscess. We describe this complication's management via an endoscopic vacuum system, esophageal prosthesis, and exhibit a video illustrating the technique.

Discussion

We illustrate the management of esophageal cancer associated with previous pulmonary disease. Histoplasmosis may misunderstand the esophageal cancer staging, and it can contribute to anastomotic leakage occurrence. An endoscopic vacuum system is an excellent tool for treating esophagogastric anastomosis fistula after esophagectomy, even when the drainage is accumulated in the mediastinum. The esophageal prosthesis may be used after mediastinal abscess resolution.

Conclusion

Treatment of the association of esophageal cancer and histoplasmosis is feasible. However, care should be taken to avoid highly potential postoperative complications.

Differentiation of non-small cell lung cancer and histoplasmosis pulmonary nodules: insights from radiomics model performance compared with clinician observers

Background

Histoplasmosis pulmonary nodules often present in computed tomography (CT) imaging with characteristics suspicious for lung cancer. This presents a work-up decision issue for clinicians in regions where histoplasmosis is an endemic fungal infection, when a nodule suspicious for lung cancer is detected. We hypothesize the application of radiomic features extracted from pulmonary nodules and perinodular parenchyma could accurately distinguish between suspicious histoplasmosis lung nodules and non-small cell lung cancer (NSCLC).

Methods

A retrospective clinical cohort of pulmonary nodules with a confirmed diagnosis of histoplasmosis or NSCLC was collected from the University of Iowa Hospitals and Clincs. Radiomic features were extracted describing characteristics of the nodule and perinodular parenchyma regions and used to build a machine learning tool. These cases were assessed by four expert clinicians who gave a blinded risk prediction for NSCLC. Tool and observer performance were assessed by calculating the area under the curve for the receiver operating characteristic (AUC-ROC) and interclass correlation coefficient (ICC).

Results

A cohort of 71 subjects with confirmed histopathology (40 NSCLC, 31 histoplasmosis) were case-matched based on age, sex, and smoking history. Superior performance (AUC-ROC =0.89) was demonstrated using leave-one-subject out validation in the tool that incorporated radiomics from the nodule and perinodular parenchyma region extended to 100% nodule diameter. Observers had perfect intra-repeatability (ICC =1.0) and demonstrated fair inter-reader variability (ICC =0.52).

Conclusions

Radiomics have potential utility in the challenging task of differentiation between lung cancer and histoplasmosis. Expert clinician readers have high intra-repeatability but demonstrated inter-reader variability which could provide context for a supplemental radiomics-based tool.

An unusual infection in an immunocompetent male from a non-endemic area: Lessons from a vacation

Primary pulmonary histoplasmosis is found worldwide, and is particularly endemic in some areas of North America, usually those surrounding the Ohio and Mississippi river valleys. It is not common in the East Coast of the United States, and is in fact reportable in Pennsylvania. It has been rarely described in immunocompetent individuals residing in a non-endemic region. We present a case of a previously healthy middle-aged male, a Pennsylvania resident, who presented with mid-sternal chest discomfort, fatigue, chills and mild shortness of breath, and was diagnosed with primary pulmonary histoplasmosis.

Accuracy of a Novel Histoplasmosis Enzyme Immunoassay to Evaluate Suspicious Lung Nodules

BACKGROUND

Granulomas caused by infectious lung diseases present as indeterminate pulmonary nodules (IPNs) on radiography. Newly available serum enzyme immunoassay (EIA) for histoplasmosis has not been studied for the evaluation of IPNs. We investigated serum biomarkers of histoplasmosis antibodies as an indication of benign disease in IPNs from a highly endemic region.

METHODS

A total of 152 serum samples from patients presenting with pulmonary nodules ≤30 mm in maximum diameter were analyzed for histoplasmosis antibodies by immunodiffusion and EIA IgG and IgM tests. Serology and FDG-PET/CT scan diagnostic test characteristics were estimated and compared.

RESULTS

Cancer prevalence was 55% (n = 83). Thirty-nine (26%) individuals were positive for IgG histoplasmosis antibodies. Twelve samples were IgM antibody positive. Immunodiffusion serology was similar to IgM antibody results with 13 positive tests. Diagnostic likelihood ratios for benign disease were 0.62, 0.33, and 0.28 for FDG-PET/CT, IgG, and IgM antibodies, respectively. When both IgG and IgM were positive (n = 8), no nodules were cancerous and six were FDG-PET/CT avid.

CONCLUSIONS

A positive EIA test for both IgM and IgG strongly suggested histoplasmosis etiology and benign granuloma for 12% of benign nodules arising from a highly endemic region. Presence of either IgG or IgM histoplasma antibodies was associated with benign disease. The EIA test was more sensitive in assessing histoplasma exposure than immunodiffusion serology.

IMPACT

A new CLIA-certified histoplasmosis antibody EIA test measures histoplasmosis exposure, offers a possible alternative clinical diagnosis for benign IPNs, and may improve IPN evaluation while avoiding harmful invasive biopsies.

Lung Cancer Screening Reveals a Nonspiculated Nodule: Histoplasmosis

We report the case of a middle aged man, 43-pack-years active smoker, who upon radiographic screening for lung cancer found to have a non-spiculated lung nodule concerning for malignancy. Histologic evaluation of this lesion turned out to be a nodule due to Histoplasma capsulatum.

Histoplasmosis mimicking metastatic spinal tumour

Histoplasmosis is an infection caused by a fungus called Histoplasma. Diagnosis of histoplasmosis is based on the culture of biological samples and detection of fungus in tissues. Histoplasmosis can mimic malignant lesions. We report a 65-year-old, immunocompetent, male patient with back pain. We describe the main clinical and radiological characteristics in our patient who had vertebral histoplasmosis that mimicked cancer. A computed tomography scan showed lytic lesions of the right side of T4, T5, and T6 vertebral bodies. Magnetic resonance imaging displayed abnormal marrow signals in T4, T5, and T6 vertebral bodies (low signal on T1, high on T2 and short time inversion recovery (STIR)). Which was mimicking malignancy, such as haematological malignancy and metastatic bone cancer. Therefore, thoracic spinal surgery using the anterior approach was performed. An intraoperative frozen section examination and routine postoperative pathology showed thoracic histoplasmosis infection. Treatment of histoplasmosis was performed with oral itraconazole. The lesions did not progress and the patient symptomatically improved at a follow-up of 26 months.

Pulmonary nodule tracking using chest computed tomography in a histoplasmosis endemic area

OBJECTIVE

In areas with endemic histoplasmosis, incidental pulmonary nodules are common. Rate of malignancy and applicability of current tracking guidelines in these regions remain unclear.

METHODS

A total of 148 cases of incidental pulmonary nodules tracked with chest computed tomography were reviewed for radiologic characteristics, diagnosis, number, and size.

RESULTS

Of the nodules, 87.8% were benign and 12.2% malignant; 30% of nodules >20mm were malignant. Number of nodules (P=.14) and granulomatous disease (P=.71) were not related to malignant diagnosis.

CONCLUSION

Malignancy was lower than expected in nodules >20mm. Appropriate tracking guidelines for incidentally discovered nodules in histoplasmosis endemic regions must be determined.