Radiology-based diagnosis of fungal pulmonary infections in high-risk hematology patients: are we making progress?

PURPOSE OF REVIEW: In patients with hematological malignancies, high-resolution computed tomography (CT) is the recommended imaging approach for diagnosis, staging and monitoring of invasive fungal disease (IFD) but lacks specificity. We examined the status of current imaging modalities for IFD and possibilities for more effective applications of current technology for improving the specificity of IFD diagnosis. RECENT FINDINGS: Although CT imaging recommendations for IFD are largely unchanged in the last 20 years, improvements in CT scanner technology and image processing algorithms now allow for technically adequate examinations at much lower radiation doses. CT pulmonary angiography can improve both the sensitivity and specificity of CT imaging for angioinvasive molds in both neutropenic and nonneutropenic patients, through detection of the vessel occlusion sign (VOS). MRI-based approaches also show promise not only for early detection of small nodules and alveolar hemorrhage but can also be used to detect pulmonary vascular occlusion without radiation and iodinated contrast media. 18F-fluorodeoxyglucose (FDG) PET/computed tomography (FDG-PET/CT) is increasingly used to monitor long-term treatment response for IFD, but could become a more powerful diagnostic tool with the development of fungal-specific antibody imaging tracers. SUMMARY: High-risk hematology patients have a considerable medical need for more sensitive and specific imaging approaches for IFD. This need may be addressable, in part, by better exploiting recent progress in CT/MRI imaging technology and algorithms to improve the specificity of radiological diagnosis for IFD.

Sequential low-dose CT thorax scans to determine invasive pulmonary fungal infection incidence after allogeneic hematopoietic cell transplantation.

Invasive fungal disease (IFD) during neutropenia goes along with a high mortality for patients after allogeneic hematopoietic cell transplantation (alloHCT). Low-dose computed tomography (CT) thorax shows good sensitivity for the diagnosis of IFD with low radiation exposure. The aim of our study was to evaluate sequential CT thorax scans at two time points as a new reliable method to detect IFD during neutropenia after alloHCT. We performed a retrospective single-center observational study in 265/354 screened patients admitted for alloHCT from June 2015 to August 2019. All were examined by a low-dose CT thorax scan at admission (CT t0) and after stable neutrophil recovery (CT t1) to determine the incidences of IFD. Furthermore, antifungal prophylaxis medications were recorded and cohorts were analyzed for statistical differences in IFD incidence using the sequential CT scans. In addition, IFD cases were classified according to EORTC 2008. At CT t0 in 9.6% of the patients, an IFD was detected and antifungal therapy initiated. The cumulative incidence of IFD in CT t1 in our department was 14%. The use of Aspergillus-effective prophylaxis through voriconazole or posaconazole decreased CT thorax t1 suggesting IFD is statistically significant compared to prophylaxis with fluconazole (5.6% asp-azol group vs 16.3% fluconazole group, p = 0.048). In 86%, CT t1 was negative for IFD. Low-dose sequential CT thorax scans are a valuable tool to detect pulmonary IFDs and guide antifungal prophylaxis and therapies. Furthermore, a negative CT t1 scan shows a benefit by allowing discontinuation of antifungal medication sparing patients from drug interactions and side effects.

Lesion size as a prognostic factor in the antifungal treatment of pulmonary cryptococcosis: a retrospective study with chest CT pictorial review of 2-year follow up.

BACKGROUND: Pulmonary cryptococcosis (PC) is a fungal infection that can have a variable prognosis depending on several factors. The objective of this study was to analyse the characteristics of pulmonary lesions and identify prognostic factors in patients with PC who were human immunodeficiency virus (HIV) -negative and underwent antifungal treatment. METHODS: The study enrolled patients diagnosed with PC who were negative for HIV. Symptoms, CT characteristics of pulmonary lesions, serum cryptococcal capsular antigen (CrAg) titre, underlying diseases, and duration of antifungal treatment were evaluated over a 2-year follow-up. RESULTS: A total of 63 patients (40 men and 23 women) with a mean age of 50.4 years were included. Half of the patients (50.8%) were asymptomatic, and the most common symptoms were cough (44.4%), expectoration (27.0%), and fever (17.5%). Pulmonary lesions were mainly present in the peripheral and lower lobes of the lung, with 35 cases classified as nodular-type lesions and 28 cases classified as mass-type lesions. At the first, third, sixth, 12th, and 24th-month follow-ups, the median proportion of residual pulmonary lesions were 59.6%, 29.9%, 12.2%, 9.6%, and 0.0%, respectively. During antifungal treatment, the lesions of 33 patients achieved complete response, while the remaining 30 patients did not. Compared with the non-CR group, the CR group had a lower baseline serum CrAg titre (median, 1:20 vs 1:80, P < 0.01), smaller pulmonary lesion size (median area, 1.6 cm2 vs 6.3 cm2, P < 0.01), lower Hounsfield-units (HU) radiodensity (median, - 60.0 HU vs - 28.5 HU, P < 0.05), more nodular-type lesions (72.7% vs 36.7%, P < 0.01), and fewer air-bronchogram signs (18.2% vs 43.3%, P < 0.05). Multivariate logistic regression analysis showed that a larger lesion size on chest CT scans was associated with a lower likelihood of achieving complete response [OR: 0.89; 95% CI (0.81-0.97); P < 0.05]. CONCLUSIONS: PC was more commonly observed in HIV-negative men, and chest CT scans mostly revealed nodular-type lesions. After antifungal treatment, patients with smaller lesions had a better prognosis.

Pulmonary Histoplasmosis in People Living with Human Immunodeficiency Virus in French Guiana: Clinical Epidemiology, Medical Imaging and Prognostic.

BACKGROUND: Histoplasmosis is mainly described as a disseminated disease in people living with HIV (PLHIV). Compared to historical descriptions in immunocompetent individuals, knowledge is lacking on the detailed clinical and radiological findings and outcomes of pulmonary histoplasmosis (PH). Overlooked or misdiagnosed with other AIDS-defining condition, prognostic of PLHIV may be at risk because of inappropriate care. METHODS: A retrospective multicentric study was conducted in PLHIV from French Guiana between January 1988 and October 2019. Proven PH were documented through mycological direct examination, culture, or histology. Patients with concomitant respiratory infections were excluded. RESULTS: Among 65 patients, sex ratio M:F was 2.4 with a median age of 39 years [IQR 25-75%: 34-44]. Median CD4 count was 24 cells/mm3 [11-71], with histoplasmosis as the AIDS-defining condition in 88% and concomitant AIDS-defining conditions in 29%. Clinical findings were fever (89%), cough (58%), dyspnea (35%), expectoration (14%), and hemoptysis (5%). Sixty-one X-rays and 24 CT-scans were performed. On X-rays, an interstitial lung disease was mainly found (77%). On CT-scans, a nodular pattern was predominant (83%): mostly miliary disease (63%), but also excavated nodules (35%). Consolidations were present in 46%, associated with miliary disease in 21%. Thoracic lymphadenopathies were found in 58%, mainly hilar and symmetric (33%). Despite antifungal treatment, case-fatality rate at one month was 22%. CONCLUSION: When faced with an interstitial lung disease on X-rays or a miliary pattern on CT-scans in advanced PLHIV, physicians in endemic areas, apart from tuberculosis or pneumocystosis, should include histoplasmosis as part of their differential diagnoses.

Comparison of the clinical manifestations and chest CT findings of pulmonary cryptococcosis in immunocompetent and immunocompromised patients: a systematic review and meta-analysis.

OBJECTIVE: The purpose of our study was to perform a meta-analysis and systematic review to compare differences in clinical manifestations and chest computed tomography (CT) findings between immunocompetent and immunocompromised pulmonary cryptococcosis (PC) patients. METHODS: An extensive search for relevant studies was performed using the PubMed, EMBASE, Cochrane Library, and Web of Sciences databases from inception to September 30, 2021. We included studies that compared the clinical manifestations and chest CT findings between immunocompetent and immunocompromised PC patients. Study bias and quality assessment were performed using the Newcastle-Ottawa Scale (NOS). RESULTS: Nine studies involving 248 immunocompromised and 276 immunocompetent PC patients were included in our analysis. The NOS score of each eligible study was above 5, indicating moderate bias. The proportion of elderly patients (> = 60 years old) in the immunosuppressed group was significantly higher than that in the immunocompetent group (OR = 2.90, 95% CI (1.31-6.43), Z = 2.63, p = 0.01). Fever (OR = 7.10, 95% CI (3.84-13.12), Z = 6.25, p < 0.000) and headache (OR = 6.92, 95% CI (2.95-16.26), Z = 4.44, p < 0.000) were more common in immunosuppressed patients. According to thin-section CT findings, lesions were more frequently distributed in the upper lobe (OR = 1.90, 95% CI (1.07-3.37), Z = 2.2, p = 0.028) in immunocompromised individuals. The proportions of patients with cavity sign (OR = 5.11, 95% CI (2.96-8.83), Z = 5.86, p = 0.00), ground-glass attenuation (OR = 5.27, 95% CI (1.60-17.35), Z = 2.73, p = 0.01), and mediastinal lymph node enlargement (OR = 2.41, 95% CI (1.12-5.20), Z = 2.24, p = 0.03) were significantly higher in immunocompromised patients. CONCLUSION: No significant differences in nonspecific respiratory symptoms were found between immunocompromised and immunocompetent PC patients. Nevertheless, fever and headache were more common in immunocompromised patients. Among the CT findings, cavity, ground-glass attenuation, and mediastinal lymph node enlargement were more common in immunocompromised individuals.

Isolated pulmonary mucormycosis in an immunocompetent patient: a case report and systematic review of the literature.

BACKGROUND: Pulmonary mucormycosis caused by Mucorales is a highly lethal invasive fungal infection usually found in immunocompromised patients. Isolated pulmonary mucormycosis in immunocompetent patients is very rare. Here, we present a case of a 32-year-old male who developed pulmonary mucormycosis without any known immunodeficiency. CASE PRESENTATION: The patient presented to our hospital because of cough and chest pain along with blood in the sputum. He was first treated for community-acquired pneumonia until bronchoalveolar lavage fluid culture confirmed the growth of Absidia. His symptoms were relieved with the use of amphotericin B, and he eventually recovered. We also provide a systematic review of relevant literature to summarize the characteristics of pulmonary mucormycosis in immunocompetent patients. CONCLUSIONS: Pulmonary mucormycosis has variable clinical presentations and is difficult to identify. Due to its high fatality rate, clinicians should make judgements regarding suspected cases correctly and in a timely manner to avoid misdiagnosis and delayed treatment.

The clinical and radiological characteristics of pulmonary cryptococcosis in immunocompetent and immunocompromised patients.

BACKGROUND: We characterized the clinical features, radiographic characteristics, and response to treatment of immunocompetent and immunocompromised patients with pulmonary cryptococcosis (PC). METHODS: We retrospectively reviewed the medical records and radiological profiles of patients diagnosed with PC who received surgical resection between May 2015 and November 2020 in a tertiary referral center. RESULTS: A total of 21 males and 18 females were included in the study. 23 patients were immunocompetent and 20 out of the 39 were asymptomatic. Immunocompetent patients were diagnosed with PC at a younger age than immunocompromised patients (48.9 vs 57.1 years, P = 0.02). Single nodule pattern was the most frequent lesion pattern (33 out of 39, 84.6%) and right upper lobe was the most common site of location (15 out of 47, 31.9%). The majority of lesions were located peripherally (38 out of 47, 80.9%) and most lesions were 1-2 cm in diameter (30 out of 47, 63.8%). Cavitation was more likely to occur in immunocompromised patients (5 out of 11, 45.5%) than in immunocompetent patients (6 out of 36, 16.7%) (P = 0.04) and there was complete resolution of PC in all patients treated with anti-fungal therapy. CONCLUSIONS: Immunocompetent patients were diagnosed with PC at a younger age than immunocompromised patients. Single nodule pattern was the most frequent lesion pattern in PC patients. Cavitation was more likely to occur in immunocompromised patients than in immunocompetent patients.

Crazy-paving patterns as rare radiological manifestations of pulmonary cryptococcosis: a case report.

BACKGROUND: Crazy-paving patterns are rarely reported as radiological manifestations of pulmonary cryptococcosis. CASE PRESENTATION: Herein, we presented a very rare case of a crazy-paving pattern as a radiological manifestation of pulmonary cryptococcosis in a patient with primary ciliary dyskinesia. The diagnosis of pulmonary cryptococcosis and primary ciliary dyskinesia was ultimately confirmed by bronchoscopic biopsy, fungus culture, whole exome sequencing of blood, etc. The patient received flucytosine (PO, 5 g per day) and amphotericin B (IV, 70 mg per day) during hospitalization and sequential therapy with voriconazole (PO, 200 mg twice a day) after discharge. He recovered during follow-up. CONCLUSIONS: We concluded that pulmonary cryptococcosis should be considered a possible cause of crazy-paving patterns in chest CT scans.

[CT Characteristics of Consolidation Type of Pulmonary Cryptococcosis in Immunocompetent Patients].

Objective To analyze the CT characteristics of consolidation type of pulmonary cryptococcosis in immunocompetent patients,and thus improve the diagnosis of this disease. Methods A total of 20 cases with consolidation-type pulmonary cryptococcosis confirmed by pathological examinations were studied.Each patient underwent breath-hold multislice spiral CT,and 10 patients underwent contrast enhanced CT.The data including lesion number,lesion distribution,lesion density,performance of enhanced CT scan,accompanying signs,and prognosis were analyzed. Results The occurrence rates of single and multiple lesions were 80.0%(n=16)and 20.0%(n=4),respectively.In all the 16 multiple-lesion patients,the occurrence rate of unilateral lobar distribution was 56.0%(n=9).The 76 measurable lesions mainly presented subpleural distribution(71.1%,n=54)and lower pulmonary distribution(75.0%,n=57).A total of 39 lesions were detected in the 10 patients received contrast enhanced CT,in which 31 lesions(79.5%)showed homogeneous enhancement,34 lesions(87.2%)showed moderate enhancement,and all the lesions manifested angiogram sign.Consolidation lesions were accompanied by many CT signs,of which air bronchogram sign had the occurrence rate of 63.2%(n=48),including types Ⅲ(n =37)and Ⅳ(n=11).Other signs included halo signs(43/76,56.6%),vacuoles or cavities(9/76,11.8%),pleural thickening(14/20,70.0%),and pleural effusion(2/20,10.0%).After treatment,the lesions of 7 patients were basically absorbed and eventually existed in the form of fibrosis. Conclusions The lesions in the immunocompetent patients with consolidation type of pulmonary cryptococcosis usually occur in the lower lobe and close to the pleura,mainly presenting unilateral distribution.The CT angiogram signs,proximal air bronchogram signs,and halo signs are the main features of this disease,which contribute to the diagnosis.

A fully automatic deep learning system for COVID-19 diagnostic and prognostic analysis.

Coronavirus disease 2019 (COVID-19) has spread globally, and medical resources become insufficient in many regions. Fast diagnosis of COVID-19 and finding high-risk patients with worse prognosis for early prevention and medical resource optimisation is important. Here, we proposed a fully automatic deep learning system for COVID-19 diagnostic and prognostic analysis by routinely used computed tomography.We retrospectively collected 5372 patients with computed tomography images from seven cities or provinces. Firstly, 4106 patients with computed tomography images were used to pre-train the deep learning system, making it learn lung features. Following this, 1266 patients (924 with COVID-19 (471 had follow-up for >5 days) and 342 with other pneumonia) from six cities or provinces were enrolled to train and externally validate the performance of the deep learning system.In the four external validation sets, the deep learning system achieved good performance in identifying COVID-19 from other pneumonia (AUC 0.87 and 0.88, respectively) and viral pneumonia (AUC 0.86). Moreover, the deep learning system succeeded to stratify patients into high- and low-risk groups whose hospital-stay time had significant difference (p=0.013 and p=0.014, respectively). Without human assistance, the deep learning system automatically focused on abnormal areas that showed consistent characteristics with reported radiological findings.Deep learning provides a convenient tool for fast screening of COVID-19 and identifying potential high-risk patients, which may be helpful for medical resource optimisation and early prevention before patients show severe symptoms.

Pulmonary Cryptococcosis: comparison of Cryptococcal antigen detection and radiography in Immunocompetent and Immunocompromised patients.

BACKGROUND: We compared the cryptococcal antigen detection and imaging findings between immunocompetent and immunocompromised patients in whom pulmonary cryptococcosis had been diagnosed. The aim of our study was to determine whether the patient's immune status and radiography affect the detection of cryptococcal antigen. METHODS: According to whether they took immunosuppressive drugs or not, seventy and eight adult patients with pulmonary cryptococcosis were divided into two groups: the immunocompetent group and the immunocompromised group. According to the detection of CrAg, each group was divided into the CrAg+ group and the CrAg- group. Then, clinical records, laboratory examinations and computed tomography findings were collected and analyzed. RESULTS: No difference was found in baseline characteristics, clinical symptoms, and laboratory investigations. By comparing CrAg detection in these two groups, it was found that the number of CrAg+ cases in the immunocompetent group was more than that in the immunocompromised group. And in the immunocompetent group, diffuse lesions were more common in CrAg+ group and limited lesions were more frequently observed in CrAg- group. CONCLUSIONS: The patient's immune status and radiography would affect the detection of cryptococcal antigen. And serum CrAg could be a useful tool for the diagnosis of pulmonary cryptococcosis in immunocompetent patients with extensive lung involvement.

Pulmonary Mucormycosis: Risk Factors, Radiologic Findings, and Pathologic Correlation.

Pulmonary mucormycosis (PM) is an uncommon fungal infection most often seen in immunocompromised patients. The fungus grows on decaying food, soil, and animal excrement. Patients usually become infected by inhalation of spores. The most common risk factors include diabetes mellitus, hematologic malignancy, and solid organ or stem cell transplant. PM can have a nonspecific appearance at imaging. For example, early imaging may show peribronchial ground-glass opacity. Later, the disease progresses to consolidation, nodules, or masses. Because patients are usually immunocompromised, the differential diagnosis often includes invasive pulmonary aspergillosis (IPA). Various radiologic findings suggestive of PM have been identified to help differentiate it from IPA. For example, the reverse halo sign is more closely associated with PM than with IPA. The reverse halo sign is an area of ground-glass opacity surrounded by a rim of consolidation. In addition, the presence of pleural effusions and more than 10 nodules is more suggestive of PM than it is of IPA. PM can progress rapidly in neutropenic patients. Identification of the hyphae in tissue by using endobronchial or percutaneous sampling can allow differentiation from IPA and help confirm the diagnosis of mucormycosis. Because of the high mortality rate associated with PM, early identification of the disease is critical for an improved likelihood of survival. A multimodality treatment approach with antifungal agents and surgical débridement has been shown to improve outcomes. The authors review the risk factors for PM, describe its imaging appearance and disease process, and describe the treatment of the disease. ©RSNA, 2020.

Pulmonary acute graft-versus-host disease and infections after allogeneic hematopoietic stem cell transplantation in pediatric recipients: A comparative study on CT.

OBJECTIVE: To compare the chest CT patterns of acute graft-versus-host disease (aGVHD) and infections within 100 days after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in pediatric recipients to help hematologist make definitive diagnosis as early as possible. METHODS: A total of 143 pediatric recipients from January 2015 to June 2019 who were diagnosed pulmonary aGVHD or infections within 100 days after allo-HSCT were enrolled in this study. Two observers evaluated the extent and distribution (unilateral, bilateral) of the CT patterns. The patterns were then classified as ground-glass opacity (GGO) (localized, patchy, diffuse), consolidation (localized, patchy, diffuse), reticulation (localized, patchy, diffuse), nodules (localized, multiple), bronchiectasis, pleural effusion, air trapping, tree-in-bud sign, and pneumomediastinum. The onset time and radiological patterns of the two cohorts were statistically compared. RESULTS: The mean onset time of aGVHD (n = 85) and infections group (viral n = 29, bacterial n = 22, fungal n = 7, total n = 58) was 36.89 ± 24.34 (range, 10-99 days) and 23.48 ± 20.65 days (range, 4-94 days) with a significant difference (P = .001). The top three underlying diseases were acute lymphoblastic leukemia (ALL) (n = 49, 57.6%); acute myeloid leukemia (AML) (n = 24, 28.2%); and aplastic anemia (AA) (7.1%) in aGVHD group and hemophagocytic syndrome (HPS) (n = 33, 56.9%); AA (n = 9, 15.5%); and ALL (n = 6, 10.3) in infection group. GGO (41.2%) in aGVHD prevailed on CT, whereas GGO (53.4%) and consolidations (43.1%) were more prevalent in infections. The distribution of GGO showed more diffuse in aGVHD (P = .031) and symmetric while patchier GGO prefers infections (P < .001). No differences were found in the reticulation. Nodules were more common in infections (P = .004) while pleural effusion was more common in aGVHD group (P < .035). CONCLUSION: Imaging patterns of aGVHD on CT differ substantially from that of infections. Physicians and radiologists should be aware of such radiological differences in order to give accurate treatment. Notably, definite diagnosis should be made in combination with clinical manifestations, signs, and laboratory tests.

Clinical features of pulmonary cryptococcosis in thin-section CT in immunocompetent and non-AIDS immunocompromised patients.

RATIONAL AND OBJECTIVES: To compare thin-section computed tomography (CT) features of pulmonary cryptococcosis (PC) in immunocompetent and non-AIDS immunocompromised patients. MATERIALS AND METHODS: We retrospectively reviewed CT findings of 18 immunocompetent and 24 non-AIDS immunocompromised patients with clinically proven PC. Different patterns of pulmonary abnormalities between the two groups of patients were compared by Fisher's exact test. RESULTS: Pulmonary nodules were present in 37 of the 42 patients. Masses were detected in 16 patients and consolidation in 9. There were 12 patients with a solitary nodule or mass. Masses were associated with nodules in 12 patients. Consolidation was associated with nodules/masses in nine patients. The nodules/masses were associated with cavitations in 13 patients. Margination of nodules/masses was well defined in nine patients and ill-defined in 33. The abnormalities were predominantly distributed in the peripheral region of the lung (n = 29, 69.0%). The presence of cavitations in nodules/masses was significantly more frequent in non-AIDS immunocompromised than in immunocompetent patients (P = 0.001). CONCLUSIONS: The most common thin-section CT feature of PC was pulmonary nodules/masses, which were ill-defined and located peripherally. Cavitations within nodules/masses were more commonly found in non-AIDS immunocompromised patients. PC should be considered in the differential diagnosis of pulmonary nodules/masses.

Chronic granulomatous 'Aspergillus lung mass'.

The diverse clinicopathological spectrum of pulmonary aspergillosis is a consequence of varying levels of invasiveness of this ubiquitous fungus, which largely depends on the host immune response and pre-existing lung disease. The clinical presentation of pulmonary aspergillosis spans a wide spectrum from hypersensitivity to life threatening angio-invasive and disseminated disease. We report the case of a young immunocompetent male with no underlying lung disease, who presented with an incidentally detected 'infective mass' lesion in the lung associated with minimal respiratory symptoms. The diagnostic challenges posed by the unusual clinical, radiological and histological picture as well as the therapeutic dilemmas faced are discussed in this report.

Imaging Patterns of Pediatric Pulmonary Blastomycosis.

OBJECTIVE: The objective of our study was to characterize and update the radiologic patterns of pediatric pulmonary blastomycosis, and correlate the radiologic patterns with patient age. MATERIALS AND METHODS: Patients 0-18 years old with pulmonary blastomycosis who underwent chest imaging from 2005 to 2016 were included in this study. The following data were collected: age, sex, clinical information, and imaging findings including presence of extrapulmonary involvement and scarring on follow-up examinations. Concordance between radiography and CT was analyzed. RESULTS: Thirty-six patients (28 boys and eight girls) ranging in age from 3 months to 17 years (mean, 10.5 years) were identified. Consolidation was found in 94.4% of patients and was unilateral in 76.5% of cases and bilateral in 23.5%. Upper (70.6%) and middle (47.1%) lobes were more frequently involved. Air bronchograms were identified in 76.5% of patients with consolidations, masslike consolidation was found in 55.9%, cavitation in 38.2%, and bubbly pattern (i.e., multiple small cavities) in 32.4%. In all patients younger than 5 years, consolidations involved multiple lobes. In 67.6% of patients, consolidations were associated with the following additional pulmonary or pleural abnormalities: pulmonary nodules (50% of patients), diffuse patchy opacification (26.5%), reticulonodular pattern (41.2%), atelectasis (5.9%), pleural effusion (20.6%), and hilar lymphadenopathy (23.5%). Pulmonary scarring was found in 70.4% of patients. Five patients had extrapulmonary involvement. The concordance between radiography and CT was excellent for location and extension of consolidation and diagnosis of cavitation, bubbly pattern, and nodules. CONCLUSION: The most common pattern of lung involvement from pulmonary blastomycosis in our series was a combination of consolidations with bilateral lung nodules and reticulonodular opacification.

Significance of the Reverse Halo Sign in Immunocompromised Patients.

OBJECTIVE. The purpose of this study is to assess the most common causes of the reverse halo sign (RHS) in immunocompromised patients and to identify clinicoradiologic features that help in achieving a specific diagnosis. MATERIALS AND METHODS. This retrospective study included 70 patients with hematologic malignancy, neutropenia, or history of solid organ transplant or stem cell transplant who had the RHS at chest CT. Absolute neutrophil count, imaging features of the RHS, and presence of pleural effusions were noted and correlated with the specific diagnosis. A decision tree was constructed from predictive imaging features and compared with radiologist assessment for infectious versus noninfectious cause. RESULTS. Infection, including fungal and bacterial pneumonia, was the most common cause of the RHS (66%), followed by organizing pneumonia (26%). Noninfectious causes such as organizing pneumonia were more likely in the solid organ transplant group, whereas infections were more likely in patients with hematologic malignancy and stem cell transplant. Among fungal pneumonias, aspergillosis (20%) was as common as mucormycosis (19%). In univariate analysis, neutropenia, rim thickness, central ground-glass attenuation, and lesion diameter correlated with infectious cause. A decision tree using neutropenia, rim thickness, central ground-glass attenuation, and pleural effusion could differentiate infectious from noninfectious cause with accuracy of 78%, compared with radiologist accuracy of 81%. CONCLUSION. Infections are more likely to cause RHS than noninfectious processes in immunocompromised patients, and aspergillosis may be as likely overall as mucormycosis because of its higher frequency in these patients. A decision tree using clinical and imaging features can help differentiate infectious from noninfectious causes of RHS.

A case report of pulmonary Botrytis sp. infection in an apparently healthy individual.

BACKGROUND: Botrytis species are well known fungal pathogens of various plants but have not been reported as human pathogens, except as allergenic precipitants of asthma and hypersensitivity pneumonitis. CASE PRESENTATION: The asymptomatic patient was referred because of a nodule revealed by chest X-ray. Computed tomography (CT) showed a cavitary nodule in the right upper lobe of the lung. He underwent wedge resection of the nodule, which revealed necrotizing granulomas and a fungus ball containing Y-shaped filamentous fungi, which was confirmed histopathologically. Culture of the specimen yielded white to grayish cotton-like colonies with black sclerotia. We performed multilocus gene sequence analyses including three single-copy nuclear DNA genes encoding glyceraldehyde-3-phosphate dehydrogenase, heat-shock protein 60, and DNA-dependent RNA polymerase subunit II. The analyses revealed that the isolate was most similar to Botrytis elliptica. To date, the pulmonary Botrytis sp. infection has not recurred after lung resection and the patient did not require any additional medication. CONCLUSIONS: We report the first case of an immunocompetent patient with pulmonary Botrytis sp. infection, which has not recurred after lung resection without any additional medication. Precise evaluation is necessary for the diagnosis of pulmonary Botrytis infection because it is indistinguishable from other filamentous fungi both radiologically and by histopathology. The etiology and pathophysiology of pulmonary Botrytis infection remains unclear. Further accumulation and analysis of Botrytis cases is warranted.