Endemic mycoses in children in North America: a review of radiologic findings.

Clinically significant endemic mycoses (fungal infections) in the United States (U.S.) include Blastomyces dermatitidis, Histoplasma capsulatum, and Coccidioides immitis/posadasii. While the majority of infections go clinically unnoticed, symptomatic disease can occur in immunocompromised or hospitalized patients, and occasionally in immune-competent individuals. Clinical manifestations vary widely and their diagnosis may require fungal culture, making the rapid diagnosis a challenge. Imaging can be helpful in making a clinical diagnosis prior to laboratory confirmation, as well as assist in characterizing disease extent and severity. In this review, we discuss the three major endemic fungal infections that occur in the U.S., including mycology, epidemiology, clinical presentations, and typical imaging features with an emphasis on the pediatric population.

Imaging findings of pulmonary blastomycosis in pediatric patients.

Blastomycosis is caused by Blastomyces dermatitidis, a thermally dimorphic fungus that lives in the form of spores in the soil in North America. The main mode of transmission is through the inhalation of these spores. Despite the importance of knowing the imaging characteristics of blastomycosis given the suggested high rates of dissemination in symptomatic children, a paucity of literature focuses on the imaging patterns of blastomycosis in the pediatric population. In this review, we describe the main imaging findings of pediatric pulmonary blastomycosis and briefly review extrapulmonary manifestations of the disease. Familiarity with these imaging manifestations is important to aid in rapid diagnosis.

North American Endemic Fungal Infections.

Histoplasmosis, blastomycosis, and coccidioidomycosis are endemic fungal infections in North America. Many infections are subclinical, and many symptomatic infections are mild. Pneumonia is the most common clinical manifestation. All can occur in immunocompetent and immunocompromised patients, with the latter at greater risk for disseminated and more severe disease. As with other acute respiratory illness, imaging can play a role in diagnosis. Knowledge of the acute and chronic imaging findings of endemic fungal infections is important for radiologists so that they can assist in establishing these often-elusive diagnoses, recognize normal evolution of imaging findings of infection, and identify complications.

Blastomycosis: The Great Pretender.

Blastomycosis is an endemic fungal infection caused by Blastomyces, a soil-dwelling dimorphic fungus found predominantly in North America. In this pictorial essay, we illustrate the varied imaging features of blastomycosis along with a brief description of the epidemiology, clinical aspects, and differential diagnosis, emphasizing clues that can help radiologists arrive at this diagnosis.

Retrospective analysis of the effects of Blastomyces antigen concentration in urine and radiographic findings on survival in dogs with blastomycosis.

BACKGROUND: The Blastomyces antigen concentration in urine (BACU) test is used to diagnose blastomycosis and monitor treatment in dogs. It is unknown if a higher BACU is associated with shorter survival. OBJECTIVES: To determine if the magnitude of BACU before treatment is associated with survival in dogs with blastomycosis. ANIMALS: Fifty-two dogs with blastomycosis. METHODS: Retrospective case review. BACU, radiographic lung severity (RLS) score (0-4 scale), and survival time up to 1 year after diagnosis were obtained through medical record review of dogs with Blastomyces dermatitidis. RESULTS: The overall survival was: discharge, 87%; 1 week, 85%; 2 months, 74%; and 6 months, 69%. BACU correlated with RLS score (rs = 0.33, P = .02). BACU and RLS scores were lower in survivors to 2 months than nonsurvivors (average BACU difference of 2.5 ng/mL, 95% confidence interval [CI]: 0.2-4.8 ng/mL, P = .04; median RLS difference of 2; range, 0-4, P = .02). Dogs with BACU <5 ng/mL and dogs with mild (0-1) RLS scores had a greater proportion surviving than those with BACU >5 ng/mL (P = .03) and dogs with severe (3-4) RLS scores (P = .04). All dogs with a BACU <5 ng/mL or mild RLS score were alive at last follow-up (median, 365 days; range, 44-365 days). In all, 68.1% of other dogs survived to 2 months (95% CI, 54.8%-84.8%). CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with lower BACU and RLS scores have improved survival; however, it is unclear what specific cutoffs should be used for prognosis.

Disseminated blastomycosis presenting as a retro-orbital mass.

A 43-year-old man with history of non-Hodgkins' lymphoma presented with unilateral eye swelling, pain and vision deficits which had been progressive over 2 months. Symptoms followed a presumed bacterial pneumonia 4 months prior. Imaging demonstrated retro-orbital soft tissue swelling with bony erosion concerning for a mass; surgical decompression was performed with histology confirming disseminated Blastomyces dermatitidis Symptoms responded rapidly to antifungal therapy with amphotericin followed by itraconazole. Orbital dissemination of blastomycosis is extremely rare; accurate diagnosis requires tissue biopsy to facilitate timely targeted therapy and minimise morbidity.

Spinal blastomycosis: unusual musculoskeletal presentation with literature review.

We report a case of a 41-year-old male who presented to our institution with a large groin mass. CT, MRI and PET imaging was performed and was concerning for a soft tissue abscess likely originating in the lumbar spine. Differential considerations included infection, with atypical infections such as tuberculosis strongly considered. Biopsy revealed fungal elements preliminarily reported as consistent with Cryptococcus neoformans but later revealed to be Blastomyces dermatitidis. The patient responded positively following the introduction of appropriate treatment. This case illustrates the imaging similarities between spinal blastomycosis, spinal tuberculosis, and other fungal infections as well as the need for biopsy to differentiate.

Endemic pulmonary fungal diseases in immunocompetent patients: an emphasis on thoracic imaging.

INTRODUCTION: Systemic endemic mycoses are prevalent in specific geographical areas of the world and are responsible for high rates of morbidity and mortality in these populations, and in immigrants and travelers returning from endemic regions. The most common fungal infections that can affect the lungs of immunocompetent patients include histoplasmosis, coccidioidomycosis, paracoccidioidomycosis, blastomycosis, sporotrichosis, aspergillosis, and cryptococcosis. Diagnosis and management of these diseases remain challenging, especially in non-endemic areas due to the lack of experience. Therefore, recognition of the various radiologic manifestations of pulmonary fungal infections associated with patients' clinical and epidemiologic history is imperative for narrowing the differential diagnosis. Areas covered: This review discusses the clinical and radiological findings of the main endemic fungal diseases affecting the lungs in immunocompetent patients. Specific topics discussed are their etiology, epidemiology, pathogenesis, clinical manifestations, methods of diagnosis, pathology and main imaging findings, especially in computed tomography. Expert commentary: Imaging plays an important role in the diagnosis and management of pulmonary fungal infection and may reveal useful signs. Although definitive diagnosis cannot be made based on imaging features alone, the use of a combination of epidemiologic, clinical and imaging findings may permit the formulation of an adequate differential diagnosis.

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.

Diagnostic Imaging and Invasive Fungal Diseases in Children.

Invasive fungal disease (IFD) is a life-threatening condition, especially in immunocompromised children. The role of diagnostic imaging in children at risk for an IFD is multifactorial, including initially detecting it, evaluating for dissemination of infection beyond the primary site of disease, monitoring the response to antifungal therapy, and assessing for potential relapse. The objective of this review was to synthesize the published literature relevant to the use of various imaging modalities for the diagnosis and management of IFD in children.

Radiology Case of the Month: TB or Not TB That is the Question.

45-year-old female presenting initially with fever, nonproductive cough, night sweats, pleuritic chest pain, fatigue and weight loss over the past month.

Probable pulmonary Blastomyomycocis in an immunocompetent person.

The current case report presents a 29-year old man who worked as a hotel guard in a city in China. The patient had fever and dry cough before and after hospitalization. Chest X-ray and CT revealed nodular and patchy lesions in both lower lungs. There were no abnormal findings in the examination of sputum and bronchoalveoular lavage fluid (BALF). He was diagnosed with pulmonary blastomycosis by histological examination of lung biopsy and treated with fluconazole. Follow-up chest CT examination demonstrated that the patient was recovered through appropriate antifungal treatment.

Case 233: Blastomycosis.

History A 35-year-old man from the upper Midwest region of the United States who had no relevant medical history initially presented to an acute care clinic with multiple small tender skin lesions. His temperature was 38.1°C, and physical examination revealed several small fluctuant masses that were draining purulent material. Skin culture of one of the draining lesions was performed at this time, but there was no subsequent bacterial growth. A diagnosis of furunculosis was made, and Bactrim (sulfamethoxazole-trimethoprim; AR Scientific, Philadelphia, Pa) and a regimen of chlorhexidine washes were prescribed. Two weeks later, the number of skin lesions had increased, and the patient had begun to experience night sweats and fevers. After an episode of hemoptysis and some unusual pain in the patient's right testicle, he presented to the emergency department. At this time, chest radiographs were obtained. The patient was admitted for additional work-up, and computed tomographic (CT) images of the chest were obtained. Physical examination at the time of admission revealed scattered 1-3-cm firm pink hyperpigmented subcutaneous nodules, several of which had overlying pustules. This examination was also notable for a palpable fullness within the right testicle. The patient was afebrile at admission. He denied a history of contact with sick people, illicit drug use, or recent travel. His social history was notable for a 20-pack-year smoking history and a recent relocation to a neighborhood with several new construction sites. Laboratory evaluation revealed leukocytosis (white blood cell count, 15.4 × 10(9)/L; normal range, [3.5-10.5] × 10(9)/L), a chemistry panel revealed a low sodium level (132 mEq/L [132 mmol/L]; normal range, 134-142 mEq/L [134-142 mmol/L]), and serum α-fetoprotein and human chorionic gonadotropin levels were normal. Ultrasonography (US) of the scrotum was performed. Serum analysis was negative for human immunodeficiency virus type 1 and type 2 RNA, and Venereal Disease Research Laboratory and rapid plasma regain test results were negative. Blood cultures were negative for bacterial growth. On the basis of chest CT findings, bronchoscopy with bronchoalveolar lavage was performed. Magnetic resonance (MR) imaging of the abdomen also was performed to further evaluate a focal area of hypoenhancement within the pancreatic tail seen on chest CT images.