A Diagnostic Dilemma: A Case of Complicated Pneumonia With Pyelonephritis and Subclinical Myocarditis

A 41-year-old woman presented with a 3.5-month history of fever, weakness, productive cough, and burning micturition along with generalized weakness and significant weight loss. Chest X-ray revealed bilateral infiltrates and bilateral pleural effusion, and the workup suggested community-acquired pneumonia (CAP). However, the course was complicated by persistent fevers, elevated inflammatory markers, elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP), and pelvic fluid collection. Extensive investigations, including bronchoscopy and lung biopsy, failed to identify a specific pathogen. Pulmonary vasculitis and lymphoma were ruled out. Antibiotic and corticosteroid therapy resulted in clinical improvement. While the cause remains unknown, brucellosis and aspergillosis were considered but ruled out with advanced testing. The underlying etiology remains elusive, highlighting the diagnostic challenges in CAP with atypical presentations.


Introduction
Community-acquired pneumonia (CAP) typically presents with a well-defined constellation of symptoms and responds favorably to antibiotics.However, a subset of patients deviates from this classic presentation, exhibiting a prolonged and complicated course of antibiotics and corticosteroids [1,2] that necessitates a more nuanced diagnostic approach [3,4].This report describes the case of a 41-year-old woman with no significant past medical history who presented with a 3.5-month history of fever, generalized weakness, productive cough, burning micturition, and significant weight loss.Chest X-ray [5] revealed bilateral infiltrates, further suggesting pneumonia.However, the clinical picture was complicated by persistent fevers, elevated inflammatory markers [6], negative galactomannan test [7], and the presence of pleural effusions.These atypical features, combined with a negative initial workup, highlight the diagnostic challenges encountered in managing complex cases of complicated pneumonia or in a broader umbrella term organizing pneumonia [8][9][10] with unclear pathology.

Case History
A 41-year-old woman with no significant past medical history presented with a 3.5-month history of fever (up to 101.5°F), generalized weakness, productive cough with yellow sputum, burning micturition, and significant weight loss.On examination, she was febrile (100°F) with bilateral chest crepitations.No history of asthma or skin lesions was reported.There was no family history of autoimmune disorders.

Imaging
Chest CT scan showed patchy consolidation with ground-glass opacities in bilateral lungs and enlarged mediastinal lymph nodes.Chest ultrasound (USG) revealed blunted costophrenic angles.USG-guided fineneedle aspiration cytology (FNAC) of the left lower lung suggested an inflammatory lesion.Abdominal ultrasound showed mild hepatomegaly and a small liver cyst.Echocardiography revealed possible mitral valve prolapse (Table 5).

Bronchoscopy and lung biopsy
Bronchoscopy with bronchoalveolar lavage showed neutrophilic inflammation with Leuconostoc mesenteroides on culture.Lung biopsy demonstrated neutrophilic inflammation but lacked evidence of malignancy or specific infectious agents on microscopy or special stains.

Management
The patient initially received empiric broad-spectrum antibiotics (linezolid, feropenem) based on culture results.Due to persistent fevers and inflammation, corticosteroids (prednisolone) were added.The patient showed a gradual improvement with resolution of fevers and improved oxygen saturation but relapse occurred as soon as prednisolone was tapered and discontinued, thus necessitating restarting of prednisolone and maintenance.
This case report underscores the significant challenge posed by diagnosing and managing complicated pneumonia with atypical features.The patient presented with a constellation of symptoms that defied easy categorization and resolution with initial antibiotic therapy.The extensive workup, encompassing blood tests, cultures, imaging studies, and even invasive procedures like bronchoscopy and lung biopsy, failed to pinpoint a specific pathogen.
This highlights the limitations of current diagnostic tools in such complex cases.While diagnoses like tuberculosis and pulmonary vasculitis along with other autoimmune pathologies, lymphoma, brucellosis, and aspergillosis along with other infective etiologies were entertained, they were ultimately ruled out based on clinical presentation, pathology, and advanced testing.The eventual improvement with a combination of antibiotics and corticosteroids suggests an underlying inflammatory process, but the exact etiology remains elusive.
This case serves as a valuable reminder for clinicians to consider atypical presentations of pneumonia and tailor their diagnostic and therapeutic strategies accordingly.A comprehensive approach that integrates clinical features, laboratory findings, and imaging studies is crucial for navigating such complex cases.By improving our understanding of atypical pneumonia presentations, we can strive for earlier diagnosis and more effective management strategies, ultimately leading to better patient outcomes.

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Large area of dense consolidation in the left lower lobe.• Multiple small patchy areas of consolidation scattered in both lung parenchyma.• Bilateral minimal pleural effusion with underlying passive atelectasis of lung parenchyma.• Few subcentimeter to centimeter pre/bilateral paratracheal, right hilar, and subcarinal lymph nodes, with the largest one measuring 1.5x1.4cm.Imaging features are suggestive of infective etiology.USG abdomen Mildly hypoechoic left kidney -To correlate clinically to look for pyelonephritis.• Bulky uterus.• Few fine-moving internal echoes and debris were noted within urinary bladder -To correlate with urine R/M.Right-sided pleural effusion.Echocardiography Mild mitral valve prolapse was observed.The valve was not thickened and not calcified.The mitral valve score was 4/16.No mitral valve stenosis was observed.Estimated LV muscle mass (Deveruex) = 117.27g or 71.07 g/m 2 (normal: 43-95 g/m 2 ).2D ejection fraction: 60%.inflammatory cell infiltrate predominantly comprising neutrophils along with few lymphocytes, histiocytes, and few scattered cystic macrophages in the hemorrhagic background.A few small clusters of epithelial cells were seen showing reactive atypia.Overall cytomorphological features are suggestive of an inflammatory lesion.
<0.05 -healthy individuals; <0.5 -low risk of progression to severe systemic sepsis; 0.5-2.0-moderate risk of progression to severe systemic sepsis; 2.00-10.00-high risk of progression to severe systemic sepsis