INTRODUCTION:Botryomycosis is an uncommon bacterial disease that clinically and histologically mimics infection by actinomyces species. The granules of botryomycosis resemble the 'sulphur granules' of actinomycosis. A total of 16 cases of bronchopulmonary botryomycosis have been reported in English literature so far, 13 of them had an underlying disease. We describe a case of primary pulmonary botryomycosis in an immuno-competent patient, whose clinical course mimicked actinomycosis(1,2).
CASE PRESENTATION: A 47-yr-old gentleman, a non smoker, a sewage worker, without any chronic medical illness presented with chief complaints of fever of 2 months duration,productive cough since 1½ months,pain left lateral chest and breathlessness of 15 days duration each. History of anorexia and undocumented weight loss were present. Physical examination revealed a well built man with stable vital signs except a temperature of 101 degree F. Head to toe examination was unremarkable. Chest examination demonstrated decreased intensity of breath sounds with inspiratory crepitations over left infra-mammary, infra-axillary and infra-scapular regions. Thoracic imaging [chest X ray and computerized tomography (CT)] revealed consolidation in left lower lobe. Laboratory examination revealed a total leucocyte count of 17,500 cells/mm3, a differential count of polymorphs 81%, lymphocytes 13%, eosinophils and monocytes of 3% each. Results of blood sugar, renal and liver function studies were within normal range. HIV serology was negative. Sputum for Acid Fast Bacilli (AFB), fungus and pyogenic organisms were negative. Sputum for cytology revealed acute inflammatory expectorates comprising predominantly neutrophils. Bronchial aspirate showed acute neutrophilic infiltrate with bacterial colonies but was negative for pyogenic organisms, AFB, fungi and malignant cytology. Trans-bronchial lung biopsy (TBLB) demonstrated necrotic alveoli and “sulphur” granules (Graphic 1). The patient was diagnosed as a case of actinomycosis and put on benzyl pencillin. Two weeks later there was no relief, clinically or radiologically. All the tests were repeated including bronchoscopy and TBLB; All the results were the same. The Periodic acid schiff (PAS) stain was also negative. Further gram staining evaluation revealed gram positive bacteria which were non-filamentous and non-branching and morphologically resembled Staphylococcus (Graphic 2). The culture was again negative for pyogenic organisms. The patient was then started on amoxicillin and clavulanic acid 625mg thrice a day for 15 days (1). Thoracic imaging was repeated after 15 days which showed complete clearance of the lesion. The patient was discharged from the hospital in a stable condition.
DISCUSSIONS: The presence of gram positive cocci, absence of branching hyphae, negative PAS and AFB staining helped to clinch the diagnosis in our patient.Botryomycosis is a rare, chronic, suppurative, sometimes granulomatous infection of the skin (75%), soft tissues and viscera (25%). Patients with primary pulmonary botryomycosis and actinomycosis can present similarly. Both infections may display sulphur granules. When the sulphur granules are cultured, common organisms like Staphylococcus aureus (most common), Pseudomonas aeruginosa, Escherichia coli etc. are recovered. In botryomycisis cultures may be negative for pyogenic organisms (1,2). This disease is usually described in patients with underlying disease such as diabetes mellitus, cystic fibrosis or HIV infection (1,2). The uniqueness of our case is that botryomycosis occurred in an immunocompetent person.
CONCLUSION: This case emphasizes the need for increased physician awareness of this unusual bacterial infection that may mimic actinomycosis both clinically and pathologically, and should be considered in the differential diagnosis for patients who present with a clinical picture of indolent pulmonary actinomycosis.
DISCLOSURE: Pankaj Sayal, None.