Destructive Cryptococcal Osteomyelitis Mimicking Tuberculous Spondylitis

Abstract

BACKGROUND Cryptococcosis is an opportunistic fungal infection that typically occurs in patients with compromised immune systems, primarily affecting the respiratory and central nervous systems. However, cryptococcal osteomyelitis is a rare manifestation of cryptococcal infection, characterized by nonspecific clinical features. Here, we present a case of vertebral cryptococcal osteomyelitis in a middle-aged woman and discuss diagnostic approaches. CASE REPORT A 56-year-old woman presented with lower back pain and limited mobility, without fever, and with a history of pulmonary tuberculosis. Physical examination revealed enlarged lymph nodes and tenderness in the thoracic vertebrae. A computed tomography-guided biopsy confirmed granulomatous inflammation caused by Cryptococcus, with abundant 10 μm spherical microbial spores. After 4 weeks of treatment with amphotericin B and fluconazole, symptoms and lesions improved. Upon discharge, the patient was prescribed oral fluconazole. Follow-up examinations showed a stable condition and a negative serum cryptococcal capsular polysaccharide antigen test. CONCLUSIONS Given the rarity and lack of specificity of clinical features of cryptococcal spondylitis, clinicians encountering similar presentations should consider tuberculous spondylitis and spinal tumors as differential diagnoses. Additionally, tissue biopsy of the affected vertebral bodies should be performed early to establish the type of vertebral infection, aiding in diagnosis, treatment, and prognosis.

Figure 1.

Chest computed tomography. (A, B) Old tuberculosis in the right upper lung, Bilateral lower lobe pulmonary infiltrates with a small amount of pleural effusion (on admission).

Figure 2.

Posttherapy magnetic resonance imaging (MRI). Thoracic spine computed tomography (A) and MRI sagittal T1- and T2-weighted images (B, C) show T10 vertebral compression fracture (upon admission). (D) the sagittal T2-weighted of MRI after 1 month of antifungal treatment. (E) the sagittal T2-weighted of MRI after 3 months of antifungal treatment.

Figure 3.

Single photon emission computed tomography (SPECT) shows increased uptake of technetium-99m in the area of T10 vertebra and the right humerus.

Figure 4.

Puncture biopsy-sample with hematoxylin and eosin staining of the right axillary lymph node tissue suggests granulomatous inflammation.

Figure 5.

Computed tomography-guided needle biopsy for lesion at thoracic T10 vertebrae with staining method. (A) Hematoxylin and eosin stain reveals the granulomatous inflammation with histiocytes, multinucleated giant cells and leukomonocyte. (B) Acid-fast staining reveals acid-fast negative yeast cells. (C) Mucicarmine silver stain shows yeast-like organisms with a thick mucinous wall as highlighted (arrow). (D) Periodic acid-Schiff (PAS) stain reveals several 10 μm diameter PAS-positive spherules with prominent capsules. Magnification ×400.