Summary:
Cryptococcal osteomyelitis
IMAGING FINDINGS
Radiography of the thoracic spine demonstrated compression
fracture of T6 (Figure 1). CT demonstrated a paravertebral
soft-tissue mass with destruction of T6 vertebral bodies, posterior
elements, and posterior left rib (Figure 2). MR imaging revealed
abnor
Diagnosis
Cryptococcal osteomyelitis
Findings
IMAGING FINDINGS
Radiography of the thoracic spine demonstrated compression
fracture of T6 (Figure 1). CT demonstrated a paravertebral
soft-tissue mass with destruction of T6 vertebral bodies, posterior
elements, and posterior left rib (Figure 2). MR imaging revealed
abnormal enhancement within the T6 vertebral body with sparing of
the adjacent intervertebral discs (Figure 3).
Discussion
Cryptococcus neoformans is a ubiquitous yeast (Figure 4)
that grows abundantly in soil containing bird (especially pigeon)
droppings. Disseminated infection of man and animals occurs mainly
in the immunocompromised, with the lungs and central nervous system
most commonly affected. Approximately 50% of patients with
cryptococcal meningitis, however, show no evidence of
immunosuppression. Osteomyelitis occurs in 5% to 10% of
disseminated cases, but isolated bone involvement is rare.
Crypto-coccal meningitis is common in HIV-infected patients;
however, no case of cryptococcal osteomyelitis has been reported in
this population.
A recent review of 40 reported cases found most cases involved
one site. The most common site was the spine, followed by the
femur, tibia, humerus, and ribs. The most common comorbidity was
sarcoidosis, followed by tuberculosis, steroid therapy, and, as in
this case, diabetes mellitus.
Differential diagnostic considerations include tuberculosis,
plasmacytoma, metastatic disease, and lymphoma.
Prepared by Timothy C. Sloan, DVM, MD, a
Radiologist at Coastal Radiology, New Bern, SC and Jason
Hosey, MD, a Resident of Diagnostic Radiology at The
Medical University of South Carolina, Charleston, SC.
1. Liu PY. Cryptococcal osteomyelitis: Case report and review.
Diagn Microbiol Infect Dis. 1998;30:33-35.
2. Resnick D. Cryptococcosis (torulosis). In: Diagnosis of
Bone and Joint Disorders. 3rd ed. Philadelphia, PA: WB
Saunders; 1995:2505-2506.