Imaging findings of cryptococcal infection of the thoracic spine

Isolated cryptococcal osteomyelitis of the sacrum in an immunocompetent patient: a case report and literature review

BACKGROUND

Cryptococcus neoformans, an opportunistic fungal pathogen, seldom causes infection in immunocompetent people. Cryptococcal osteomyelitis is an uncommon condition in which Cryptococcus invades the bone. It usually occurs as part of a disseminated infection and rarely in isolation. The spine has been reported as the most common site of cryptococcal osteomyelitis; however, isolated case of sacrum involvement in immunocompetent patients has never been reported.

CASE PRESENTATION

We report the case of a 37-year-old man without underlying disease who presented with progressive low back and sacrococcygeal pain. The patient was initially diagnosed with sacral tumour by a local doctor, and subsequently, after admission, was diagnosed with sacral tuberculosis. He was empirically treated with antitubercular drugs. The patient failed to respond to antitubercular drugs and complained of worsening low back pain. Additionally, he developed persistent radiating pain and numbness in his legs. For further diagnosis, we performed a computed tomography-guided puncture biopsy of the sacrum, which revealed granulomatous inflammation with massive macrophage infiltration and special staining revealed a fungal infection. We performed sacral debridement and drainage and obtained purulent specimens for pathological examination and microbial culture. Microbial identification and drug susceptibility tests revealed a Cryptococcus neoformans infection sensitive to fluconazole. Postoperatively, the persistent radiating pain and numbness in the legs resolved. After 12 consecutive weeks of antifungal therapy, all his symptoms resolved. The patient remained without any signs of recurrence at the 8-month follow-up.

CONCLUSION

We reported a rare case of isolated sacrum cryptococcal osteomyelitis in an immunocompetent patient. Furthermore, we identified and reviewed 18 published cases of spine cryptococcal osteomyelitis. Immunocompetent individuals are also at risk for cryptococcal osteomyelitis. Clinical manifestation and imaging are insufficient to diagnose cryptococcal osteomyelitis of the spine, and invasive examinations, such as puncture biopsy and fungal examinations, are needed. Antifungal therapy yields satisfactory results for the treatment of cryptococcal osteomyelitis of the spine, however, if the infective lesion is large, especially when it compresses the spinal cord and nerves, a regimen combining aggressive surgery with antifungal therapy is indispensable.

Isolated cryptococcosis of a lumbar vertebra in an immunocompetent patient: A case report and literature review

Background

Cryptococcus, a kind of fungus, can be found in soil, decayed wood, and avian excreta. Immunocompromised patients are prone to infection caused by Cryptococcus, and the lungs and central nervous system are the main target organs. Cryptococcosis rarely occurs in the lumbar vertebra or in immunocompetent patients.

Case presentation

A 40-year-old adult male with isolated lumbar vertebra cryptococcosis at the L4 vertebra underwent successful lesion removal surgery performed via the posterior approach and postoperative administration of an antifungal agent. At the 12-month follow-up, the patient's pain was relieved, and his motor function had improved. Isolated Cryptococcus vertebrae infection is a rare infectious disease.

Conclusions

A needle biopsy can confirm the diagnosis of Cryptococcus infection. When patients present with unbearable symptoms of nerve compression, posterior depuration combined with postoperative antifungal agents is a good option.

Case Report: A Case of Severe Cryptococcal Immune Reconstitution Inflammatory Syndrome Presenting with Brain and Intradural Abscesses in an HIV Patient

Clinical worsening or new manifestation of cryptococcal disease following initiation of anti-retroviral therapy (ART) in an HIV patient is a hallmark of cryptococcal immune reconstitution inflammatory syndrome (C-IRIS). However, it can be difficult to distinguish IRIS from worsening or new infection. Here, we present a case of severe C-IRIS involving multiple cerebellar, spinal, and intradural abscesses and spinal arachnoiditis 7 months after ART initiation in an AIDS patient with uncertain prior ART compliance. He had multiple prior episodes of cryptococcal meningitis with complications necessitating ventriculoperitoneal shunt placement and was on suppressive fluconazole when he developed worsening brain manifestations. He received empiric anti-cryptococcal re-induction without improvement. All cerebrospinal fluid cultures remained sterile, with negative Cryptococcus PCR testing, and his condition continued to worsen prior to corticosteroid initiation. Ultimately, C-IRIS was diagnosed by brain biopsy. This case demonstrates an extreme in severity of C-IRIS and in the timeline of presentation after ART initiation.

Disseminated Cryptococcosis revealed by transverse myelitis in Immunocompetent patient: a case report and review of the literature

Background

Transverse myelitis (TM) is due to inflammatory spinal cord injury with bilateral neurologic involvement, which is sensory, motor, or autonomic in nature. It may be associated with autoimmune disease, vaccination, intoxication and infections. The most common infection cause of TM is Coxsackie virus and Mycoplasma pneumoniae. The cryptococcosis is rare. We present the case of disseminated cryptococcosis revealed by transverse myelitis in an immunocompetent 55-year-old male patient. The literature review is also stated.

Case presentation

The 55-year-old man suffered from gradual numbness, weakness in both lower limbs and finally paralyzed in the bed. The thoracic spine Computed tomography (CT) was normal, but multiple nodules in the lung were accidentally discovered. Thoracic Magnetic Resonance Imaging (MRI) showed diffused thoracic spinal cord thickening and extensively intramedullary T2 hyper intensity areas. Gadolinium contrast enhanced T1WI showed an intramedullary circle-enhanced nodule at 9th thoracic level. Diagnosis was made by histological examination of the bilateral lung biopsy. The patient was treated successfully with systemic amphotericin B liposome and fluconazole and intrathecal dexamethasone and amphotericin B liposome.

Conclusions

This is a patient with disseminated cryptococcosis involving the lung, spinal cord and adrenal glands, which is rare in the absence of immunodeficiency.

Thoracic cryptococcal osteomyelitis mimicking tuberculosis: A case report

Background:

Isolated cryptococcal osteomyelitis of the spine is extremely uncommon; there have been only seven cases identified in literature. The majority were originally misdiagnosed as tuberculosis. Here, we present a patient with cryptococcal osteomyelitis of the thoracic spine with associated fungal retinal deposits.

Case Description:

A 45-year-old, type II diabetic female presented with a 5-month history of severe back pain. Her magnetic resonance imaging (MRI) revealed osteomyelitis involving the T4 vertebral body with epidural and prevertebral extension; notably, the intervertebral disc spaces were not involved. Although the fine-needle aspiration cytologic examination was inconclusive, the patient was empirically placed on antitubercular drug therapy. One month later, she became fully paraplegic. The MRI now demonstrated osteolytic lesions involving the T4 vertebral body with cord compression. She underwent biopsy of the T4 vertebral body and a transfacet T4 decompression with T2-T6 pedicle screw fixation. Culture and histopathological examinations both documented a cryptococcal infection, and she was placed on appropriate antifungal therapy. Notably, 3 weeks after surgery, she developed a sudden loss of vision loss due to retinal fungal endophthalmitis. She recovered vision in one eye after the administration of intravitreal voriconazole but lost vision in the other eye despite a vitrectomy. Over the next 8 months, she gradually recovered with motor function of 4/5 in both lower extremities without evidence of recurrent disease.

Conclusion:

Cryptococcal infection should be among the differential diagnostic considerations for patients with vertebral osteomyelitis. Notably, diagnostic delay can lead to devastating neurological deficits and involvement of other organ systems.

FDG PET/CT imaging in detecting and guiding management of invasive fungal infections: a retrospective comparison to conventional CT imaging

PURPOSE

Invasive fungal infections (IFIs) are common in immunocompromised patients. While early diagnosis can reduce otherwise high morbidity and mortality, conventional CT has suboptimal sensitivity and specificity. Small studies have suggested that the use of FDG PET/CT may improve the ability to detect IFI. The objective of this study was to describe the proven and probable IFIs detected on FDG PET/CT at our centre and compare the performance with that of CT for localization of infection, dissemination and response to therapy.

METHODS

FDG PET/CT reports for adults investigated at Peter MacCallum Cancer Centre were searched using keywords suggestive of fungal infection. Chart review was performed to describe the risk factors, type and location of IFIs, indication for FDG PET/CT, and comparison with CT for the detection of infection, and its dissemination and response to treatment.

RESULTS

Between 2007 and 2017, 45 patients had 48 proven/probable IFIs diagnosed prior to or following FDG PET/CT. Overall 96% had a known malignancy with 78% being haematological. FDG PET/CT located clinically occult infection or dissemination to another organ in 40% and 38% of IFI patients, respectively. Of 40 patients who had both FDG PET/CT and CT, sites of IFI dissemination were detected in 35% and 5%, respectively (p < 0.001). Of 18 patents who had both FDG PET/CT and CT follow-up imaging, there were discordant findings between the two imaging modalities in 11 (61%), in whom normalization of FDG avidity of a lesion suggested resolution of active infection despite a residual lesion on CT.

CONCLUSION

FDG PET/CT was able to localize clinically occult infection and dissemination and was particularly helpful in demonstrating response to antifungal therapy.

What, where and why: exploring fluorodeoxyglucose-PET's ability to localise and differentiate infection from cancer

PURPOSE OF REVIEW

To review the utility of FDG-PET imaging in detecting the cause of fever and infection in patients with cancer.

RECENT FINDINGS

FDG-PET has been shown to have high sensitivity and accuracy for causes of neutropenic fever, leading to higher diagnostic certainty in this group. Recent advances in pathogen-specific labelling in PET to identify Aspergillus spp. and Yersinia spp. infections in mice, as well as differentiating between Gram-positive, Gram-negative and mycobacterial infections are promising.

SUMMARY

Patients with cancer are vulnerable to infection and fever, and the causes of these are frequently unclear using conventional diagnostic methods leading to high morbidity and mortality, length of stay and costs of care. FDG-PET/CT, with its unique complementary functional and anatomical information as well as its whole-body imaging capability, has demonstrated use in detecting occult infection in immunocompromised patients, including invasive fungal and occult bacterial infections, as well as defining extent of infection. By demonstrating disease resolution following treatment and allowing earlier cessation of therapy, FDG-PET acts as a key tool for antimicrobial and antifungal stewardship. Limitations include at times poor differentiation between infection, malignancy and sterile inflammation, however, exciting new technologies specific to infectious pathogens may help alleviate that issue. Further prospective randomised research is needed to explore these benefits in a nonbiased fashion.

Diagnosis and treatment of nonadjacent cryptococcal infections at the L1 and S1 vertebrae

Cryptococcal spine infections are rare infections that are easy to misdiagnose and difficult to cure. Therefore, we report the case of a 25-year-old man who presented with nonspecific spinal lesions at L1 and S1. The patient underwent surgical removal of the lesions, and specimens were submitted for microbial identification, which identified a cryptococcal infection that was susceptible to amphotericin B. The patient exhibited marked improvement after receiving intravenous amphotericin B and remained asymptomatic (no back pain, fever, or other symptoms) at the 3‑ and 9‑month follow-ups. Similar cases of cryptococcal spine infections are rare, and we believe that our diagnostic findings and treatment experience may help improve the management of this rare disease.