Current perspective of adrenal histoplasmosis in India: A prospective study in a tertiary care hospital, Eastern India

PURPOSE

Adrenal histoplasmosis (AH) is an uncommon form of disseminated histoplasmosis caused by the dimorphic fungus Histoplasma capsulatum. Though, India is considered to be a non-endemic area for histoplasmosis, a high rise of AH cases is reported currently from various parts of India. Our study aimed to evaluate the current perspective of adrenal histoplasmosis in India by reviewing its clinical course, differential diagnosis, treatment, and mortality of our eleven confirmed cases of AH along with the review of authentic reported AH cases from India.

MATERIAL &METHOD

Clinical materials were taken from radiologically suspected all 15 cases either with unilateral or bilateral adrenal enlargement, referred between 2018 and 2020 for microbiological investigations. Fungal stain and fungal culture along with other tests for possible differential diagnosis with AH were conducted.

RESULT

Out of fifteen incidentaloma detected by radio-imaging, eleven cases of AH had been diagnosed in our hospital with yield of Rhodotorula spp. in one mimicking case. Nine of them were male (82%) and all were HIV nonreactive, which corroborates with the literature review. All of them had nonspecific clinical presentation of chronic abdominal pain, fever, weight loss, and anorexia. Four developed primary adrenal insufficiency, which are similar to the literature review (41%). On treatment with itraconazole and/or amphotericin B, all patients survived except one lost in follow-up.

CONCLUSION

Male preponderance and non-compromised immune status are two special characteristics of most AH though reasons are ill understood. So, mycological investigations are to be done for every such case.

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.

18F-FDG PET/CT imaging and PET-guided biopsy in evaluation and treatment decision in adrenal histoplasmosis

Histoplasmosis is a rare opportunistic fungal infection. It is commonly seen in immunocompromised individuals from endemic areas. Adrenal glands are frequently involved in the disseminated disease. Here, we present the case of a retropositive patient with constitutional symptoms, where whole-body positron emission tomography/CT scan revealed intense ¹⁸F-fludeoxyglucose uptake in bulky adrenal glands, and subsequent positron emission tomography-guided biopsy helped in establishing the diagnosis of adrenal histoplasmosis.

18F-FDG PET as a monitoring tool to assess treatment response in bilateral adrenal histoplasmosis

A 60-year-old woman with clinical and biochemical features suggestive of adrenal insufficiency was found to have bilateral adrenal masses on CT scan and was subjected to F-FDG PET scan. The scan showed hypermetabolic mediastinal nodes in addition to intense tracer uptake in bilateral adrenal masses. CT-guided adrenal biopsy grew Histoplasma capsulatum on Sabouraud dextrose agar culture. A second F-FDG PET scan after 6 months of appropriate antifungal therapy showed a significant decrease in intensity of uptake consistent with the clinical outcome.

Pseudometastasis secondary to histoplasmosis infection: false-positive PET/CT findings

Positron emission computed tomography (PET)/CT is a common modality used in the workup of neoplastic conditions. However, false-positive results may be produced by underlying infectious processes. We report two cases of false-positive PET/CT studies secondary to histoplasmosis infections in both a pediatric and a young adult patient. After the diagnoses, one patient was observed with no therapy and the other received a complete course of itraconazole. In both cases biopsy results were positive for fungal elements consistent with histoplasmosis. Both patients were successfully managed and have had follow-up histoplasmosis titers that reveal resolving infections.