Cushing's Syndrome With Nocardiosis: A Case Report and a Systematic Review of the Literature

Differentiating lung neuroendocrine neoplasms from tumor-like infection using CT in patients with ectopic ACTH syndrome

OBJECTIVES

Pulmonary neuroendocrine neoplasms (NENs) are the most frequent cause of ectopic adrenocorticotropic hormone syndrome (EAS); lung infection is common in EAS. An imaging finding of infection in EAS patients can mimic NENs. This retrospective study investigated EAS-associated pulmonary imaging indicators.

METHODS

Forty-five pulmonary NENs and 27 tumor-like infections from 59 EAS patients (45 NEN and 14 infection patients) were included. Clinical manifestations, CT features, 18F-FDG, or 68Ga-DOTATATE-PET/CT images and pathological results were collected.

RESULTS

High-sensitivity C-reactive protein (p < 0.001) and expectoration occurrence (p = 0.04) were higher, and finger oxygen saturation (p = 0.01) was lower in the infection group than the NENs group. Higher-grade NENs were underrepresented in our cohort. Pulmonary NENs were solitary primary tumors, 80% of which were peripheral tumors. Overlying vessel sign and airway involvement were more frequent in the NENs group (p < 0.001). Multifocal (p = 0.001) and peripheral (p = 0.02) lesions, cavity (p < 0.001), spiculation (p = 0.01), pleural retraction (p < 0.001), connection to pulmonary veins (p = 0.02), and distal atelectasis or inflammatory exudation (p = 0.001) were more frequent in the infection group. The median CT value increment between the non-contrast and arterial phases was significantly higher in NENs lesions (p < 0.001). Receiver operating characteristic curve analysis indicated a moderate predictive ability at 48.3 HU of delta CT value (sensitivity, 95.0%; specificity, 54.1%).

CONCLUSION

Chest CT scans are valuable for localizing and characterizing pulmonary lesions in rare EAS, thereby enabling prompt differential diagnosis and treatment. CRITICAL RELEVANCE STATEMENT: Thin-slice CT images are valuable for the localization and identification of pulmonary ectopic adrenocorticotropic hormone syndrome lesions, leading to prompt differential diagnosis and effective treatment.

KEY POINTS

Lung tumor-like infections can mimic neuroendocrine neoplasms (NENs) in ectopic adrenocorticotropic hormone syndrome (EAS) patients. NENs are solitary lesions, whereas infections are multiple peripheral pseudotumors each with identifying imaging findings. Typical CT signs aid in localization and creating an appropriate differential diagnosis.

Nocardia Infection in Nephrotic Syndrome Patients: Three Case Studies and A Systematic Literature Review

Objective

The multicenter literature review and case studies of 3 patients were undertaken to provide an updated understanding of nocardiosis, an opportunistic bacterial infection affecting immunosuppressed nephrotic syndrome (NS) patients receiving long-term glucocorticoid and immunosuppressant treatment. The results provided clinical and microbiological data to assist physicians in managing nocardiosis patients.

Methods

Three cases between 2017 and 2018 from a single center were reported. Additionally, a systematic review of multicenter cases described in the NCBI PubMed, Web of Science, and Embase in English between January 1, 2001 and May 10, 2021 was conducted.

Results

This study described three cases of Nocardia infection in NS patients. The systematic literature review identified 24 cases with sufficient individual patient data. A total of 27 cases extracted from the literature review showed that most patients were > 50 years of age and 70.4% were male. Furthermore, the glucocorticoid or corticosteroid mean dose was 30.9 ± 13.7 mg per day. The average time between hormone therapy and Nocardia infection was 8.5 ± 9.7 months. Pulmonary (85.2%) and skin (44.4%) infections were the most common manifestations in NS patients, with disseminated infections in 77.8% of patients. Nodule/masses and consolidations were the major radiological manifestations. Most patients showed elevated inflammatory biomarkers levels, including white blood cell counts, neutrophils percentage, and C-reactive protein. Twenty-five patients received trimethoprim-sulfamethoxazole monotherapy (18.5%) or trimethoprim-sulfamethoxazole-based multidrug therapy (74.1%), and the remaining two patients (7.4%) received biapenem monotherapy. All patients, except the two who were lost to follow-up, survived without relapse after antibiotic therapy.

Conclusions

Nephrotic syndrome patients are at high risk of Nocardia infection even if receiving low-dose glucocorticoid during the maintenance therapy. The most common manifestations of nocardiosis in NS patients include abnormal lungs revealing nodules and consolidations, skin and subcutaneous abscesses. The NS patients have a high rate of disseminated and cutaneous infections but a low mortality rate. Accurate and prompt microbiological diagnosis is critical for early treatment, besides the combination of appropriate antibiotic therapy and surgical drainage when needed for an improved prognosis.

Use of Continuous Etomidate Infusion to Rapidly Correct Hypercortisolism in a Patient With Disseminated Nocardiosis

Cushing’s syndrome (CS) is an immunocompromised state characterized by impaired cellular and adaptive immunity due to hypercortisolism. This imbalance in the immune system leads to a high risk of opportunistic infections which can potentially prove fatal. In such patients, mortality can be reduced with early diagnosis and effective management of the underlying hypercortisolism. In this case report, we describe how prompt reduction of cortisol levels using a low dose continuous etomidate infusion was pivotal in effective treatment of an opportunistic infection, disseminated nocardiosis, in a 29-year-old female with Cushing’s syndrome. We also discuss how treatment with antibiotics including empiric therapy with Imipenem and sulfamethoxazole/trimethoprim (SMX/TMP) and definite therapy as per susceptibility testing, with amikacin, SMX/TMP, and doxycycline helped to prevent adverse outcomes. Through this case, we aim to emphasize that infiltrates or cavitary lesions on the computed tomography (CT) scan of the chest in a patient with Cushing’s syndrome should raise concern for nocardiosis, and prompt management with antibiotics should be initiated. Similarly, disseminated nocardiosis should always raise concern for possible immune deficiency states like Cushing’s syndrome. Our case is unique in detailing the significance of using etomidate to acutely lower cortisol levels in a patient with endogenous CS and widespread invasive opportunistic infection. The pharmacology aspects of the Etomidate, in this case, have been published in the Journal of Pharmacy Practice and cited appropriately in this article.