Unusual suspects: pulmonary opportunistic infections masquerading as tumor metastasis in a patient with adrenocorticotropic hormone-producing pancreatic neuroendocrine cancer

Pneumocystis pneumonia in patients with Cushing's syndrome: A French multicenter retrospective study

OBJECTIVE

Pneumocystis pneumonia (PcP) is an opportunistic infection occurring in immunocompromised patients. Cushing's syndrome (CS) impairs the immune system, and several authors have reported PcP in patients with CS. The present study aimed to characterize PcP occurring in a CS context and its management in French tertiary centers, in order to highlight the similarities in clinical presentation and treatment according to whether prophylaxis is implemented or not.

METHODS

This was a multicenter retrospective study conducted in several French University Hospitals and Cancer Centers. Patients with PcP and confirmed CS regardless of etiology were included. We excluded patients with other known causes of acquired immunodeficiency with increased risk of PcP.

RESULTS

Twenty-five patients were included. CS etiology was neoplastic in 84.0% of cases. CS clinical presentation associated predominant catabolic signs (76.0%), hypokalemia (91.7%) and lymphopenia (89.5%). CS was intense in most patients, with mean plasma cortisol levels at diagnosis of 2.424±1.102nmol/L and urinary free cortisol>10× the upper limit of normal in 85.0%. In all patients, PcP onset followed introduction of cortisol blockers, at a median 5.5 days. Patients were treated with 1 to 3 cortisol blockers, mainly metyrapone (88%), which significatively lowered plasma cortisol levels to 667±541nmol/L at the onset of PcP (P<0.001). PcP occurred in 7 patients despite prophylaxis. Finally, 60.0% patients were admitted to intensive care, and 20.0% died of PcP.

CONCLUSION

High mortality in patients with PcP implies that clinicians should be better informed about this rare infectious complication. Prophylaxis remains controversial, requiring comparative studies.

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

OBJECTIVE

To analyze and summarize the clinical characteristics, treatments, and prognosis of Cushing's syndrome (CS) with nocardiosis.

METHODS

A patient in our hospital and additional 17 patients of CS with nocardiosis in the English literature were included in this study. Clinical characteristics, laboratory data, imaging studies, treatments, and prognosis were evaluated.

RESULTS

A 41-year-old man with CS was diagnosed and treated in our hospital. He had co-infections of nocardiosis and aspergillosis. Together with 17 patients of CS with nocardiosis in the English literature, 2 patients (11.1%) were diagnosed as Cushing's disease (CD) while 16 (88.9%) were diagnosed or suspected as ectopic ACTH syndrome (EAS). The average 24hrUFC was 7,587.1 ± 2,772.0 μg/d. The average serum total cortisol and ACTH (8 AM) was 80.2 ± 18.7 μg/dl and 441.8 ± 131.8 pg/ml, respectively. The most common pulmonary radiologic findings in CT scan were cavitary lesions (10/18) and nodules (8/18). Co-infections were found in 33.3% (6/18) patients. The CS patients with co-infections had higher levels of ACTH (671.5 ± 398.2 vs 245.5 ± 217.1 pg/ml, P = 0.047), and 38.9% (7/18) patients survived through the antibiotic therapy and the treatment of CS. Patients with lower level of ACTH (survival vs mortality: 213.1 ± 159.0 vs 554.7 ± 401.0 pg/ml, P = 0.04), no co-infection, underwent CS surgery, and received antibiotic therapy for more than 6 months, had more possibilities to survive.

CONCLUSIONS

Nocardia infection should be cautioned when a patient of CS presented with abnormal chest radiographs. The mortality risk factors for CS with nocardiosis are high level of ACTH and co-infections. We should endeavor to make early etiological diagnosis, apply long-term sensitive antibiotics and aggressive treatments of CS.

Pneumocystis pneumonia can complicate medical treatment of hypercortisolism even in outpatients with Cushing's disease

Several cases of Pneumocystosis pneumonia (PCP) have been reported in patients with hypercortisolism, mainly in patients with severe ectopic ACTH syndrome (EAS). We report 2 cases of PCP that did not develop until after starting treatment with metyrapone, one of which occurred in an outpatient with Cushing's disease (CD) without pulmonary symptoms before medical treatment for CD. Patient 1 presented as an outpatient with CD and severe hypercortisolism but nonetheless in good general condition. Treatment with metyrapone was started before pituitary surgery. Patient 2 had EAS due to prostate cancer. Respiratory failure in the two patients occurred 4 days and 30 days, respectively, after the start of metyrapone treatment. In both cases, chest CT showed bilateral interstitial infiltrates, and Pneumocystis jirovecii was found on bronchoalveolar lavage (BAL). A literature review was performed to identify risk factors for PCP in patients with CD: we identified 20 other cases of PCP in patients treated for hypercortisolism, including 16 patients with EAS. Ninety percent of patients had free urinary cortisol greater than 6 times the upper limit of normal (ULN). In conclusion, onset of PCP after initiation of anticortisolic therapy is not limited to patients with EAS, and may occur in CD patients with elevated cortisol levels, even if the patient remains in good general condition and has no pulmonary symptoms before treatment. In such patients, routine prophylactic treatment with trimethoprim/sulfamethoxazole (TMP/SMX) should be considered.

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.

An Elderly Man With Pancreatic Neuroendocrine Tumor and a Cavitary Right Upper Lobe Lung Mass

CASE PRESENTATION

An elderly man presented to the ED from a nursing care facility after transient loss of consciousness. Three weeks previously, the patient had been diagnosed with a high-grade pancreatic neuroendocrine tumor (NET) with metastases to the liver after being hospitalized for weakness. A chest radiograph at that time had revealed a right upper lobe mass that was presumed to represent a metastatic lesion (Fig 1); CT of the chest demonstrated similar findings (Fig 2). The patient had recovered consciousness on arrival to the ED and was diagnosed clinically as having had a syncopal episode from dehydration due to poor intake. On review of systems, the patient reported shortness of breath and a cough productive of scant mucoid sputum of 1 week's duration. He had no complaints of fever but complained of weakness and poor appetite. In addition, his medical history was significant for hypertension, diabetes mellitus, and congestive heart failure with systolic dysfunction. He was a former smoker. Prior to his recent illness and hospitalization, he lived at home with his family and was independent in his activities of daily living.

Characteristics and Mortality of Pneumocystis Pneumonia in Patients With Cushing's Syndrome: A Plea for Timely Initiation of Chemoprophylaxis

In patients with Cushing's syndrome, development of Pneumocystis pneumonia (PCP) is associated with extreme cortisol production levels. In this setting, immune reconstitution after abrogation of cortisol excess appears to induce development of symptomatic PCP. The high mortality rate warrants timely initiation of chemoprophylaxis or even preemptive treatment of PCP.

Pneumocystis Pneumonia Concomitant with Ectopic ACTH Syndrome Caused by a Large Cell Neuroendocrine Carcinoma of the Thymus

We herein report the case of a 44-year-old man who was diagnosed with pneumocystis pneumonia (PCP) concomitant with ectopic adrenocorticotropic hormone (ACTH) syndrome, which had been caused by a large cell neuroendocrine carcinoma of the thymus. Chest computed tomography revealed ground-glass opacities in the lungs. PCP was diagnosed by a polymerase chain reaction with bronchoalveolar lavage. The levels of cortisol were slowly corrected with an adrenal enzyme inhibitor, and the exacerbation of PCP was successfully avoided. Our case indicates that in addition to prophylaxis, the early diagnosis of PCP and the slow correction of hypercortisolemia should be considered in order to prevent an exacerbation due to the reconstitution of the immune function in patients with ectopic ACTH syndrome.

Nocardiosis in ectopic ACTH syndrome: A case report and review of 11 cases from the literature

Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) associated with nocardiosis is rare, and little information is available regarding its clinical characteristics. In this study, the case of a 35-year-old male patient who showed significant cushingoid features and had a cough with yellow phlegm for 1 month is described. Pulmonary computed tomography (CT) scanning and ¹⁸F-fluorodeoxyglucose positron emission tomography combined with CT identified two different lesions in the mediastinum and pulmonary region, respectively. The lesion in the mediastinum was finally diagnosed as an ACTH-secreting mediastinal paraganglioma via biopsy. The sputum culture confirmed pulmonary nocardiosis. The patient was effectively treated with complete tumor resection following the treatment of nocardiosis using trimethoprim-sulfamethoxazole. Following the present case, 11 additional cases of nocardiosis in EAS were identified in the literature and their clinical characteristics were compared and evaluated. It may be concluded that, although Nocardia remains a rare opportunistic infection pathogen in EAS, it is necessary to consider nocardiosis as a diagnosis for patients with pulmonary imaging findings of cavity, consolidation or nodule, particularly when there are brain and extra-pulmonary lesions as well as a poor response to regular treatment.