Background
The investigation and management of patients with an adrenal mass is challenging. There are a wide range of differential diagnoses including, most commonly, a non-functioning adenoma, followed by a functioning adenoma, and more rarely, adrenocortical carcinoma, adrenal metastasis, and infection.1,2
Case Presentation
A 35-year-old male cropping and cattle farmer with no significant past medical history presented to a rural hospital with a three week history of dry cough, small volume haemoptysis and abdominal pain, compounded by a two week history of fevers, drenching night sweats and progressive dyspnoea. He had no significant travel history and no sick contacts. He was a non-smoker, with moderate alcohol intake and denied intravenous drug use.
Initial investigations demonstrated an elevated white cell count (WCC) with a neutrophilia and monocytosis, and a C-reactive protein (CRP) of 144mg/L (<3.0). Computed tomography (CT) imaging of the chest and abdomen identified a cavitating right upper lobe lung lesion and left adrenal lesion, reported to be concerning for adrenal carcinoma (figure 1). Community-acquired pneumonia was presumed, and he was admitted for treatment as such, initially with intravenous (IV) ceftriaxone and IV amoxicillin, followed by IV benzylpenicillin and oral doxycycline, then de-escalated to oral amoxicillin-clavulanate ongoing.
The adrenal lesion was investigated further with FDG-positron emission tomography (PET)/CT. This demonstrated intense heterogeneous avidity within the markedly enlarged left adrenal gland with features concerning for carcinoma and milder avidity within the cavitating lung lesion (figure 2). Attempted CT-guided lung biopsy was unsuccessful. He was discharged on day 9 with a plan for repeat outpatient CT-guided lung biopsy and follow up in the Surgical and Endocrinology Outpatient Clinics.
Adrenal functional studies returned with an equivocal 1mg dexamethasone suppression test and mildly elevated late-night salivary cortisol, with the remainder appearing within normal limits (table 1).
Upon discharge, he deteriorated with worsening abdominal pain and high-grade fevers up to 39.8 degrees Celsius with associated rigors. He was re-admitted within two days and found to have a rising WCC and CRP of 178mg/L (<3.0). He received a single dose of IV ceftriaxone in the Emergency Department and underwent repeat abdominal CT, demonstrating interval enlargement of the left adrenal lesion and development of a left renal vein thrombus (figure 3). Blood cultures were collected and later returned negative. He underwent transthoracic echocardiogram which was negative for valvular vegetations. During this period his analgesic agents were gradually escalated to provide adequate pain relief. He was stabilised and discharged home to await a planned open left adrenalectomy +/- left nephrectomy and splenectomy.
The following day he presented to a tertiary hospital with severe abdominal pain and ongoing fevers. On arrival his WCC was elevated and CRP 282mg/L (<5), and he was admitted under a surgical team for empirical IV piperacillin-tazobactam and monitoring. A repeat infective screen was performed including blood cultures, urine culture and a Covid-PCR swab. He reported progressively severe pain requiring stepwise escalation of multimodal analgesia including oxycodone, ketamine and clonidine.
Fevers continued despite IV piperacillin-tazobactam for 48 hours. He was reviewed by the Infectious Diseases and Respiratory teams with differential diagnoses including metastatic adrenal carcinoma, atypical pneumonia and tuberculosis.
On day 6 of this admission he underwent bronchoscopy and lavage, and an open left adrenalectomy. The latter procedure revealed a central abscess cavity containing thick yellow pus, adherent to the left renal vein with no invasion, without splenic pathology or free pus in the peritoneum. Blood cultures returned positive on the day of surgery, revealing gram positive rods, and raising the question of Nocardia. Antibiotic therapy was changed to IV meropenem and IV sulfamethoxazole-trimethoprim.
On day 2 post-operatively Nocardia cyriacigeorgica was confirmed in blood cultures with preliminary sensitivities to amoxicillin-clavulanate and amikacin. His treatment was refined to IV amoxicillin-clavulanate 1.2g three times daily, along with continued sulfamethoxazole-trimethoprim. Microbiology from bronchoscopy lavage and adrenal sample subsequently also identified Nocardia cyriacigeorgica. After final sensitivities returned his antibiotic therapy was tailored to IV ceftriaxone 2g daily for three weeks and oral sulfamethoxazole-trimethoprim 1600/320mg four times daily for six months. Subsequent blood cultures were negative.
He underwent immunodeficiency screening, which returned unremarkable. His main risk factor for this unusual infection was deemed to be his occupation. He was discharged on day 10 post-operatively with the hospital in the home service and has remained well.
Literature Review
Norcardia is a genus of aerobic gram positive acid-fast bacteria that live ubiquitously throughout the world, found in soil, fresh-water and marine-water.3,4,5,6 Over eighty species have been identified and more than half have been shown to cause human infection with entry via lungs and skin.3,5,6 Pulmonary nocardiosis is reported as the most common site of primary infection.5 Nocardia is thought to disseminate into distant organs via the bloodstream, most commonly affecting the brain, kidney, joints, bone and eyes.3 Adrenal nocardia has only been documented in case reports. Nocardia infection is more common in immunocompromised hosts, however, has been found in immunocompetent individuals.3,4,5,6 The most common risk factors described are immunosuppression and malnutrition.1,2
Clinical presentations vary depending on the site of infection. Adrenal nocardia most commonly presents with fevers and abdominal pain on the side of the affected adrenal gland.1 Diagnosis requires isolation and identification of the organism from a clinical sample and is often delayed due to the specific culture medium required and slow growth which can take up to 3 weeks.7
Consensus recommendations for treatment of disseminated nocardiosis are based on observational studies. There is large diversity in antimicrobial susceptibility among species therefore combination treatment is often used whilst susceptibility testing is performed to guide directed treatment.5 Australian guidelines recommend using trimethoprim-sulfamethoxazole alone for mild disease, adding ceftriaxone for moderate disease, and linezolid with amikacin, imipenem or meropenem for severe disease.8 The rates of trimethoprim-sulfamethoxazole resistance appear low in Australia.5 There is no consensus as to whether performing adjunctive adrenalectomy or laparoscopic drainage of the adrenal gland is beneficial.1 Without appropriate treatment of disseminated nocardia, studies suggest a high mortality rate of 30-50 percent, which can be even higher in individuals with cerebral involvement.1,4,5
The work up and management of this patient was staggered across three admissions and two health services, after his presentation with this myriad of symptoms that raised concern for both a malignant and infective process. An adrenal lesion typically permits outpatient work up and management, but the diagnosis on this occasion warranted more intense inpatient work up. Surgery was deemed necessary given his clinical state, but consideration of this diagnosis in future patients may potentially avoid an invasive procedure.
Take Home Messages