Educational Point-of-Care Ultrasound Discovers Adrenal Cortical Carcinoma, a Case Report: Clinical Implications and Review of the Literature

Abstract

Introduction

Point-of-care ultrasound (POCUS) has become an indispensable tool for emergency physicians in assessing intra-abdominal pathology due to its real-time visualization, portability, and cost-effectiveness. While POCUS is not traditionally focused on adrenal gland assessment, incidental findings of adrenal masses during examinations have been reported. Our patient presented with a chronic obstructive pulmonary disease (COPD) exacerbation and was found to have a large adrenal mass, discovered incidentally, during thoracic ultrasound.

Case Presentation

This case report presents the discovery of an adrenal mass in a patient with respiratory distress due to a COPD exacerbation, emphasizing the importance of sonographers’ ability to identify abnormal imaging within their POCUS framework. The clinicians promptly communicated the incidental finding to the patient, leading to further imaging and labs while in the emergency department and subsequent hospital admission. Traumatic arteriovenous fistulas and visceral vascular injuries are rare.

Conclusion

Although adrenal glands are not the primary focus for emergent pathology, the identified mass prompted a comprehensive evaluation, ultimately revealing a nonhormone-secreting adrenal cortical carcinoma. The rarity of this malignancy and the discrepancy between imaging and laboratory results underscore the need for a thorough investigation, with the focus suggesting that POCUS, despite its limitations, can play a crucial role in prompting additional imaging for accurate diagnosis and informed patient management. This case also highlights the significance of transparent communication while empowering patients and guiding further investigations for a comprehensive understanding of the pathology.

Introduction

Over the past several decades, there has been a significant increase in the utilization of point-of-care ultrasound (POCUS) as a vital tool for emergency physicians in patient evaluation. Point-of-care ultrasound also serves as a rapid and noninvasive diagnostic instrument for acute cases with ambiguous symptoms, enabling clinicians to narrow the differential diagnosis, ascertain the etiology of symptoms, and hasten the formulation of a treatment plan.¹ Notably, POCUS has proven an important adjuvant in evaluating intra-abdominal pathology, occasionally detecting incidental findings, such as adrenal masses.² The following case incidentally discovers an adrenocortical carcinoma (ACC) prompting an urgent workup. We then review the workup and diagnosis of ACC, including imaging findings, and discuss the management of “incidentalomas” as it pertains to this case.

Case Presentation

A 59-year-old man was brought to the emergency department (ED) by emergency medical services with worsening shortness of breath for the previous 3 weeks. His medical history included chronic obstructive pulmonary disease (COPD) on 2–4 L of home oxygen and a 60 pack per year tobacco use. Upon arrival, he was hypoxic at 60% SpO₂ and required 10 L of supplemental oxygen to achieve 90% SpO₂. His blood pressure was 100/79 mmHg, and his heart rate was 94 beats per minute. On physical exam, he was tachypneic and spoke in partial sentences with supraclavicular retractions. There was minimal wheezing noted in the expiratory phase on auscultation in all lung fields and 2+ pitting edema in the bilateral lower extremities that were well-perfused, nontender, and nonerythematous. His electrocardiogram demonstrated normal sinus rhythm, right axis deviation (chronic finding), and no signs of acute ischemia.

A cardiac and pulmonary POCUS were performed to evaluate his respiratory distress. Cardiac POCUS with 4 views (subxiphoid, apical, parasternal short and long axis) showed right ventricular dilation with normal left ventricular function consistent with chronic right heart dysfunction. Thoracic POCUS demonstrated small bilateral pleural effusions and B-lines suggestive of pulmonary edema on lower lung fields with normal lung sliding. A large cystic structure below the left diaphragm was incidentally identified and warranted further inspection with renal POCUS. He denied a history of any renal or adrenal medical conditions. A left renal POCUS revealed a large complex suprarenal structure with irregular borders containing an anechoic cystic center, as well as the presence of ascites (Figure 1). The initial laboratory studies and arterial blood gas were within normal limits.

Figure 1.

An ultrasound showed the left inferior lateral thoracic view. Inferior to the left hemidiaphragm (the orange arrow points to the diaphragm), there was a large complex structure without clear borders but with a central, irregularly bordered, anechoic, cystic-like structure (yellow arrow). The spleen and kidney were unidentified in this window. Above the diaphragm, a small anechoic pleural effusion was noted in the costophrenic angle. Color doppler demonstrated vascularity within the structure, consistent with a malignant mass (inset).

The patient was treated with nebulized albuterol/ipratropium, corticosteroids, broad-spectrum antibiotics, and noninvasive ventilation. Once stabilized, a computed tomography (CT) angiogram of the chest was performed to rule out pulmonary embolus, and a CT abdomen/pelvis was done to evaluate the left upper quadrant mass. The patient’s CT scan showed signs of right heart strain, trace right-sided pleural effusion, severe diffuse centrilobular emphysematous changes, and diffuse bilateral axillary, hilar, and mediastinal lymphadenopathy without pulmonary embolus. The dedicated CT of the abdomen/pelvis (Figure 2) confirmed a 12 cm x 11 cm x 11 cm mass with a hemorrhagic and necrotic core concerning for ACC. Moderate ascites were also present. A bilateral lower extremity venous doppler ultrasound demonstrated a nonocclusive right femoral vein thrombosis. Anticoagulation for the deep vein thrombosis was deferred given the suspected hemorrhage in the adrenal mass, and surgical oncology was consulted for inpatient management.

Figure 2.

A computed tomography image showed a large necrotic adrenal mass (yellow arrows) in the transverse (A) and coronal (B) views.

The inpatient workup included labs to further elucidate the adrenal mass activity, as follows (normal values): serum renin 4.415 ng/mL/hr (0.167–5.380 ng/mL/hr), serum aldosterone 11.9 ng/dL (0.0–30.0 ng/dL), 17-hydroxyprogesterone less than 10 ng/dL (27–199 ng/dL), dehydroepiandrosterone less than 20 ng/dL (21–402 ng/dL), testosterone 52.9 ng/dL (241–827 ng/dL), metanephrine 68.6 pg/mL (0.0–88.0 pg/mL), and carcinoembryonic antigen (CEA) 6.2 ng/mL (0.0–5.0 ng/mL). Based on these findings, it was determined that the mass was nonhormone secreting. A pathology report of the ascitic fluid revealed a hypocellular specimen consisting of a few macrophages, histiocytes, and scattered mixed leukocytes.

The surgical oncology team next recommended a biopsy; however, the patient refused the biopsy or additional invasive procedures and was ultimately discharged to hospice. There were multiple unsuccessful attempts over the next 2 months to follow up with the patient via the provided contact information. Eventually, it was confirmed that he passed away.

Discussion

Background

Adrenal tumors typically manifest as small, benign, nonfunctional adrenocortical adenomas, affecting 3% to 10% of the human population.³ In contrast, ACC is a rarer condition, with a prevalence of 1 to 2 cases per million per year.⁴ Approximately 20% to 30% of ACC cases are incidentally diagnosed.^4–6

The existing clinical practice guideline for ACC provided by the European Society of Endocrinology (ESE) advocates for a comprehensive hormone workup to identify potential autonomous excess glucocorticoids, sex hormones, mineralocorticoids, and adrenocortical steroid hormone precursors.⁷

Current data indicate that 85% of adrenal incidentalomas are nonfunctional, while 15% exhibit functional characteristics.⁸ The most frequent presentation involves hypercortisolism, such as plethora, acute-onset diabetes mellitus, muscle weakness/atrophy, and osteoporosis (Cushing syndrome). The second most common presentation is characterized by the secretion of adrenal androgens, leading to rapid-onset male pattern baldness, hirsutism, virilization, and menstrual irregularities.⁹

Adrenocortical carcinomas typically present as large tumors, averaging 10 x 13 cm, characterized by internal hemorrhage, necrosis, and calcifications, resulting in frequent tumor heterogeneity.⁹ Although “cannot miss” diagnoses like pheochromocytomas are rare, their identification is crucial, particularly when presenting with newly decompensated congestive heart failure and persistent hypertension, as these conditions can be fatal.²

The ESE guidelines suggest incorporating a chest CT, in addition to abdominal-pelvic cross-sectional imaging (CT or magnetic resonance image [MRI]), in cases where there is a high suspicion of ACC.⁷ Particularly in a primary tumor exceeding 4 cm, a chest CT or MRI with contrast is important in the evaluation of metastatic disease and local invasions.⁷ On contrast-enhanced CT scans, ACCs typically display irregular peripheral enhancement with a centrally nonenhancing area, indicating hemorrhage or necrosis.¹⁰ Approximately 30% of ACC cases exhibit calcification, manifested as either coarse or microcalcification, usually centrally located and identified by high attenuation foci. Metastases to regional and para-aortic lymph nodes, lungs, livers, and bones are best identified through contrast-enhanced CT scans in ACCs, facilitating accurate disease staging.¹¹ They exhibit an isointense to hypointense appearance distinct from the liver parenchyma on T1-weighted imaging and appear hyperintense on T2-weighted images.¹¹ Lastly, the ESE guidelines discourage adrenal biopsy unless there is evidence of metastatic disease that precludes surgical intervention.⁷

Point-of-Care Testing

While the primary training of traditional POCUS training does not focus on assessing the adrenal glands, there have been reports of incidental findings ranging from benign cysts to pheochromocytomas.² When imaging a mass along the upper pole of the kidneys, it is recommended to use a curvilinear transducer with a frequency of 2–5 MHz in both longitudinal and transverse planes. Preferably, anterior transverse scanning is employed for identifying small adrenal masses, and the use of color flow doppler is considered to assess for vascular involvement, which is significantly more common in malignant lesions.^2,8,12 Normal adrenal gland tissues are expected to appear hypoechoic, but can be difficult to identify since they often exhibit a similar echogenicity to retroperitoneal fat.¹³ They normally measure less than 3 cm in size. In cases where the etiology remains unclear with POCUS, further imaging modalities, such as an abdominal CT or MRI, are warranted. While sonography demonstrates high sensitivity and specificity in detecting the presence of adrenal masses, differentiation between benign and malignant masses cannot be solely based on size. Contrast-enhanced sonography, while comparable in sensitivity to CT/MRI for discerning adrenal masses as benign versus neoplastic, is also not reliable for distinguishing between various histopathologic nonadenomatous lesions.⁸

The ability of an emergency physician to identify pathology early on using POCUS offers a comprehensive approach to patient management. When a mass is detected, emergency physicians should consider pursuing follow-up imaging for further clarification.^2,14 However, reporting of incidental findings varies on experience, documentation, and by institution. The range of these findings were as little as only 1.6% of scans up to 26% of routine POCUS.¹⁵ The extreme end of this range is based on a study of renal and biliary scans by emergency medicine residents.¹⁶ Even in rapid and less thorough exams, providers were able to identify 137 incidental findings over 1452 (9.4%) focused assessment with sonography in trauma (FAST) exams during a 15-month period.^15,17 In another study of 137 patients, 31 (22.6%) of these patients had an incidental finding in the ED. Shockingly, only 6 of these patients were informed of these findings.^15,17

The ability to steer diagnosis, treatment, and future follow-up should allow for transparent communication of incidental findings, granting patients autonomy over their health. The American College of Radiology and Fleischner Society recommend for all incidental findings a standardized protocol that follows evidence-based guidelines to capitalize on cost effectiveness and inter-rater reliability.^15,18–20 Hence, medical providers and their trainees performing POCUS require evidence-based guidelines for when additional imaging is necessary while considering health care costs and patient wellbeing. Each individual institution should be responsible for formulating these protocols, piloting discussions, and conducting training.¹⁵

Conclusion

In an ACC, rigorous workup is essential, involving the measurement of steroid hormones produced by the mass, contrast-enhanced CT/MRI imaging, and biopsy consideration to determine the secretory nature of the mass. In our case, a thoracic POCUS initially detected a suprarenal mass, requiring a clarifying abdominal CT scan, which the intended chest CT scan may have incompletely identified, requiring a potentially unstable patient to return for imaging again and substantially delaying proper identification. The patient was promptly informed about the incidental finding, leading to further imaging and labs during their admission to ascertain an accurate diagnosis. Although the definitive diagnosis was elusive, this information enabled informed decisions, supporting patient autonomy. This case is a reminder of how POCUS has the potential to identify incidental findings unrelated to the initial scan indication, offering significant clinical value in patient care. In cases where emergency physicians come across incidental POCUS findings, there is a need to relay this information and assess whether additional imaging is warranted. Developing a clear follow-up plan becomes essential when necessary. There is room for improvement in EDs, particularly in enhancing the clarity of follow-up recommendations and effectively communicating ultrasound results to patients. Currently there are no guidelines on management of incidental findings on POCUS. The clinician performing the study should follow hospital specific guidelines, document them to avoid malpractice risks, and ensure timely follow-up and workup.