Adrenal incidentaloma (AI) refers to an otherwise unsuspected adrenal mass found in up to 5 % of patients undergoing radiological imaging. As high as one in five incidentalomas are functional; hypersecretion of cortisol causing Cushing’s or Subclinical Cushing’s Syndrome (SCS), catecholamines leading to pheochromocytoma, aldosterone resulting in primary aldosteronism (Conn’s syndrome), androgens leading to virilization of patients, and in very rare cases renin manifesting as secondary aldosteronism.
Renin is a proteolytic enzyme that is synthesized by juxtaglomerular cells. Its release into the bloodstream can be triggered by sympathetic stimulus, decreased arterial blood pressure monitored via baroreceptors or decreased sodium levels in the nephron ultrafiltrates detected by the macula densa of the juxtaglomerular apparatus. Activation of the renin-angiotensin-aldosterone-system (RAAS) helps mediate extracellular volume and arterial vasoconstriction in the body for homeostatic purposes. When the RAAS is over-activated by renin-secreting tumours, the classical symptoms of hypertension, hyperreninism, hyperaldosteronism and hypokalemia results. Primary reninism is usually described in association with renal tumours; with the majority being juxtaglomerular cell tumours. Extra-renal secreting tumours are thus more uncommon and we present two cases in the context of adrenal incidentaloma. Adrenal masses discovered inadvertently on imaging procedures conducted for an initially unforeseen adrenal pathology are known as adrenal incidentalomas (AI). …show more content…
AIs are being picked up with increasing frequency due to the widespread use of radiological imaging tests such as abdominal ultrasonography, CT, and MRI. Autopsy series have quoted the incidence of clinically inapparent adrenal tumours in 1.4-8.7 % of general population. Prevalence is noted to increase with age, from 1 % prior to age of 30 to 7-10 % beyond age of 70. The vast majority of these adrenal masses are in fact non-functional benign cortical adenomas that require no treatment (see Table 1). However, an adrenal incidentaloma still requires investigation and management. There are two important questions to address when evaluating a patient with adrenal incidentaloma ● Is the tumor malignant? If so, is it a primary or metastatic cancer? ● Is the tumor functional? (i.e. is it secreting hormones?) The two major predictors of malignancy on imaging are size and the radiological characteristics of the incidentaloma. The incidence of malignancy for tumors >6 cm, 4-6 cm, and 10, accounting for 30-50 % of adenomas), enhancement washout is valuable in helping further differentiate tumor benignity. Minimum cut off values of 40 % for relative washout and 60 % for absolute washout allows diagnosis of adenoma with a specificity of 100 %. Magnetic resonance imaging offers no additional diagnostic elements in comparison to CT scan except the clinical advantage of pregnant women, children, and patients with allergies to contrast. Positron emission tomography (PET) utilizing 18-fluoro-2-deoxy-glucose (18F-FDG) reflects the metabolic activity of tumours and offers 100 % sensitivity and 94 % specificity to discriminate malignant from benign adrenal lesions. Differentials of a hypermetabolic lesion include pheochromocytoma, adrenocortical carcinoma, metastasis, and lymphoma. Limitations are high cost and the availability of PET scan in institutions. Hence, it is not considered as a routine evaluation of adrenal incidentalomas. Cytologic study with fine-needle aspiration biopsy is often unhelpful except for patients with suspected metastasis in setting of known primary cancer. Pheochromocytoma should always be excluded prior percutaneous biopsy attempt to avoid possible iatrogenic hypertensive crisis. A careful (personal and family) hormonal history and physical examination in conjunction with appropriate laboratory tests should be undertaken for everyone with found AI. AIs are found to be adrenal metastasis in 75 % of cases when patient is known to have a past or current cancer (majority being …show more content…
Certain morphological features such as nuclear grade, venous invasion and sinusoidal invasion were shown to be persistently poor with minimal improvement of intra-observer agreement even post education. (Tissier et al.) Weiss scoring criteria for malignancy was reduced from four (as described in original paper) to three in 1989 when cases with lower Weiss scores were noted to behave in a malignant fashion. Unfortunately, cut-off at three still does not achieve a sensitivity and specificity of 100%. This is reflected in case 2 where despite scoring only two criteria, concerns were raised given that endocrine neoplasms do not always correlate with the histopathological features. Given the large tumour size and weight in conjunction with clinically concerning presentations of hormonal hypersecretion, a benign clinical course was uncertain. This is reflected by the rigorous follow-up and ongoing endocrine and radiological surveillance by the
Renin is a proteolytic enzyme that is synthesized by juxtaglomerular cells. Its release into the bloodstream can be triggered by sympathetic stimulus, decreased arterial blood pressure monitored via baroreceptors or decreased sodium levels in the nephron ultrafiltrates detected by the macula densa of the juxtaglomerular apparatus. Activation of the renin-angiotensin-aldosterone-system (RAAS) helps mediate extracellular volume and arterial vasoconstriction in the body for homeostatic purposes. When the RAAS is over-activated by renin-secreting tumours, the classical symptoms of hypertension, hyperreninism, hyperaldosteronism and hypokalemia results. Primary reninism is usually described in association with renal tumours; with the majority being juxtaglomerular cell tumours. Extra-renal secreting tumours are thus more uncommon and we present two cases in the context of adrenal incidentaloma. Adrenal masses discovered inadvertently on imaging procedures conducted for an initially unforeseen adrenal pathology are known as adrenal incidentalomas (AI). …show more content…
AIs are being picked up with increasing frequency due to the widespread use of radiological imaging tests such as abdominal ultrasonography, CT, and MRI. Autopsy series have quoted the incidence of clinically inapparent adrenal tumours in 1.4-8.7 % of general population. Prevalence is noted to increase with age, from 1 % prior to age of 30 to 7-10 % beyond age of 70. The vast majority of these adrenal masses are in fact non-functional benign cortical adenomas that require no treatment (see Table 1). However, an adrenal incidentaloma still requires investigation and management. There are two important questions to address when evaluating a patient with adrenal incidentaloma ● Is the tumor malignant? If so, is it a primary or metastatic cancer? ● Is the tumor functional? (i.e. is it secreting hormones?) The two major predictors of malignancy on imaging are size and the radiological characteristics of the incidentaloma. The incidence of malignancy for tumors >6 cm, 4-6 cm, and 10, accounting for 30-50 % of adenomas), enhancement washout is valuable in helping further differentiate tumor benignity. Minimum cut off values of 40 % for relative washout and 60 % for absolute washout allows diagnosis of adenoma with a specificity of 100 %. Magnetic resonance imaging offers no additional diagnostic elements in comparison to CT scan except the clinical advantage of pregnant women, children, and patients with allergies to contrast. Positron emission tomography (PET) utilizing 18-fluoro-2-deoxy-glucose (18F-FDG) reflects the metabolic activity of tumours and offers 100 % sensitivity and 94 % specificity to discriminate malignant from benign adrenal lesions. Differentials of a hypermetabolic lesion include pheochromocytoma, adrenocortical carcinoma, metastasis, and lymphoma. Limitations are high cost and the availability of PET scan in institutions. Hence, it is not considered as a routine evaluation of adrenal incidentalomas. Cytologic study with fine-needle aspiration biopsy is often unhelpful except for patients with suspected metastasis in setting of known primary cancer. Pheochromocytoma should always be excluded prior percutaneous biopsy attempt to avoid possible iatrogenic hypertensive crisis. A careful (personal and family) hormonal history and physical examination in conjunction with appropriate laboratory tests should be undertaken for everyone with found AI. AIs are found to be adrenal metastasis in 75 % of cases when patient is known to have a past or current cancer (majority being …show more content…
Certain morphological features such as nuclear grade, venous invasion and sinusoidal invasion were shown to be persistently poor with minimal improvement of intra-observer agreement even post education. (Tissier et al.) Weiss scoring criteria for malignancy was reduced from four (as described in original paper) to three in 1989 when cases with lower Weiss scores were noted to behave in a malignant fashion. Unfortunately, cut-off at three still does not achieve a sensitivity and specificity of 100%. This is reflected in case 2 where despite scoring only two criteria, concerns were raised given that endocrine neoplasms do not always correlate with the histopathological features. Given the large tumour size and weight in conjunction with clinically concerning presentations of hormonal hypersecretion, a benign clinical course was uncertain. This is reflected by the rigorous follow-up and ongoing endocrine and radiological surveillance by the