Imaging in Cushing's syndrome

Once the diagnosis of Cushing's syndrome (CS) has been established, the main step is to differentiate between ACTH dependent and independent disease. In adults, 80% of CS is due to ACTH-dependent causes and 20% due to adrenal causes. ACTH-secreting neoplasms cause ACTH-dependent CS. These are usually anterior pituitary microadenomas, which result in the classic Cushing's disease. Non-pituitary ectopic sources of ACTH, such as a small-cell lung carcinoma or carcinoid tumours, are the source of the remainder of ACTH-dependent disease. In the majority of patients presenting with clinical and biochemical evidence of CS, modern non-invasive imaging can accurately and efficiently provide the cause and the nature of the underlying pathology. Imaging is essential for determining the source of ACTH in ectopic ACTH production, locating the pituitary tumours and distinguishing adrenal adenomas, carcinomas and hyperplasias. In our chapter we review the adrenal appearances in ACTH-dependent and ACTH-independent CS. We also include a discussion on the use of MRI and CT for the detection and management of pituitary ACTH secreting adenomas. CT of the chest, abdomen and pelvis with intravenous injection of contrast medium is the most sensitive imaging modality for the identification of the ectopic ACTH source and detecting adrenal pathology. MRI is used for characterising adrenal adenomas, problem solving in difficult cases and for detecting ACTH-secreting pituitary adenomas.

The indeterminate adrenal mass in patients with cancer

With the increasing use of abdominal cross-sectional imaging, incidental adrenal masses are frequently detected. The commonest clinical question is whether these are benign adenomas or malignant primary or secondary masses. The nature of incidentally detected adrenal masses can be determined with a high degree of accuracy using computed tomography (CT) and magnetic resonance imaging (MRI) as benign adrenal masses such as myelolipomas, lipid-rich adenomas, adrenal cysts and adrenal haemorrhage which have pathognomonic imaging findings. However, there remains a significant overlap between the imaging features of some lipid-poor adenomas and malignant lesions. We review the recent advances in CT, MRI and positron emission tomography (PET) which can be used to distinguish between benign adenomas and malignant lesions of the adrenal gland.

MR imaging in ovarian cancer

Magnetic resonance (MR) imaging is increasingly being used in patients with gynaecological disorders due to its high contrast resolution compared to computed tomography (CT) and ultrasound. In women presenting with an adnexal mass, ultrasound remains the primary imaging modality in the detection and characterisation of such lesions. However, in recent years overwhelming evidence has accumulated for the use of MR imaging in patients with indeterminate adnexal masses particularly in younger women and where disease markers are unhelpful. In staging ovarian cancer and for evaluating therapeutic response MR imaging is as accurate as CT but CT remains the imaging modality of choice because it is more widely available and quicker. This article reviews that evidence and outlines a place for the use of MR imaging in ovarian cancer.

The optimal imaging of adrenal tumours: a comparison of different methods

Computed tomography (CT; unenhanced, followed by contrast-enhanced examinations) is the cornerstone of imaging of adrenal tumours. Attenuation values of <10 Hounsfield units on an unenhanced CT are practically diagnostic for adenomas. When lesions cannot be characterised adequately with CT, magnetic resonance imaging (MRI) evaluation (with T1- and T2-weighted sequences and chemical shift and fat-suppression refinements) is sought. Functional nuclear medicine imaging is useful for adrenal lesions that are not adequately characterised with CT and MRI. Scintigraphy with [(131)I]-6-iodomethyl norcholesterol (a labelled cholesterol analogue) can differentiate adrenal cortical adenomas from carcinomas. Phaeochromocytomas appear as areas of abnormal and/or increased uptake of [(123)I]- and [(131)I]-meta-iodobenzylguanidine (a labelled noradrenaline analogue). The specific and useful roles of adrenal imaging include the characterisation of tumours, assessment of true tumour size, differentiation of adenomas from carcinomas and metastases, and differentiation of hyperfunctioning from non-functioning lesions. Adrenal imaging complements and assists the clinical and hormonal evaluation of adrenal tumours.

Differential diagnosis of adnexal masses: risk of malignancy index, ultrasonography, magnetic resonance imaging, and radioimmunoscintigraphy

A risk of malignancy index (RMI), based on menopausal status, ultrasound (US) findings, and serum CA125, has previously been described and validated in the primary evaluation of women with adnexal masses and is widely used in selective referral of women from local cancer units to specialized cancer centers. Additional imaging modalities could be useful for further characterization of adnexal masses in this group of women. A prospective cohort study was conducted of 196 women with an adnexal mass referred to a teaching hospital for diagnosis and management. Follow-up data was obtained for 180 women; 119 women had benign and 61 women malignant adnexal masses. The sensitivity and specificity of specialist US, magnetic resonance imaging (MRI), radioimmunoscintigraphy (RS), and the RMI were determined. We identified a subgroup of women with RMI values of 25-1000 where the value of further specialist imaging was evaluated. Sensitivity and specificity for specialist US were 100% and 57%, for MRI 92% and 86%, and for RS 76% and 87%, respectively. Analysis of 123 patients managed sequentially, using RMI cutoff values of > or =25 and <1000 and then US and MRI provided a sensitivity of 94% and a specificity of 90%. Using this RMI cutoff followed by specialist US and MRI, as opposed to the traditional RMI cutoff value of 250, can increase the proportion of patients with cancer appropriately referred in to a cancer center, with no change in the proportion of patients with benign disease being managed in a local unit.

Imaging of neuroendocrine tumours (CT/MR/US)

Neuroendocrine tumours may be broadly divided into pancreatic endocrine tumours (PETs) and carcinoid neuroendocrine tumours (NETs). In both cases, patients may present with a clinical syndrome related to hormone secretion by the tumour. In these cases, cross-sectional imaging plays an important role in the localization of the primary tumour, the detection of metastases, and the assessment of response to treatment. Computed tomography (CT) is established as the primary modality, although following technological advances detection rates on magnetic resonance imaging (MRI) are now challenging those of CT. Endoscopic ultrasound has an important role in the preoperative assessment of the pancreas where a small functioning tumour or the possibility of multiple tumours is suspected. The sensitivity for the detection of small functioning tumours depends upon optimal technique, whichever modality is used. Non-functioning tumours frequently present late with mass effect, as there is no accompanying clinical syndrome. Carcinoid neuroendocrine tumours are most frequently localized on CT. MRI is usually used as a problem-solving tool. As technology evolves, detection rates may continue to improve, and the highest sensitivities may be achieved by a combination of different modalities.

The performance of magnetic resonance imaging in early cervical carcinoma: a long-term experience

We report our long-term experience of performance of magnetic resonance imaging (MRI) in localizing cervical tumor, assessing tumor size, staging, and lymph node infiltration in patients with early cervical cancer. MRI of 150 patients with early carcinoma between 1995-2005 was retrospectively reviewed. Tumor location, size, tumor distance from internal os, parametrial invasion, myometrial invasion, lymph node size, and location were documented. All patients underwent surgery, pelvic lymphadenectomy, and histological correlation of MRI findings. For staging, MRI and histopathology had kappa value of 0.89. For parametrial invasion, MRI had specificity, negative predictive value (NPV) of 97% and 100%, respectively. For tumor size, MRI and histology had mean difference of -0.9 mm with 95% limits of agreement between -12.6 to +13 mm. In tumors greater than 10 mm, mean difference was 0.3 mm and limits of agreement were -7.5 to +7.9 mm. For internal os involvement sensitivity, specificity, positive predictive value (PPV) and NPV were 90%, 98%, 86%, 98%. respectively. For myometrial invasion sensitivity, specificity, NPV, and PPV were 100%, 99%, 88%, 100%, respectively. Incidence of nodal metastases was 2.9%. On a per-patient basis, sensitivity, specificity for nodal involvement was 37% and 92% and on node-by-node basis, sensitivity and specificity of MRI was 27% and 99%, respectively. Our study confirms MRI is highly accurate in localizing cervical tumor, excluding parametrial invasion, confirming myometrial and internal os invasion. MRI is therefore useful in selecting patients for surgery and mandatory in patients for fertility-preserving surgery. Using accepted size criteria for nodal involvement, MRI is insensitive and currently will not avoid need for pelvic lymphadenectomy.

Evaluation of endometrial carcinoma on magnetic resonance imaging

Our aims were to assess diagnostic performance of T2-weighted (T2W) and dynamic gadolinium-enhanced T1-weighted (T1W) magnetic resonance imaging (MRI) in the preoperative assessment of myometrial and cervical invasion by endometrial carcinoma and to identify imaging features that predict nodal metastases. Two radiologists retrospectively reviewed MR images of 96 patients with endometrial carcinoma. Tumor size, depth of myometrial and cervical invasion, and nodal enlargement were recorded and then correlated with histology. The sensitivity, specificity, positive and negative predictive values (PPV and NPV) for the identification of any myometrial invasion (superficial or deep) were 0.94, 0.50, 0.93, 0.55 on T2W and 0.92, 0.50, 0.92, 0.50 on dynamic T1W, and for deep myometrial invasion were 0.84, 0.78, 0.65, 0.91 on T2W and 0.72, 0.88, 0.72, 0.88 on dynamic T1W. The sensitivity, specificity, PPV and NPV for any cervical invasion (endocervical or stromal) were 0.65, 0.87, 0.57, 0.90 on T2W and 0.50, 0.90, 0.46, 0.92 on dynamic T1W, and for cervical stromal involvement were 0.69, 0.95, 0.69, 0.95 on T2W and 0.50, 0.96, 0.57, 0.95 on dynamic T1W. Leiomyoma or adenomyosis were seen in 73% of misdiagnosed cases. Sensitivity and specificity for the detection of nodal metastases was 66% and 73%, respectively. Fifty percent of patients with cervical invasion on MRI had nodal metastases. In conclusion, MRI has a high sensitivity for detecting myometrial invasion and a high NPV for deep invasion. MRI has a high specificity and NPV for detecting cervical invasion. Dynamic enhancement did not improve diagnostic performance. MRI may allow accurate categorization of cases into low- or high-risk groups ensuring suitable extent of surgery and adjuvant therapy

Recurrent endometrial cancer: patterns of recurrent disease and assessment of prognosis

AIM

To evaluate patterns of disease and identify factors predicting outcome in patients presenting with recurrent endometrial adenocarcinoma following primary surgery.

MATERIALS AND METHODS

A retrospective review was performed of the imaging and clinical data in 86 patients (median age 66 years, range 42-88 years) presenting with recurrent endometrial adenocarcinoma following primary surgery.

RESULTS

Following primary surgery recurrent disease occurred within 2 years in 64% and within 3 years in 87%. Relapse was seen within lymph nodes in 41 (46%), the vagina in 36 (42%) the peritoneum in 24 (28%) and the lung in 21 (24%). Unusual sites of disease included spleen, pancreas, rectum, muscle and brain. Univariate survival analysis showed the factors significant for poor outcome were: multiple sites of disease, liver and splenic disease, haematogenous, peritoneal and nodal spread, poorly differentiated tumour, and early relapse. The presence of disease within the vagina, bladder or lung was not associated with poor prognosis. Multivariate analysis identified multiple sites of disease, liver and splenic metastases to be independent predictors of poor outcome.

CONCLUSION

The most frequently observed sites of relapse are: lymph nodes, vagina, peritoneum and lung. Significant predictors of poor outcome in recurrent disease are multiple sites of disease and liver and splenic metastases.

Insulinomas may present with normoglycemia after prolonged fasting but glucose-stimulated hypoglycemia

BACKGROUND

Insulinomas are rare but are the most common cause of hyperinsulinemic hypoglycemia in the adult population. Diagnosis of this pathology relies on clinical features along with laboratory tests and imaging investigations to aid in localization. One of the most robust standard tests used for establishing a biochemical diagnosis is the prolonged (72 h) fast. Currently, it is recommended that a prolonged supervised fast be performed, at least for 48 h if not for 72 h, and many would take the absence of hypoglycemia after a 72-h fast as evidence excluding the diagnosis.

METHODS

We employed prolonged fasts and standard glucose tolerance tests, plus imaging studies and surgical pathology, in two patients with suspected insulinomas.

RESULTS

The prolonged 72-h fast was normal in both the patients, whereas in both cases a prolonged oral glucose tolerance test clearly demonstrated the induction of severe hyperinsulinemia followed by significant hypoglycemia. Surgical removal confirmed the presence of insulinomas in each case.

CONCLUSIONS

Although the sensitivity of the 72-h fast is high and still plays an important role in the diagnosis of an insulinoma, we suggest that a "normal" test result should be interpreted in the light of clinical symptoms.

Selective parathyroid venous sampling in patients with complicated hyperparathyroidism

OBJECTIVE

The role of preoperative localisation of abnormal parathyroid glands remains controversial but is particularly relevant to the management of patients with recurrent or persistent hyperparathyroidism and familial syndromes. We report our experience of the use of selective parathyroid venous sampling (PVS) in the localisation of parathyroid disease in such patients.

DESIGN

We report a retrospective 10-year experience (n = 27) of the use of PVS in complicated primary hyperparathyroidism and contrast the use of PVS with neck ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) and sestamibi imaging modalities.

RESULTS

In 14 out of 25 patients who underwent surgery PVS results were completely concordant with surgical and histological findings and 88% of patients achieved post-operative cure. Out of 13 patients referred after previous failed surgery, 12 underwent further surgery which was curative in 9. In total PVS yielded useful positive (n = 13) and/or negative information (n = 6) in 19 out of 25 patients undergoing surgery. Using histology as the gold standard, 59% of PVS studies were entirely consistent with histology, as compared with 39% of ultrasound scans, 36% of sestamibi scans and 17% of MRI/CT scans.

CONCLUSIONS

PVS is a valuable adjunct to MRI/CT and sestamibi scanning in selected patients with complicated hyperparathyroidism when performed in an experienced unit.

CT/MRI of neuroendocrine tumours

Neuroendocrine tumours (NETs) are often thought to be rare and rather recherché cancers which are of little concern to the general physician, surgeon or radiologist because of their rarity and esoteric nature. In fact, while relatively uncommon, the total group of gastro-entero-pancreatic (GEP) tumours incorporates the spectrum of all types of carcinoids, including bronchial carcinoids, and the whole gamut of islet-cell tumours. Some of these may present as functioning tumours, with a plethora of hormonal secretions and concomitant clinical syndromes, and GEPs in general have an incidence around 30 per million population per year. This means that in the whole European Union, for example, there will be in the region of 12,000 new patients every year presenting with one or another manifestation of these tumours. Furthermore, the comparatively long survival of many of these patients, compared to more common adenocarcinomas or epithelial tumours, implies that the point prevalence is also not inconsiderable. However, it is undoubtedly true that these tumours can be difficult to identify, especially in their early stages, and it is then that radiological investigation becomes of paramount importance. Having taken into account all these considerations, most investigators would initiate investigation of a suspected or biochemically proven islet-cell tumour with cross-sectional imaging-either CT or MRI. This will clearly identify the larger lesions, allow assessment of the entire abdomen, and provide valuable information on the presence of hepatic metastates.

Can MRI rule out bladder and rectal invasion in cervical cancer to help select patients for limited EUA?

OBJECTIVES

Although invasion of the bladder or rectum is rare in cervical carcinoma, endoscopic assessment of both organs is part of the standard FIGO clinical staging system, with associated increase in cost and risk of complications. Our objective was to evaluate whether MRI could be used to select patients who did not require invasive staging of the bladder or rectum.

METHODS

Two observers, blinded to the results of cystoscopy and endoscopic examination of the rectum, retrospectively reviewed the MR images of 112 patients with cervical carcinoma. A 5-point invasion score was used to determine bladder and rectal invasion (1 = no invasion, 5 = definite invasion). A confidence score of 3 or above was used to identify patients with possible bladder or rectal involvement. The results of cystoscopy and endoscopic examination of the rectum were recorded and correlated with the MR findings.

RESULTS

MRI was negative for both bladder and rectal invasion in 94/112 patients. Cystoscopy and endoscopic examination of the rectum were confirmed to be normal in all 94 cases. MRI identified 12 patients with possible rectal invasion, 2 confirmed at endoscopy. MRI identified 14 patients with possible bladder invasion, one confirmed at cystoscopy. Using a low threshold cut-off score of >3 to predict invasion resulted in a 100% negative predictive value (NPV) in detection of bladder and rectal invasion.

CONCLUSION

The absence of bladder or rectal invasion can be diagnosed with sufficient confidence using an MRI scoring system to safely obviate the need for invasive cystoscopic or endoscopic staging in the majority of patients with cervical cancer. This could potentially lead to a reduction in staging costs and morbidity.

MR imaging appearances of the female pelvis after trachelectomy

Carcinoma of the cervix has a predilection for affecting young women. In recent years, surgical procedures that combine local radical surgery with maintenance of fertility potential in young women have been investigated. One such procedure is radical trachelectomy with pelvic lymphadenectomy, in which the corpus uteri is preserved, thus maintaining fertility potential. Magnetic resonance (MR) imaging is useful in the selection of suitable patients for trachelectomy and in postsurgical follow-up. The MR imaging findings in 45 patients who underwent trachelectomy at one institution between 1996 and 2004 were retrospectively reviewed. The uterovaginal anastomosis has variable appearances, with an end-to-end anastomotic appearance or a vaginal neofornix seen after surgery; suture artifacts can also occur. Possible changes affecting the vagina include diffuse wall thickening and hematomas, whereas lymphoceles and exaggeration of the pelvic venous plexuses can occur in the pelvis. Adenomyosis and endometriosis may be found incidentally in this patient group. Successful pregnancies after trachelectomy have been reported and should be treated as high-risk pregnancies. Knowledge of these MR imaging appearances will help radiologists distinguish between normal postsurgical variations, benign postsurgical changes, and recurrent disease in patients who have undergone trachelectomy.

The ectopic adrenocorticotropin syndrome: clinical features, diagnosis, management, and long-term follow-up

CONTEXT

There are few large series of patients with ectopic, nonpituitary, corticotropin (ACTH) secretion (EAS).

OBJECTIVE

The objective of this study was to analyze the clinical, biochemical, and radiological features, management, and treatment outcome of patients with EAS.

DESIGN

This was a retrospective case-record study.

SETTING

The setting for this study was a tertiary referral hospital center.

PATIENTS

Forty patients with EAS were studied.

MAIN OUTCOME MEASURES

Clinical, biochemical, and radiological features and response to therapy and survival were measured.

RESULTS

The median follow-up was 5 yr (range, 2-30 yr). None of the dynamic tests achieved 100% accuracy, but bilateral inferior petrosal sinus sampling showed an absent central gradient in all but one case (one of 12). Imaging correctly identified the lesion at first investigation in 65% of cases. Bronchial carcinoid tumors were the most common cause of EAS (n = 12; 30%), followed by other neuroendocrine tumors (n = 13, 32.5%). In 12.5% of patients, the source of EAS was never found. Octreotide scintigraphy and whole-body venous sampling were of limited value. Surgical attempt at curative resection was successful in 83% (10 of 12) of patients with bronchial carcinoid tumors; others responded generally well to adrenolytic therapy or bilateral adrenalectomy. Tumor histology and the presence of distant metastases were the main predictors of overall survival (P < 0.05).

CONCLUSIONS

A variety of tests and imaging studies are necessary for the correct diagnosis of the EAS, but even then, up to 20% of cases present a covert or occult EAS syndrome. These cases require a prolonged follow-up, review, and repetition of diagnostic tests and scans.

Mapping pelvic lymph nodes: Guidelines for delineation in intensity-modulated radiotherapy

PURPOSE

To establish guidelines for delineating the clinical target volume for pelvic nodal irradiation by mapping the location of lymph nodes in relation to the pelvic anatomy.

METHODS AND MATERIALS

Twenty patients with gynecologic malignancies underwent magnetic resonance imaging with administration of iron oxide particles. All visible lymph nodes were outlined. Five clinical target volumes were generated for each patient using modified margins of 3, 5, 7, 10, and 15 mm around the iliac vessels. The nodal contours were then overlaid and individual nodes analyzed for coverage. The volume of normal tissue within each clinical target volume and planning target volume was also measured to aid selection of the margin that could provide maximal nodal, but minimal normal tissue, coverage.

RESULTS

In total, 1216 nodal contours were evaluated. The nodal coverage was 56%, 76%, 88%, 94%, and 99% using vessel margins of 3, 5, 7, 10, and 15 mm, respectively. The mean volume of bowel within the planning target volume was 146.9 cm3 with a 7-mm margin, 190 cm3 with a 10-mm margin, and 266 cm3 with a 15-mm margin. Minor modification to the 7-mm margin ensured 99% coverage of the pelvic nodes.

CONCLUSION

Blood vessels with a modified 7-mm margin offer a good surrogate target for pelvic lymph nodes. By making appropriate adjustments, coverage of specific nodal groups may be increased and the volume of normal tissue irradiated decreased. On the basis of these findings, recommended guidelines for outlining pelvic nodes have been produced.

Embryology of the adrenal glands and its relevance to diagnostic imaging

An understanding of the embryology of the adrenal glands is necessary to appreciate the location of adrenal ectopic, or rest, tissue which can occur anywhere along the course of gonadal descent. This tissue usually has no clinical significance, but may become hyperplastic in patients with primary or secondary adrenal pathology. In congenital adrenal hyperplasia, hyperplastic rest tissue may present as a soft-tissue mass, particularly in the gonads and retroperitoneum, and may be mistaken for tumour. The adrenal in the neonate is proportionately much larger than in the adult; in renal ectopy or agenesis the ipsilateral adrenal is normally sited and may be mistaken for a kidney because of its size. This review article illustrates the embryology of the adrenal with particular emphasis on the relevance of embryology to pathology.

Imaging functional adrenal disorders

Technological developments in cross-sectional imaging have revolutionized the localization and characterization of functioning adrenal pathology. With effective use of modern imaging, the diagnosis of the cause and nature of functioning adrenal pathology can be reached speedily, accurately and efficiently in the majority of patients. We review the appearance of primary and secondary adrenal pathology, evaluate the diagnostic performance of imaging modalities, highlight newer technical developments, and propose a rational use of these tests in identifying functioning adrenal disease.

Diagnostic performance of nanoparticle-enhanced magnetic resonance imaging in the diagnosis of lymph node metastases in patients with endometrial and cervical cancer

PURPOSE

Lymph node metastases affect management and prognosis of patients with gynecologic malignancies. Preoperative nodal assessment with computed tomography or magnetic resonance imaging (MRI) is inaccurate. A new lymph node-specific contrast agent, ferumoxtran-10, composed of ultrasmall particles of iron oxide (USPIO), may enhance the detection of lymph node metastases independent of node size. Our aim was to compare the diagnostic performance of MRI with USPIO against standard size criteria.

METHODS

Forty-four patients with endometrial (n = 15) or cervical (n = 29) cancer were included. MRI was performed before and after administration of USPIO. Two independent observers viewed the MR images before lymph node sampling. Lymph node metastases were predicted using size criteria and USPIO criteria. Lymph node sampling was performed in all patients.

RESULTS

Lymph node sampling provided 768 pelvic or para-aortic nodes for pathology, of which 335 were correlated on MRI; 17 malignant nodes were found in 11 of 44 patients (25%). On a node-by-node basis, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) by size criteria were 29%*, 99%, 56%, and 96%, and by USPIO criteria (reader 1/reader 2) were 93%/82%* (*P = .008/.004), 97%/97%, 61%/59%, and 100%/99%, respectively (where [*] indicates the statistical difference of P = x/x between the two results marked by the asterisk). On a patient-by-patient basis, sensitivity, specificity, PPV, and NPV by size criteria were 27%*, 94%, 60%, and 79%, and by USPIO criteria (reader 1/reader 2) were 100%/91%* (*P = .031/.06), 94%/87%, 82%/71%, and 100%/96%, respectively. The kappa statistic was 0.93.

CONCLUSION

Lymph node characterization with USPIO increases the sensitivity of MRI in the prediction of lymph node metastases, with no loss of specificity. This may greatly improve preoperative treatment planning.

The role of magnetic resonance imaging and ultrasound in patients with adnexal masses

AIMS

To evaluate the accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) in characterizing adnexal masses, and to determine which patients may benefit from MRI.

METHODS

We prospectively studied 72 women (mean age 53 years, range 19 to 86 years) with clinically suspected adnexal masses. A single experienced sonographer performed transabdominal and transvaginal greyscale spectral and colour Doppler examinations. MRI was carried out on a 1.5T system using T1, T2 and fat-suppressed T1-weighted sequences before and after intravenous injection of gadolinium. The adnexal masses were categorized as benign or malignant without knowledge of clinical details, according to the imaging features which were compared with the surgical and pathological findings.

RESULTS

For characterizing lesions as malignant, the sensitivity, specificity and accuracy of MRI were 96.6%, 83.7% and 88.9%, respectively, and of US were 100%, 39.5% and 63.9%, respectively. MRI was more specific (p<0.05) than US. Both MRI and US correctly diagnosed 17 (24%) cases with benign and 28 (39%) cases with malignant masses. MRI correctly diagnosed 19 (26%) cases with benign lesion(s), which on US were thought to be malignant. The age, menopausal status and CA-125 levels in these women made benign disease likely, but US features were suggestive of malignancy (large masses and solid-cystic lesions with nodules).

CONCLUSION

MRI is more specific and accurate than US and Doppler assessment for characterizing adnexal masses. Women who clinically have a relatively low risk of malignancy but who have complex sonographic features may benefit from MRI.

Clinical features, diagnosis, treatment and molecular studies in paediatric Cushing's syndrome due to primary nodular adrenocortical hyperplasia

BACKGROUND

Primary nodular adrenocortical hyperplasia (PNAH) is a well recognized, but infrequently studied cause of paediatric Cushing's syndrome (CS).

OBJECTIVE

To assess presentation, diagnosis, radiological imaging, treatment and molecular analysis of patients with childhood-onset CS due to PNAH.

PATIENTS

Four males and two females (median age 12.9 years, range 10.9-16.9 years) were studied.

RESULTS

All had growth failure (mean height SDS -1.2; range -2.5-0.0), weight gain [mean body mass index (BMI) SDS 3.5; range 2.5-4.6] and clinical virilization, while five had hypertension [mean systolic blood pressure (SBP) 130 mmHg, diastolic blood pressure (DBP) 83 mmHg]. One patient had generalized lentigines, one had a tibial chondromyxomatous cyst and two had facial freckling. One patient had a family history of primary nodular adrenocortical disease. The diagnosis of CS was based on elevation of sleeping midnight serum cortisol and urinary free cortisol excretion, and impaired suppression of cortisol on both low- and high-dose dexamethasone suppression tests (DST). All patients had undetectable plasma ACTH with absent responses of both plasma ACTH and serum cortisol to an intravenous (i.v.) corticotrophin-releasing hormone (CRH) test. Computed tomography or magnetic resonance imaging showed normal or small adrenals, with nodules in two patients. All patients underwent bilateral adrenalectomy, performed by open (n = 2) or laparoscopic surgery (n = 4) at a mean of 0.4 years (range 0.2-0.8 years) from diagnosis. Hypercortisolaemia was treated preoperatively by metyrapone alone 0.50-0.75 g/day (n = 4), metyrapone 0.75-1.50 g/day + o'p'DDD/mitotane 1-2 g/day (n = 1), or ketoconazole (n = 1). Adrenal histology showed nodular cortical hyperplasia with shrinkage of intervening cortical tissue and pigmentation, present in four patients. Molecular analysis of the type 1-alpha regulatory subunit of protein kinase A (PRKAR1A) gene revealed a novel germline mutation in one patient. Postadrenalectomy, three patients, had catch-up growth with height velocities increasing from 3.0, 3.9 and 2.5-8.9, 8.3 and 9.0 cm/years, respectively. All six are well at a follow-up (mean 4.0 years; range 0.5-10.8 years).

CONCLUSIONS

PNAH was associated with cushingoid features, virilization and hypertension with a lack of cortisol suppression on high DST, undetectable plasma ACTH and absent cortisol and ACTH responses to CRH. Adrenals were normal or small on imaging. PRKAR1A gene analysis may be helpful in the assessment of these patients.

Bronchiectasis, Exacerbation Indices, and Inflammation in Chronic Obstructive Pulmonary Disease

Relationships between high-resolution computed tomography (HRCT) findings in chronic obstructive pulmonary disease (COPD) and bacterial colonization, airway inflammation, or exacerbation indices are unknown. Fifty-four patients with COPD (mean [SD]: age, 69 [7] years; FEV(1), 0.96 [0.33] L; FEV(1) [percent predicted], 38.1 [13.9]%; FEV(1)/forced vital capacity [percent predicted], 40.9 [11.8]%; arterial partial pressure of oxygen, 8.77 [1.11] kPa; history of smoking, 50.5 [33.5] smoking pack-years) underwent HRCT scans of the chest to quantify the presence and extent of bronchiectasis or emphysema. Exacerbation indices were determined from diary cards over 2 years. Quantitative sputum bacteriology and cytokine measurements were performed. Twenty-seven of 54 patients (50%) had bronchiectasis on HRCT, most frequently in the lower lobes (18 of 54, 33.3%). Patients with bronchiectasis had higher levels of airway inflammatory cytokines (p = 0.001). Lower lobe bronchiectasis was associated with lower airway bacterial colonization (p = 0.004), higher sputum interleukin-8 levels (p = 0.001), and longer symptom recovery time at exacerbation (p = 0.001). No relationship was seen between exacerbation frequency and HRCT changes. Evidence of moderate lower lobe bronchiectasis on HRCT is common in COPD and is associated with more severe COPD exacerbations, lower airway bacterial colonization, and increased sputum inflammatory markers.

Imaging evaluation of the non-functioning indeterminate adrenal mass

With the increasing use of abdominal cross-sectional imaging in the investigation of patient symptoms and in cancer staging, incidental adrenal masses are frequently detected. The most common clinical question is whether these masses are benign or malignant. Benign adrenal masses such as myelolipomas, lipid-rich adenomas, adrenal cysts and adrenal haemorrhage have pathognomonic imaging findings. However, there remains a significant overlap between the imaging appearances of some lipid-poor adenomas and malignant lesions, particularly metastases and small adrenal carcinomas. Our review looks at the recent advances in computed tomography, magnetic resonance imaging and positron emission tomography, which can be used to assist in the distinction between benign adenomas and malignant lesions of the adrenal gland.