Adrenocortical carcinoma masquerading as Cushing’s disease

BMJ Case Reports 2017; doi:10.1136/bcr-2016-217519

Summary

Cushing’s syndrome (CS) can be classified as adrenocorticotropic hormone (ACTH)-dependent or ACTH-independent depending on the ACTH levels.

However, 30% of the patients with CS have ACTH levels in the ‘grey zone’ (5–20 pg/mL), thereby posing a challenge in establishing the aetiological diagnosis. In a patient with full-blown features of Cushing’s syndrome with equivocal ACTH levels, and a pituitary microadenoma on contrast-enhanced MRI sella, can falsely lead to a diagnosis of Cushing’s disease. Pituitary microadenoma, if <6 mm in size, may be an incidental finding (incidentaloma) in this scenario and can be present in ∼3–27% of the healthy population. Therefore, in a patient with CS with equivocal ACTH levels and a pituitary microadenoma, multiple samplings for ACTH and adrenal imaging should be performed to exclude ACTH-independent CS and if required, bilateral inferior petrosal sinus sampling to determine the source of ACTH excess.

Find the entire article here: http://casereports.bmj.com/content/2017/bcr-2016-217519.full

A Faster Way to Diagnose Cushing’s Syndrome

Diagnosing Cushing’s syndrome can take 24 hours of complicated and repeated analysis of blood and urine, brain imaging, and tissue samples from sinuses. But that may soon be in the past: National Institutes of Health (NIH) researchers have found that measuring cortisol levels in hair samples can do the same job faster.

Patients with Cushing’s syndrome have a high level of cortisol, perhaps from a tumor of the pituitary or adrenal glands, or as a side effect from medications. In the study, 36 participants—30 with Cushing’s syndrome, six without—provided hair samples divided into three equal segments. The researchers found that the segments closest to the scalp had the most cortisol (96.6 ± 267.7 pg/mg for Cushing’s syndrome patients versus 14.1 ± 9.2 pg/mg in control patients). Those segments’ cortisol content correlated most closely with the majority of the initial biochemical tests, including in blood taken at night (when cortisol levels normally drop).

The study was small; Cushing’s syndrome is rare, and it’s hard to recruit large numbers of patients. Still, the researchers believe it is the largest of its kind to compare hair cortisol levels to diagnostic tests in Cushing’s patients. “Our results are encouraging,” said Mihail Zilbermint, MD, the study’s senior author and an endocrinologist at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development. “We are hopeful that hair analysis may ultimately prove useful as a less-invasive screening test for Cushing’s syndrome or in helping to confirm the diagnosis.” The authors suggest the test is also a convenient alternative with the “unique ability” for retrospective evaluation of hypercortisolemia over months.

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From https://www.ptcommunity.com/journal/article/full/2017/4/271/research-briefs-april-2017

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