“My feet are killing me!” An unusual presentation of Cushing’s syndrome

Adverse effects of steroid excess on bone metabolism are well established but presentation of Cushing’s syndrome with metabolic bone disease is reported to be uncommon. We describe a case of Cushing’s syndrome presenting with pathological fractures probably present for 8 years before diagnosis.

A 33 year old nurse first sustained spontaneous stress fractures of her metatarsals in 1994, with repeated fractures occurring up to 2002. In 2001 she developed hypertension, acute lumbar back pain and gained weight.

In 2002 she was admitted to hospital with chest/back pain. Lumbar spine X-ray showed new fracture of L3,old fractures of L4/5,with fractured ribs on CXR. Isotope bone scan revealed multiple hot spots. MRI showed collapse of T8 with features consistent with malignant disease. The primary malignancy was sought and a left-sided 1.5 centimetre thyroid nodule detected.

Suspicious cytology prompted thyroid lobectomy revealing follicular variant of papillary carcinoma. T8 biopsy revealed chronic infection with Propionobacteria rather than metastatic carcinoma. Despite antibiotic therapy further spontaneous vertebral fractures developed. Bone densitometry revealed Z scores of minus 2.4 at L2-4, minus 2.5 and 2.9 at the hips.

Referral to our centre prompted investigations for Cushing’s syndrome. Serum potassium was 4.1 millimols per litre, androgens, calcitonin and urinary catecholamines all normal. TSH was suppressed by T4 therapy. Urinary free cortisol values were raised,(563-959 nanomols per 24hours) with loss of diurnal rhythm in cortisol secretion (9am 429-586,midnight 397-431 nanomols per litre)and no suppression on low or high dose dexamethasone. Abdominal CT showed a 3.5 centimetre adrenal mass. These findings were consistent with adrenal dependent Cushing’s syndrome. Risedronate and metyrapone were commenced before adrenalectomy, completion thyroidectomy and ablative radioiodine.
Comment: Cushing’s syndrome may present with spontaneous fractures in both axial and appendicular skeleton in the absence of marked clinical features. This case demonstrates the importance of thorough investigation of unexplained fractures.

LM Albon, JD Rippin & JA Franklyn

From http://www.endocrine-abstracts.org/ea/0005/ea0005p26.htm

Does a normal urine free cortisol result rule out Cushing’s syndrome?

ENDO_2015

 

March 07, 2015

SAT 379-412-Cushing’s Syndrome

Does a normal urine free cortisol result rule out Cushing’s syndrome?

ST Sharma, LK Nieman

Summary: Researchers conducted this study to assess the diagnostic accuarcy of urine free cortisol (UFC) and 24-hour urine 17-hydroxycorticosteroids (170HCS) in patients with Cushing’s syndrome, concluding that in patients with mild CS, UFC can be falsely normal or only minimally elevated. Further, they found that to help in making a diagnosis and prevent treatment delays, clinicians may consider incorporating multiple collections and use of complimentary screening tests including 24-hour urine 17OHCS and late night salivary cortisol (LNSC) testing.

Methods:

  • For this retrospective study, researchers included all CS patients evaluated at the National Institutes of Health (NIH) from 2009 to 2014.
  • The screening tests used for CS included UFC, 17OHCS, midnight serum cortisol and low dose (1 mg overnight or 2-day 2 mg/day) dexamethasone suppression test (DST).
  • They defined abnormal as values above reference range for UFC, 17OHCS and LNSC, a midnight serum cortisol ≥7.5 mcg/dL, and post-dexamethasone cortisol values ≥1.8 mcg/dL.
  • Hourly 24-hour sampling for cortisol was performed in a few cases with a mild clinical phenotype and equivocal test results.
  • Researchers measured UFC using liquid chromatography/tandem mass spectrometry (LC-MS/MS), and 17OHCS was measured using colorimetric methodology with Porter-Silber reaction (reported as mg/g of creatinine).
  • For this study, they used the mean of the first two UFC and 17OHCS values (appropriate collection by urine volume and creatinine) obtained within 30 days of initial NIH presentation.

Results:

  • In all, 72 patients were diagnosed with CS (aged 18-77 years, 51 females), 51 of whom had CD, 10 had ectopic CS, and 2 had an adrenal source of Cushing’s based on pathology.
  • Biochemical tests such as inferior petrosal sinus sampling (IPSS) suggested ectopic CS, but no tumor was found (occult) in 6 patients.
  • In 2 patients with failed transsphenoidal surgery, IPSS was indicative of a pituitary source, and one patient did not complete evaluation for ACTH-dependent CS.
  • UFC results were available in all patients, 17OHCS in 70, LNSC in 21, midnight serum cortisol in 68, and DST results in 37 patients.
  • UFC was falsely normal in 6 patients and only minimally elevated (<2 x ULN) in 13 patients (normal renal function, no history of cyclicity, all had CD); of these 19 patients, 24-hour 17OHCS was abnormal in all, LNSC was abnormal in 12, midnight serum cortisol was abnormal in 18, and DST was abnormal in 12 patients.
  • Hourly 24-hour sampling for cortisol performed in 3 of these patients revealed abnormal nadir (>7.5 mcg/dL) and mean daily serum cortisol (>9 mcg/dL) levels.

From http://www.mdlinx.com/endocrinology/conference-abstract.cfm/ZZ5BA369FDE9DE4CED82CB6A7CD5BFD1BE/42581/?utm_source=confcoveragenl&utm_medium=newsletter&utm_content=abstract-list&utm_campaign=abstract-ENDO2015&nonus=0

Exophthalmos and Cushing’s Syndrome

A woman experienced red, irritated and bulging eyes. She saw an ophthalmologist who strongly suspected Graves’ ophthalmopathy. However, the patient did not have and never had hyperthyroidism.

Indeed, she had primary hypothyroidism optimally treated with levothyroxine. Her thyroid stimulating hormone level was 1.197 uIU/mL.

An MRI of the orbits showed normal extraocular muscles without thickening, but there was mild proptosis and somewhat increased intraorbital fat content. Both thyroid-stimulating immunoglobulins as well as thyrotropin receptor antibodies were negative.

The patient presented to her primary care physician a few months later. She had experienced a 40-lb weight gain over only a few months and also had difficult-to-control blood pressure.

After failing to respond to several antihypertensive medications, her primary care physician astutely decided to evaluate for secondary causes of hypertension. A renal ultrasound was ordered to evaluate for renal artery stenosis, and the imaging identified an incidental right-sided adrenal mass. A CT confirmed a 3.4-cm right-sided adrenal mass. Her morning cortisol was slightly high at 24.7 ug/dL (4.3 – 22.4) and her adrenocorticotropic hormone was slightly low at 5 pg/mL (10-60).

At this point I saw the patient in consultation. She definitely had many of the expected clinical exam findings of Cushing’s syndrome, including increased fat deposition to her abdomen, neck, and supraclavicular areas, as well as striae. Her 24-hour urine cortisol was markedly elevated at 358 mcg/24hrs (< 45) confirming our suspicions.

She asked me, “Do you think that my eye problem could be related to this?”

“I’ve not heard of it before,” I replied, “but that doesn’t mean there can’t be a connection. Wouldn’t it be wonderful if your eyes got better after surgery?”

The patient underwent surgery to remove what fortunately turned out to be a benign adrenal adenoma.

When we saw her in follow-up 2 weeks later, her blood pressures were normal off medication and her eye symptoms had improved. I had a medical student rotating with me, so I suggested that we do a PubMed literature search.

The first article to come up was a case report titled “Exophthalmos: A Forgotten Clinical Sign of Cushing’s Syndrome.” Indeed, not only did Harvey Cushing describe this clinical finding in his original case series in 1932, but others have reported that up to 45% of patients with active Cushing’s syndrome have exophthalmos.

The cause is uncertain but is theorized to be due to increased intraorbital fat deposition. Unlike exophthalmos due to thyroid disease, the orbital muscles are relatively normal — just as they were with our patient.

Some of you may have seen exophthalmos in your Cushing’s patients; however, this was the first time I had seen it. Just because one has not heard of something, does not mean it could never happen; no one knows everything. “When in doubt, look it up” is a good habit for both attending physicians and their students.

For more information:

Giugni AS, et al. Case Rep Endocrinol. 2013; 2013: 205208.

From http://www.healio.com/endocrinology/adrenal/news/blogs/%7B779bf3e5-e1da-459e-af27-955c9b4274a5%7D/thomas-b-repas-do-facp-face-cde/exophthalmos-and-cushings-syndrome

Myth: UFC’s are the Gold Standard for Cushing’s testing

Myth: UFC’s are the Gold Standard for Cushing’s testing

myth-busted

Fact: UFC stands for Urinary Free Cortisol. In layman’s terms this test assesses cortisol by collecting urine for 24 hours. It was once thought that this was the gold standard and the end all and be all in terms of assessing Cushing’s in a patient. What we now know is that this is not necessarily true. Though this test is helpful in assessing for Cushing’s in some patients, not all patients have positive labs with this test, even if they DO, in fact, have Cushing’s.

There are various theories as to why. Cyclical Cushing’s patients also tend to report having a lower prevalence of positive UFCs in their test batteries.

Cushing’s experts understand that the most effective way to test for Cushing’s, especially in cases where it is suspected that the patient is cycling, is to administer multiple test measures across an extended period of time.

The following links may be helpful:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2978784/

Click to access LimitationsSC_UFC_dex_mildCS.pdf

http://survivethejourney.blogspot.com/2008/08/when-gold-standard-becomes-tarnished.html

Interview May 7 with Kathy C, Pituitary Patient

My name is Kathy Casey. I am a 63 year old retired school nurse. I am married with two wonderful sons and a grandson. My husband and I live in the mountain town of Mt. Shasta in northern California. I have always been athletic.

In 1995, I was diagnosed with a pituitary tumor. At the time the only symptom I was aware of was a severe headache. I had a transphenoidal resection by Dr. Wilson at UCSF Medical Center followed by radiation therapy for 23 days. At the time they said they could not remove all of the tumor.

In 2008/2009. I exhibited symptoms of Cushing’s and my cortisol level was outrageous, and I had to be hospitalized initially for a potassium level of 2. I returned to UCSF and Dr. Anwar Sandeep operated . By removing part of the tumor. My Cushing symptoms resolved. However, he said that the tumor was not encapsulated and was invading the cavernous sinus and stella turcica so it was still not possible to remove it all.

I was OK until December 2013 when I began exhibiting the symptoms of Cushings. One of my 24 hr. urines was 14,000. I had to be hospitalized for a potassium level of 1.9. Dr. Heaney said he has never seen a cortisol level that high. This time I decided to go to the UCLA Pituitary Tumor and Endocrinology Program where they were more oriented to follow-up and treating this disorder. Dr. Bergsneider decided that surgery was not an option. He and Dr. Heaney decided radiation was not an option. So now I am being followed by Dr. Heaney to see if medication can help.

I am now on Cabergoline 0.5 mg three tabs twice a week and Signifor 0.9 mg subcutaneosly twice a day. I think they are alleviating some of the symptoms. However, the Signifor caused my blood sugar to rise, and I had to go on Metformin which is causing nausea to a point where I have a hard time eating.

Anyway, this whole situation is depressing and overwhelming. I am tryng to stay positive, but I wonder how it will turn out. I am fortunate to have a supportive and helpful husband.

I am interested in communicating with people who may be going through a similar experience and learning more about this rare condition.

Kathy will be interviewed May 7, 2014 in BlogTalkRadio

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