Paradoxical response to dexamethasone and spontaneous hypocortisolism in Cushing's disease

Paradoxical response to dexamethasone and spontaneous development of hypocortisolism are rare features of Cushing's disease. We report a 13-year-old boy with Cushing's disease owing to a pituitary macroadenoma. On initial evaluation, he had partial suppression of serum cortisol by dexamethasone. He developed transient hypocortisolism after first adenomectomy, but the disease recurred after 1 year. Repeat evaluation showed recurrent hypercortisolism and paradoxical response to dexamethasone. He underwent second surgery and, postoperatively, hypercostisolism persisted even after 2 years of surgery. Repeat evaluations after 8 years of second surgery revealed persistent hypocortisolism despite residual tumour of same size and similar plasma adrenocorticotropic hormone (ACTH) levels. We have also shown that the paradoxical increase in serum cortisol was preceded by a paradoxical increase in ACTH. The paradoxical response persisted despite hypocortisolism. This patient with Cushing's disease had two very rare features: paradoxical response to dexamethasone and spontaneous development of hypocortisolism.

Aortoarteritis: Could it be a form of catecholamine-induced vasculitis?

Catecholamine-induced vasculitis is a well known but rarely described entity. However, aortoarteritis as a manifestation of catecholamine-induced vasculitis is not described in the literature. We have reported two patients in whom pheochromocytoma coexisted with aortoarteritis. Both patients were young females with history of bilateral pheochromocytomas in more than one first-degree relative. Both patients also had bilateral adrenal pheochromocytomas (second patient also had paraganglioma at left renal hilum) with elevation of plasma free normetanephrine levels. We conclude that there may be an association between pheochromocytoma and aortoarteritis, and that catecholamine excess may have a role in the etiopathogenesis of aortoarteritis in these patients.

Vanishing tumor in pregnancy

A patient with microprolactinoma, who had two successful pregnancies, is described for management issues. First pregnancy was uneventful. During the second pregnancy, the tumor enlarged to macroprolactinoma with headache and blurring of vision which was managed successfully with bromocriptine. Post delivery, complete disappearance of the tumor was documented.

Coexistence of pheochromocytoma/praganglioma and renal artery stenosis

Renal artery stenosis (RAS) often coexists with pheochromocytoma (Pheo)/paraganglioma (PGL) and often alters the management of patients with Pheo/PGL. We have studied the prevalence of RAS in our Pheo/PGL patients. The study included 70 consecutive, histopathologically proven Pheo/PGL patients from a tertiary health care center. In 60 patients, tumors were limited to adrenal glands (54 unilateral and 6 bilateral) while other 10 patients had extra-adrenal abdominal tumors. Five patients had RAS with an overall prevalence of 14%. Only two out of 60 patients with Pheo had RAS with a low prevalence of 3.3% while three out of 10 patients with extra-adrenal abdominal PGL had RAS with a prevalence of 30%. To conclude, RAS commonly coexists with Pheo/PGL, more often with extra-adrenal PGL.

Hyperphagic short stature: A case report and review of literature

A 5½-year-old adopted girl was referred to us in view of short stature. After ruling out systemic illness, she was evaluated for growth hormone deficiency (GHD) by stimulation tests. The peak value was 3.47 ng/ml. She was then started on growth hormone (GH). At the end of 6 months of GH therapy, her height velocity was only 3 cm/year. There was a lack of attachment between the mother and the child. She had history of hyperphagia, stealing, and hoarding food. Psychiatry consultation confirmed that the child had appetite disorder, and hence was diagnosed as hyperphagic short stature (HSS). The girl and her parents are undergoing psychiatric therapy for the same. Psychosocial dwarfism seems to originate from serious disturbances in the mother-child relationship. These children mimic patients with GHD, but have poor response to GH therapy. This case underscores the importance of social environment in the growth of the individual.

Ectopic posterior pituitary and stalk abnormality predicts severity and coexisting hormone deficiencies in patients with congenital growth hormone deficiency

Certain pituitary imaging abnormalities are a specific indicator of hypopituitarism. The objective of this study is to compare phenotypical features with radiological findings in patients with congenital growth hormone deficiency (GHD). Magnetic Resonance imaging (MRI) was performed in 103 patients [72 with Isolated GHD (IGHD) and 31 with Combined Pituitary Hormone Deficiency (CPHD)]. Images were assessed for the following abnormalities: (1) small/absent anterior pituitary, (2) thin or interrupted pituitary stalk (PSA), and (3) Ectopic posterior pituitary (EPP), and (4) others. Radiological findings were correlated with the clinical and biochemical parameters. MRI abnormalities were observed in 48.6% patients with IGHD, 93.5% with CPHD. Jaundice, hypoxia, hypoglycemia and breech deliveries were more common in EPP/PSA group. EPP/PSA was observed in 87.1% patients with severe GHD (peak GH < 3 μg/L) as compared to 12.9% with mild to moderate GHD (peak GH: 3-10 μg/L). Amongst CPHD, EPP/PSA was present in 80% of subjects with associated hypocortisolism ± hypothyroidism as compared to 18.2% of subjects with hypogonadism. Over a mean follow up period of 4.5 years, 5.4% of subjects with IGHD and abnormal MRI progressed to CPHD while none of those with normal MRI progressed. This study emphasizes a significant clinico-radiological correlation in Asian Indian GHD patients. MRI abnormalities in the hypothalamic pituitary area, especially EPP/PSA are more common in patients with CPHD and severe GHD. Among CPHD, EPP/PSA predicts association with hypothyroidism or hypocortisolism. IGHD with MRI abnormality may evolve into CPHD.

Peak bone mineral density and its determinants in an Asian Indian population

Data on peak bone mineral density (BMD) and its determinants in Asian Indians are limited. We studied the peak BMD and its determinants in Asian Indians. A total of 1137 young (age: 25--35yr) healthy volunteers of either sex (558 men and 579 women) were recruited for dietary evaluation, analyses of serum calcium, inorganic phosphorus, alkaline phosphatase, 25-hydroxyvitamin D [25(OH)D], and intact parathyroid hormone (iPTH) levels, and measurement of BMD with dual-energy X-ray absorptiometry. In men and women, peak bone mass (PBM) at the femoral neck, femoral trochanter, total femur, and lumbar spine was achieved between 25 and 30yr of age, whereas PBM at the femoral intertrochanter occurred between 30 and 35yr of age. Peak BMD was lower than that of Caucasians by 15.2--21.1% in men and 14.4--20.6% in women. On stepwise multiple regression, height and weight were the most consistent predictors of BMD at all sites in both groups. In men, 25(OH)D positively predicted BMD at the hip, whereas in women, serum iPTH negatively predicted BMD at the femoral trochanter and total femur. The study concluded that Asian Indians have significantly lower peak BMD than Caucasians and that weight and height are the most consistent predictors of BMD at all sites in both men and women.

Hypophosphatemic rickets

Hypophosphatemic rickets is a disorder of bone mineralization caused due to defects (inherited/acquired) in the renal handling of phosphorus. This group includes varied conditions, X-linked hypophosphatemic rickets being the most common inheritable form of rickets. The other common forms are autosomal dominant hypophosphatemic rickets and tumor-induced osteomalacia. Although these conditions exhibit different etiologies, increased phosphatonins form a common link among them. Fibroblast growth factor 23 (FGF23) is the most widely studied phosphatonin. Genetic studies tend to show that the phosphorus homeostasis depends on a complex osteo-renal axis, whose mechanisms have been poorly understood so far. Newer disorders are being added as the mechanisms in this axis get discovered. This review focuses on the clinical, biochemical, genetic features and management of hypophosphatemic disorders leading to defective mineralization.

Cushing disease in children and adolescents: twenty years' experience in a tertiary care center in India

OBJECTIVE

To analyze the clinical presentation, diagnostic evaluation, treatment modalities, and follow-up of pediatric patients with Cushing disease.

METHODS

In this retrospective analysis, we reviewed records of children (younger than 20 years) with Cushing disease who had undergone transsphenoidal adenomectomy in a tertiary health care center in India during the period of 1988 to 2008. Endogenous hypercortisolism was identified by a serum cortisol value ≥1.8 μg/dL during a low-dose dexamethasone suppression test (LDDST) with or without elevated midnight serum cortisol (≥3.2 μg/dL). Corticotropin dependence was defined by a basal plasma corticotropin concentration ≥5 pg/mL. Patients with normal pituitary imaging underwent bilateral inferior petrosal sinus sampling (BIPSS). Those with persistent or recurrent disease after surgery were treated with second-line interventions on a case-by-case basis.

RESULTS

Twenty-nine boys and 19 girls were included. Mean age was 14.85 (±2.5) years. Weight gain (98%), round facies (98%), and growth arrest (83%) were the most common manifestations. LDDST and midnight cortisol had 100% sensitivity for detecting endogenous hypercortisolism, while midnight corticotropin measurement had 100% sensitivity for defining corticotropin dependence. Magnetic resonance imaging and unstimulated BIPSS had 71% and 89% sensitivity, respectively, for diagnosing Cushing disease. Twenty-seven patients (56%) achieved remission after the first transsphenoidal operation with higher remission rates in those with microadenoma (75%). Basal serum cortisol <5 mg/dL on the fifth postoperative day predicted cure. Eight patients received postoperative radiotherapy, with 4 achieving remission.

CONCLUSIONS

Clinical presentation and diagnostic yield with various tests were similar to those previously reported in the literature. Remission rates were poor after first transsphenoidal operation in patients with macroadenoma and outcome was dismal with a second transsphenoidal operation. Serum cortisol concentration <5 mg/dL on the fifth postoperative day predicted cure.

Cushing's syndrome: Stepwise approach to diagnosis

The projected prevalence of Cushing's syndrome (CS) inclusive of subclinical cases in the adult population ranges from 0.2-2% and it may no longer be considered as an orphan disease (2-3 cases/million/year). The recognition of CS by physicians is important for early diagnosis and treatment. Late-night salivary cortisol, dexamethasone suppressiontesti, or 24-h urine free cortisol are good screening tests. Positively screened cases need stepwise evaluation by an endocrinologist. This paper discusses the importance of screening for CS and suggests a stepwise diagnostic approach to a case of suspected hypercortisolism.

Tumor-induced osteomalacia: a single center experience

OBJECTIVE

To describe the clinical presentation, localization modalities, and management of patients with tumor-induced osteomalacia (TIO).

METHODS

We performed a retrospective analysis of case records of patients diagnosed with TIO between January 1996 and March 2010 at our institution in Mumbai, India.

RESULTS

Nine patients (6 female and 3 male) with a mean age of 37.5 ± 17.5 years with biochemical and imaging evidence of TIO were included in the study. Overall, patients presented with proximal muscle weakness and pain. Three patients had neurofibromatosis 1, one had isolated schwannoma, and one had epidermal nevus syndrome. The mean delay in diagnosis was 7.67 years. Biochemical studies revealed normal serum calcium (mean, 9.2 ± 0.8 mg/dL), low serum phosphorus (mean, 1.36 ± 0.54 mg/dL), and low maximal tubular reabsorption of phosphorus factored for glomerular filtration rate (mean, 0.94 ± 0.49 mg/dL). Fibroblast growth factor-23 was increased in 3 of the patients without neurofibromatosis but was normal or near-normal in all the patients with neurofibromas. A fludeoxyglucose F 18 positron emission tomography (FDG PET) scan helped to localize the tumors in 4 of the 5 patients with diagnoses other than neurofibromatosis. Three patients underwent surgical excision and were cured. One patient underwent biopsy and partial excision. Histopathologic findings were suggestive of phosphaturic mesenchymal tumor, benign fibrous histiocytoma, nonossifying fibroma, and sciatic nerve schwannoma.

CONCLUSION

There is a well-known delay in the diagnosis of TIO. FDG PET is a useful modality for localization of tumors. Preoperative localization increases the odds for cure after surgical excision.

Prevalence and impact of thyroid disorders on maternal outcome in asian-Indian pregnant women

Aims. To establish the prevalence and the effect of thyroid dysfunction on pregnancy outcomes in Asian-Indian population. Subjects and Methods. The study cohort comprised of 483 consecutive pregnant women in the first trimester attending the antenatal clinic of a tertiary center in Mumbai, India. Thyroid hormone levels and thyroid peroxidase antibody were estimated. Patients with thyroid dysfunction were assessed periodically or treated depending on the severity. Subjects were followed until delivery. Results. The prevalence of hypothyroidism, Graves' disease, gestational transient thyrotoxicosis, and thyroid autoimmunity (TAI) was 4.8% (n = 24), 0.6% (n = 3), 6.4 % (n = 31), and 12.4% (n = 60), respectively. Forty percent of the hypothyroid patients did not have any high-risk characteristics. Hypothyroidism and TAI were associated with miscarriage (P = 0.02 and P = 0.001, resp.). Conclusions. The prevalence of hypothyroidism (4.8%) and TAI (12.4%) is high. TAI and hypothyroidism were significantly associated with miscarriage.

Prevalence of upper airway obstruction in patients with apparently asymptomatic euthyroid multi nodular goitre

AIMS

To study the prevalence of upper airway obstruction (UAO) in "apparently asymptomatic" patients with euthyroid multinodular goitre (MNG) and find correlation between clinical features, UAO on pulmonary function test (PFT) and tracheal narrowing on computerised tomography (CT).

MATERIALS AND METHODS

Consecutive patients with apparently asymptomatic euthyroid MNG attending thyroid clinic in a tertiary centre underwent clinical examination to elicit features of UAO, PFT, and CT of neck and chest.

STATISTICAL ANALYSIS USED

Statistical analysis was done with SPSS version 11.5 using paired t-test, Chi square test, and Fisher's exact test. P value of <0.05 was considered to be significant.

RESULTS

Fifty-six patients (52 females and four males) were studied. The prevalence of UAO (PFT) and significant tracheal narrowing (CT) was 14.3%. and 9.3%, respectively. Clinical features failed to predict UAO or significant tracheal narrowing. Tracheal narrowing (CT) did not correlate with UAO (PFT). Volume of goitre significantly correlated with degree of tracheal narrowing.

CONCLUSIONS

Clinical features do not predict UAO on PFT or tracheal narrowing on CT in apparently asymptomatic patients with euthyroid MNG.

Efficacy of cabergoline in uncured (persistent or recurrent) Cushing disease after pituitary surgical treatment with or without radiotherapy

OBJECTIVE

To evaluate the efficacy of cabergoline therapy in patients with Cushing disease who remained uncured (had persistent or recurrent disease) after a pituitary surgical procedure with or without radiotherapy.

METHODS

We undertook a prospective, open-label, single-arm study, with short-term (5 months) and longterm (1 year) evaluations. In 20 patients with uncured Cushing disease, treatment was initiated with cabergoline at a dosage of 1 mg/wk, with a monthly increment of 1 mg, until midnight serum cortisol (MNSC) or low-dose dexamethasone suppression serum cortisol (LDSC) (or both) normalized or a maximal dosage of 5 mg/wk was reached.

RESULTS

Overall, 5 of 18 patients (28%) responded in terms of LDSC or MNSC (or both) at a mean dosage of 3.6 mg/wk (range, 2 to 5). When the response was defined with use of either LDSC or MNSC level as an isolated criterion, it was achieved in 4 of 16 patients (25%) and 3 of 18 patients (17%), respectively. Four patients were treated for 1 year, and the response was persistent in 2 and 3 patients on the basis of MNSC and LDSC levels, respectively. Lower baseline serum cortisol (basal, MNSC, and LDSC) values were predictive of a therapeutic response.

CONCLUSION

Cabergoline was an effective therapy in 28%, 25%, and 17% of patients with uncured Cushing disease in terms of LDSC or MNSC (or both), LDSC alone, and MNSC alone, respectively. Further studies are needed to address the persistence of the drug response and the effects on the dynamics of the hypothalamic-pituitary-adrenal axis.

Pheochromocytoma and pregnancy: a rare but dangerous combination

OBJECTIVE

To review the literature on pheochromocytoma in pregnancy (PIP) published during the 11-year period 1998 through 2008.

METHODS

We searched MEDLINE data sources from 1998 through 2008 using the search terms "pheochromocytoma" and "pregnancy" and reviewed case reports of PIP published in English.

RESULTS

We identified 54 case reports in MEDLINE data sources, of which 51 reports including 60 cases were reviewed. In comparison with the previous decade, a decreased rate of antenatal diagnosis (from 83% to 70%) and increased maternal and fetal mortality (from 4% to 12% and from 10% to 17%, respectively) were observed. Prematurity was present in 53% of the infants of mothers with antenatally diagnosed pheochromocytoma who gave birth to a live infant. Hypertension was the most common manifestation (88%), with 33% of patients having antepartum hypertensive crises. Urinary catecholamines (64%) and metanephrines (40%) were the most commonly used tests, whereas urinary and plasma metanephrines were the most sensitive tests (100%). Ultrasonography had poor sensitivity (54%), especially during the third trimester. Magnetic resonance imaging was 100% sensitive for adrenal tumors but had only 50% sensitivity for extra-adrenal tumors. A syndromic or familial presentation was seen in 18% of patients, and 32% of patients had bilateral or extra-adrenal tumors.

CONCLUSION

In comparison with the previous decade, a decreased rate of antenatal diagnosis and increased maternal and fetal mortality were observed. Prematurity was a major morbidity associated with PIP. Hypertensive crises were more common during pregnancy. Urinary and plasma metanephrines had the highest sensitivity to detect PIP. Genetic screening should be offered to all pregnant women with pheochromocytoma.

Diagnostic efficacy of midnight cortisol and midnight ACTH in the diagnosis and localisation of Cushing's syndrome

Classical tests for diagnosis of Cushing's syndrome (CS) like urine free cortisol and dexamethasone suppression tests have limitations in various clinical settings. This study evaluated the usefulness of sleeping midnight serum cortisol (SMNC) as a diagnostic test for hypercortisolemia. A simultaneously done midnight plasma ACTH level was used to classify the disease as ACTH dependent or independent. Standard biochemical tests, SMNC, midnight plasma ACTH and appropriate imaging evaluated patients with a clinical suspicion of Cushing's syndrome. We evaluated 43 patients with CS comprising of 34 patients with Cushing's disease (CD), 2 patients with thymic carcinoid producing ectopic CS, 5 patients with adrenal carcinoma and 2 with adrenal adenoma. Thirteen patients with clinical suspicion were also evaluated with the above tests and CS was ruled out. SMNC, midnight plasma ACTH and dexamethasone suppressed cortisol was collected from patients with a suspicion of CS. SMNC was evaluated against histopathology as the gold standard. SMNC achieved 100% sensitivity in the diagnosis of endogenous CS at cut offs of 138 nmol/l and below. Raising the cut off to 207 nmol/l resulted in a test sensitivity of 90.5%. At a cut off of 1.65 pmol/l, midnight plasma ACTH could distinguish ACTH independent causes of CS with 100% sensitivity. We concluded that a single midnight collection could identify all patients with CS and classify the ACTH status at the proposed cut offs.