Coexistence of Cushing Disease With a Solitary Adrenocorticotrophic Hormone-Dependent Adrenal Adenoma

Objective

We report a 49-year-old woman who had minimal features of Cushing syndrome and an incidentally discovered adrenal adenoma. She was subsequently diagnosed with pituitary-dependent Cushing syndrome.

Methods

Laboratory and imaging studies including serum cortisol, plasma adrenocorticotrophic hormone (ACTH), high dose dexamethasone test, corticotropin-releasing hormone test, computed tomography (CT) scan, and magnetic resonance imaging were performed.

Results

A 49-year-old woman was admitted for urosepsis. An abdominal CT scan performed during the urosepsis workup showed a 2.7-cm right adrenal adenoma. She denied any abdominal striae or other symptoms. Physical examination showed normal vital signs, minimal facial fullness without central obesity, and striae. Laboratory results were as follows: 24-hour-urine cortisol 294 μg (reference 4.0-50.0), midnight serum cortisol 23.0 μg/dL (reference < 7.5), and plasma ACTH level 39 pg/mL (reference 5-27). A corticotropin-releasing hormone stimulation test showed >20% rise in serum cortisol and >35% rise in ACTH levels. A pituitary magnetic resonance image showed a 5 mm pituitary lesion. The patient underwent transsphenoidal pituitary surgery, which confirmed an ACTH-secreting lesion. Postoperatively, she required hydrocortisone replacement for the next 10 months. A follow-up adrenal CT performed 6 months later showed a decrease in the size of the adrenal adenoma (1.8 cm).

Conclusion

This case highlights the importance of recognizing the coexistence of ACTH-dependent Cushing disease with an adrenal adenoma and partial ACTH dependency of the adrenal adenoma.

Abnormal glucose tolerance in a patient with pheochromocytoma and ACTH-independent subclinical Cushing's syndrome involving the same adrenal gland

Coexistence of adrenocorticotropin hormone (ACTH)-independent subclinical Cushing’s syndrome (SCS) with pheochromocytoma involving the same adrenal tumor is rare. Moreover, no previous reports have compared pre- and postoperative insulin sensitivities in these cases. A 74-year-old woman was admitted to our hospital with hyperhidrosis, dry mouth, and weight loss. Pheochromocytoma was suspected based on elevated circulating catecholamines, and was confirmed by scintigraphy and histopathological analysis. Laboratory data, low ACTH, and lack of a diurnal cortisol rhythm indicated coexisting Cushing’s syndrome (CS). The atypical symptoms of CS and lack of cortisol suppression after 1 and 8 mg dexamethasone suppression tests confirmed the diagnosis of SCS. Histopathological analysis demonstrated autonomous cortisol production caused by paracrine stimulation from the pheochromocytoma. Her fasting plasma glucose level on admission was 372 mg/dL and her hemoglobin (Hb) A1c was 11.0%. HbA1c decreased to 5.2% postoperatively, with improved insulin secretion indicated by homeostasis model assessment β (18.1 to 45) and urinary C-peptide (26.5 to 48.5 mg/day). Herein we report a rare case of pheochromocytoma and SCS involving the same adrenal tumor, with the first documented levels of glucose tolerance before and after surgery. Coexisting SCS should thus be considered in patients with pheochromocytoma presenting with severely uncontrolled diabetes mellitus.

The 3PAs: An Update on the Association of Pheochromocytomas, Paragangliomas, and Pituitary Tumors

Pituitary adenomas (PA) and pheochromocytomas/paragangliomas (PHEO/PGL) are rare tumors. Although they may co-exist by coincidence, there is mounting evidence that genes predisposing in PHEO/PGL development, may play a role in pituitary tumorigenesis. In 2012, we described a GH-secreting PA caused by an SDHD mutation in a patient with familial PGLs and found loss of heterozygosity at the SDHD locus in the pituitary tumor, along with increased hypoxia-inducible factor 1α (HIF-1α) levels. Additional patients with PAs and SDHx defects have since been reported. Overall, prevalence of SDHx mutations in PA is very rare (0.3-1.8% in unselected cases) but we and others have identified several cases of PAs with PHEOs/PGLs, like our original report, a condition which we termed the 3 P association (3PAs). Interestingly, when 3PAs is found in the sporadic setting, no SDHx defects were identified, whereas in familial PGLs, SDHx mutations were identified in 62.5-75% of the reported cases. Hence, pituitary surveillance is recommended among patients with SDHx defects. It is possible that the SDHx germline mutation-negative 3PAs cases may be due to another gene, epigenetic changes, mutations in modifier genes, mosaicism, somatic mutations, pituitary hyperplasia due to ectopic hypothalamic hormone secretion or a coincidence. PA in 3PAs are mainly macroadenomas, more aggressive, more resistant to somatostatin analogues, and often require surgery. Using the Sdhb ^+/- mouse model, we showed that hyperplasia may be the first abnormality in tumorigenesis as initial response to pseudohypoxia. We also propose surveillance and follow-up approach of patients presenting with this association.

15 YEARS OF PARAGANGLIOMA: The association of pituitary adenomas and phaeochromocytomas or paragangliomas

The combination of pituitary adenomas (PA) and phaeochromocytomas (phaeo) or paragangliomas (PGL) is a rare event. Although these endocrine tumours may occur together by coincidence, there is mounting evidence that, in at least some cases, classical phaeo/PGL-predisposing genes may also play a role in pituitary tumorigenesis. A new condition that we termed '3Pas' for the association of PA with phaeo and/or PGL was recently described in patients with succinate dehydrogenase mutations and PAs. It should also be noted that the classical tumour suppressor gene, MEN1 that is the archetype of the PA-predisposing genes, is also rarely associated with phaeos in both mice and humans with MEN1 defects. In this report, we review the data leading to the discovery of 3PAs, other associations linking PAs with phaeos and/or PGLs, and the corresponding clinical and molecular genetics.