Inferior Laryngeal Nerve Paraganglioma With Norepinephrine Hypersecretion Diagnosed Shortly After Pregnancy.

The diagnosis of pheochromocytoma or paraganglioma (PGL) during pregnancy is extremely rare, with 2 large case series suggesting that the prevalence is between 0.0002% and 0.007%. Here, we present a case of a 38-year-old woman who presented during pregnancy with clinical features suggestive of preeclampsia and was found to have a norepinephrine-secreting inferior laryngeal nerve PGL, which was diagnosed after pregnancy. She underwent uncomplicated surgical resection and genetic testing revealed a succinate dehydrogenase subunit B (SDHB) pathogenic variant. In conclusion, PGLs diagnosed during pregnancy and hypersecreting head and neck PGLs are both rare clinical entities. Hyperfunctioning PGLs may mimic pregnancy-induced hypertension or preeclampsia. Metanephrine testing should be considered in patients with atypical features and can be reliably assessed using nonpregnant reference ranges. Overall, maternal and fetal mortality has improved considerably with early diagnosis and treatment.

Ectopic Cushing's syndrome from an ACTH-producing pheochromocytoma with a non-functioning pituitary adenoma.

Summary: An adrenocorticotropic hormone (ACTH)-producing pheochromocytoma (PCC)/paraganglioma is the cause of ectopic Cushing's syndrome (CS) in 5.2% of cases reported in the literature. We present a previously healthy 43-year-old woman admitted to our hospital with cushingoid features and hypertensive urgency (blood pressure = 200/120 mmHg). Her 24-h urinary free cortisol was >4270 nmol/day (reference range (RR) = 100-380 nmol/day) with a plasma ACTH of 91.5 pmol/L (RR: 2.0-11.5 pmol/L). Twenty-four-hour urinary metanephrines were increased by 30-fold. Whole-body CT demonstrated a 3.7-cm left adrenal mass with a normal-appearing right adrenal gland. Sellar MRI showed a 5-mm sellar lesion. MIBG scan revealed intense uptake only in the left adrenal mass. She was managed pre-operatively with ketoconazole and phenoxybenzamine and underwent an uneventful left laparoscopic adrenalectomy, which resulted in biochemical resolution of her hypercortisolemia and catecholamine excess. Histology demonstrated a PCC (Grading System for Adrenal Pheochromocytoma and Paraganglioma score 5) with positive ACTH staining by immunohistochemistry. A PCC gene panel showed no mutations and there has been no evidence of recurrence at 24 months. This case highlights the difficult nature of localizing the source of CS in the setting of a co-existing PCC and sellar mass. Learning points: An adrenocorticotropic hormone (ACTH)-producing pheochromocytoma (PCC) is an important item to be considered in all patients presenting with ectopic Cushing's syndrome (CS). In exceptionally rare cases, patients with ectopic CS may present with multiple lesions, and a systematic approach considering all potential sources is crucial to avoid misdiagnosis. CS with a large adrenal mass but lacking contralateral adrenal atrophy should raise suspicion of an ACTH-dependent process. In patients with clinical suspicion of PCC, clinicians should be mindful of the use of steroids and beta-blockers without appropriate alpha blockade as they may precipitate an adrenergic crisis.

Carbamazepine drug effect simulating biochemical central hypothyroidism in a patient with Bardet-Biedl syndrome.

Carbamazepine (CBZ) is a medication used commonly in epilepsy. Decreases in free T4 levels simulating central hypothyroidism have been reported, although the clinical significance is still unclear. We present a 24-year-old man with Bardet-Biedl syndrome (BBS) who was found to have isolated biochemical central hypothyroidism. BBS is a ciliopathy occasionally associated with anterior pituitary dysfunction. While taking CBZ for epilepsy, his TSH was 1.73 mIU/L (reference range: 0.20-4.00 mIU/L) with a low free T4 of 6.6 pmol/L (reference range: 10.0-26.0 pmol/L). Pituitary MRI was normal. Although treated with levothyroxine initially, his apparent biochemical central hypothyroidism was later recognised as secondary to CBZ drug effect. This was confirmed with a normal free T4 of 12.2 pmol/L while he was off CBZ and levothyroxine. Despite the association between CBZ and biochemical central hypothyroidism, nearly all patients remain clinically euthyroid. This effect is reversible and recognition could lead to reductions in unnecessary thyroid replacement therapy if CBZ is discontinued.