Context Paradoxical increases in serum cortisol in the dexamethasone suppression test (DST) have been rarely observed in Cushing’s disease (CD). Its pathophysiology and prevalence remain unclear. Case description A 62-year-old woman with suspected CD showed paradoxical increases in cortisol after both 1-mg and 8-mg DST (1.95-fold and 2.52-fold, respectively). The initiation of metyrapone paradoxically decreased plasma ACTH levels and suppressed cortisol levels. Moreover, the pituitary tumor considerably shrank during metyrapone treatment. Ex vivo experiments The resected tumor tissue was enzymatically digested, dispersed, and embedded into Matrigel as 3-D cultured cells. ACTH levels in the media were measured. In this tumor culture, ACTH levels increased 1.3-fold after dexamethasone treatment (p <0.01) while control tumor cultures exhibited no increase in ACTH levels, but rather 20–40% suppression (p <0.05). Clinical study A cross-sectional, retrospective, multicenter study that included 92 patients with CD who underwent both low dose- (LD) and high dose- (HD) DST from 2014 to 2020 was performed. Eight cases (8.7 %) showed an increase in serum cortisol after both LDDST and HDDST. Conclusions This is the first report of a patient with GC-driven positive-feedback CD who showed both ACTH suppression and tumor shrinkage by metyrapone. Our cohort study revealed that 8.7% of patients with CD patients possibly possess GC-driven positive feedback systems, thereby suggesting the presence of a new subtype of CD that is different from the majority of CD cases. The mechanisms exhibiting GC positive-feedback in CD and the therapeutic approach for these patients remain to be investigated.

A 77-year-old man was admitted to our hospital with femorofemoral bypass graft infection with methicillinresistant Staphylococcus aureus bacteremia. Following removal of the infected graft, intravenous vancomycin was administered. He became febrile again 19 days after surgery.Contrast-enhanced computed tomography (CT) showed a giant saccular aneurysm (10.5×6.2×6.5 cm) with luminal thrombus (Picture 1a, b). A smaller version of the same aneurysm (2.7×2.9×3.0 cm) was later observed on contrastenhanced CT performed at admission. Coronary angiogra-

Kenny–Caffey syndrome type 2 (KCS2) is an extremely rare skeletal disorder involving hypoparathyroidism and short stature. It has an autosomal dominant pattern of inheritance and is caused by variants in the FAM111 trypsin-like peptidase A (FAM111A) gene. This disease is often difficult to diagnose due to a wide range of more common diseases manifesting hypoparathyroidism and short stature. Herein, we present the case of a 56-year-old female patient with idiopathic hypoparathyroidism and a short stature. The patient was treated for these conditions during childhood. Upon re-evaluating the etiology of KCS2, we suspected that the patient had the disorder because of clinical manifestations, such as cortical thickening and medullary stenosis of the bones, and lack of intellectual abnormalities. Genetic testing identified a heterozygous missense variant in the FAM111A gene (p.R569H). Interestingly, the patient also had bilateral sensorineural hearing loss and vestibular dysfunction, which have been rarely described in previous reports of pediatric cases. In KCS2, inner ear dysfunction due to Eustachian tube dysfunction may progress in middle age or later. However, this disease is now being reported in younger patients. Nevertheless, our case may be instructive of how such cases emerge chronically after middle age. Herein, we also provide a literature review of KCS2.

A 21-year-old Japanese man without known diabetes mellitus had abdominal pain. The diagnosis was ketoacidosis and hypertriglyceridemia-induced acute pancreatitis. He had polydipsia and polyuria and had habitually drunk several soft drinks every day for two years. After hospitalization, despite adequate liquid intake, dehydration remained with hypotonic polyuria. Further examinations revealed the coexistence of central diabetes insipidus (CDI), possibly caused by lymphocytic infundibulo-neurohypophysitis, based on antirabphilin-3A antibody positivity. Although CDI had been undiagnosed for two years, over-consumption of sugar-rich soft drinks to ease thirst caused ketoacidosis, hypertriglyceridemia, and acute pancreatitis. There are no previous reports of this three-part combination of symptoms caused by CDI.

Pheochromocytoma is a rare but life-threatening condition due to catecholamine release induced by drug treatments such as β-blockers or glucocorticoids. We present a case of hypertensive crisis due to pheochromocytoma, induced after the initiation of dexamethasone and landiolol during intensive care for severe coronavirus disease 2019 (COVID-19). Based on a detailed medical history review, the patient was previously diagnosed with primary aldosteronism by confirmatory tests, moreover, an abdominal computed tomography scan identified an adrenal tumor 2 years before current admission. We tentatively diagnosed the patient with pheochromocytoma and initiated α-blockers without conducting a catecholamine report, leading to stable hemodynamics. We present a successfully managed case of pheochromocytoma concomitant with COVID-19, which has become a global crisis.