A stress sensor, IRE1α, is required for bacterial-exotoxin-induced interleukin-1ß production in tissue-resident macrophages.

Cholera toxin (CT), a bacterial exotoxin composed of one A subunit (CTA) and five B subunits (CTB), functions as an immune adjuvant. CTB can induce production of interleukin-1ß (IL-1ß), a proinflammatory cytokine, in synergy with a lipopolysaccharide (LPS), from resident peritoneal macrophages (RPMs) through the pyrin and NLRP3 inflammasomes. However, how CTB or CT activates these inflammasomes in the macrophages has been unclear. Here, we clarify the roles of inositol-requiring enzyme 1 alpha (IRE1α), an endoplasmic reticulum (ER) stress sensor, in CT-induced IL-1ß production in RPMs. In RPMs, CTB is incorporated into the ER and induces ER stress responses, depending on GM1, a cell membrane ganglioside. IRE1α-deficient RPMs show a significant impairment of CT- or CTB-induced IL-1ß production, indicating that IRE1α is required for CT- or CTB-induced IL-1ß production in RPMs. This study demonstrates the critical roles of IRE1α in activation of both NLRP3 and pyrin inflammasomes in tissue-resident macrophages.

Functional characterization of variants found in Japanese patients with hereditary hemorrhagic telangiectasia.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant form of vascular dysplasia. Genetic diagnosis is made by identifying loss-of-function variants in genes, such as ENG and ACVRL1. However, the causal mechanisms of various variants of unknown significance remains unclear. In this study, we analyzed 12 Japanese patients from 11 families who were clinically diagnosed with HHT. Sequencing analysis identified 11 distinct variants in ACVRL1 and ENG. Three of the 11 were truncating variants, leading to a definitive diagnosis, whereas the remaining eight were splice-site and missense variants that required functional analyses. In silico splicing analyses demonstrated that three variants, c.526-3C > G and c.598C > G in ACVRL1, and c.690-1G > A in ENG, caused aberrant splicing, as confirmed by a minigene assay. The five remaining missense variants were p.Arg67Gln, p.Ile256Asn, p.Leu285Pro, and p.Pro424Leu in ACVRL and p.Pro165His in ENG. Nanoluciferase-based bioluminescence analyses demonstrated that these ACVRL1 variants impaired cell membrane trafficking, resulting in the loss of bone morphogenetic protein 9 (BMP9) signal transduction. In contrast, the ENG mutation impaired BMP9 signaling despite normal cell membrane expression. The updated functional analysis methods performed in this study will facilitate effective genetic testing and appropriate medical care for patients with HHT.

Profiling of Unfolded Protein Response Markers and Effect of IRE1α-specific Inhibitor in Pituitary Neuroendocrine Tumor.

CONTEXT: Inositol-requiring enzyme 1α (IRE1α) and PKR-like ER kinase (PERK), which are endoplasmic reticulum (ER) membrane proteins, regulate the unfolded protein response (UPR). These molecules have recently gained attention as a novel therapeutic target in secretory tumors. The roles of the UPR in pituitary neuroendocrine tumors (PitNETs) are unclear. OBJECTIVE: To clarify UPR profiling of PitNETs and to investigate the effect of pharmacological modulation of UPR by KIRA8, a newly developed IRE1α-specific inhibitor. METHODS: In 131 patients with PitNETs, we evaluated RNA expression of UPR markers in PitNETs and their clinical phenotypes. Using GH3 cells, we examined the effects of KIRA8 and its combination with octreotide on UPR profiling, cell growth, and apoptosis. RESULTS: Cytoprotective adaptive-UPR (A-UPR) markers were more increased in functioning PitNETs (FPitNETs, n = 112) than in nonfunctioning PitNETs (NFPitNETs, n = 19), while there was no difference in proapoptotic terminal-UPR (T-UPR) markers. Similarly, overt somatotroph tumors (STs, acromegaly, n = 11) increased A-UPR compared with silent STs (n = 10). In STs, serum IGF-1 levels were inversely correlated with Txnip mRNA expression, a representative T-UPR marker. KIRA8 inhibited cell growth and facilitated apoptosis in GH3 cells with increased expressions of T-UPR markers, which was enhanced by the combination with octreotide. Octreotide increased mRNA expression of Txnip and Chop, but decreased spliced Xbp1 under ER stress. Octreotide is suggested to inhibit activation of IRE1α but to reciprocally induce T-UPR under PERK. CONCLUSION: UPR markers in FPitNETs are implicated as dominant A-UPR but blunted T-UPR. KIRA8, enhanced with octreotide, unbalances the UPR, leading to antitumor effects. Targeting IRE1α may provide a novel strategy to treat PitNETs.

Radical resection of intracavernous chondrosarcoma using an intradural keyhole approach: how I do it.

BACKGROUND: Skull base chondrosarcoma is rare, arising from the clivus or petroclival junction, and usually presents as ocular motility disorders. Endonasal transsphenoidal surgery may be performed in some cases of midline clivus chondrosarcoma. Chondrosarcoma is located within the cavernous sinus and presents a softer/gelatinous mass and can be removed with suctions and curettage. We have been using a simple intradural keyhole transcavernous approach, avoiding a complex extradural transcavernous dissection. METHODS: The intracavernous chondrosarcoma was removed via a 5 mm keyhole opening over the Parkinson's triangle using a standard frontotemporal intradural approach. CONCLUSION: Minimally invasive keyhole surgical resection can be performed to eradicate skull base chondrosarcomas, avoiding complex extradural cranial base approaches.

Validation of Efficacy and Safety of TachoSil ® Tissue Sealant for Vessel Transposition in Microvascular Decompression.

BACKGROUND AND OBJECTIVES: Use of TachoSil ® as the transposition material of microvascular decompression (MVD) for hemifacial spasm (HFS) and trigeminal neuralgia (TN) is easy and safe to perform, but the efficacy and safety of this technique are unknown. This study attempted to validate the efficacy and safety of TachoSil ® as a transposition material of MVD. METHODS: A retrospective study of the surgical results and complications of 63 patients (35 HFS and 28 TN) treated by the TachoSil ® technique between January 2011 and December 2021 was conducted. The efficacy of the treatment was evaluated by Kaplan-Meier survival analysis. Magnetic resonance imaging follow-up study was performed to detect any adverse events including a mass formation. RESULTS: The rate of complete disappearance of HFS was 91.4% at 1 year and estimated to be 85.7% after a 10-year follow-up. The rate of no pain without medication for TN was 85.4% at 1 year and estimated to be 69.0% after a 9-year follow-up. These surgical results are comparable with those previously reported. Flaking of TachoSil ® releasing the offending artery was only recognized in one case (1.6%). Therefore, TachoSil ® can be considered as an effective transposition material for MVD. TachoSil ® did not increase the rate of acute and subacute adverse events such as inflammation and delayed facial palsy. Magnetic resonance imaging follow-up identified no abnormalities including mass that suggested granuloma formation. CONCLUSION: The efficacy of the TachoSil ® technique for HFS and TN and the reliability of TachoSil ® as an adhesive material in MVD were verified. No adverse events associated with TachoSil ® use in MVD were found. We conclude that the TachoSil ® technique has relatively long efficacy and safety for MVD.

Renoprotective potential of concomittant medications with SGLT2 inhibitors and renin-angiotensin system inhibitors in diabetic nephropathy without albuminuria: a retrospective cohort study.

The renal protective effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors and renin-angiotensin system (RAS) inhibitors on diabetic nephropathy without albuminuria have not been fully investigated. This retrospective cohort study focused on patients with type 2 diabetes mellitus who had a baseline estimated glomerular filtration rate (eGFR) of > 30 mL/min/1.73 m2, and a urinary albumin-to-creatinine ratio < 30 mg/gCr. After propensity score matching, using covariates such as age, body mass index, systolic blood pressure, hemoglobin A1c levels, and prescription history of RAS inhibitors, we established a cohort of 58 patients: the SGLT2 inhibitor group (n = 28) and the control group (n = 28). In this cohort, we compared the annual eGFR decline rate between the two groups. The SGLT2 inhibitor group exhibited a significantly smaller eGFR change than the control group (- 1.15 vs. - 2.18 mL/min/1.73 m2/year). Within the SGLT2 inhibitor group, patients prescribed RAS inhibitors had demonstrated an even smaller eGFR change (- 0.70 mL/min/1.73 m2/year). In conclusion, SGLT2 inhibitors also have safeguarding effects in the stage of diabetic nephropathy without albuminuria, and the combined use of a SGLT2 inhibitor and a RAS inhibitor appears to be more effective than the single use of each.

Supraorbital keyhole approach for paraclinoid aneurysms clipping: A case series with literature review.

Background: Paraclinoid aneurysms (PcAs) are challenging aneurysms due to the complexity of their relation to the surrounding bony and neurovascular structures. Although over the past decade, their management strategy has shifted from transcranial to endovascular approaches; here, we try to revolve around a subcategory to which minimal invasive supraorbital keyhole (SOK) surgery is feasible depending on specific radiological criteria with a literature review. Methods: A group of unruptured PcAs was managed surgically, with a subset that was clipped through the SOK approach. They were selected by preoperative simulation images using 3D computed tomography (CT) angiography (CTA). We also conducted an extensive literature review based on a database available on PubMed and Google Scholar, the yielded cases from the literature review plus our cases were analyzed according to six parameters including their size, location, dome direction, need for clinoidectomy and proximal cervical control, and surgical outcome. Results: From February 2009 to August 2022, 49 cases of unruptured PcAs were managed by clipping, and of these, four cases were clipped by the SOK approach, in addition, four cases were yielded through the literature review. The sizes of the PcAs ranged from 3 to 8 mm. Their location fluctuated from anterior to the superomedial wall and their domes pointed superiorly except for one which points posteriorly. Six of eight cases required anterior clinoidectomy, the outcome was uneventful. Conclusion: A subset of unruptured PcAs are amenable to SOK with criteria such as unruptured small aneurysm (<10 mm) and projected superiorly. These characteristics can be determined preoperatively using CTA.

Amino acid polymorphisms in human histocompatibility leukocyte antigen class II and proinsulin epitope have impacts on type 1 diabetes mellitus induced by immune-checkpoint inhibitors.

Introduction: Immune-checkpoint inhibitors are effective in various advanced cancers. Type 1 diabetes mellitus induced by them (ICI-T1DM) is a serious complication requiring prompt insulin treatment, but the immunological mechanism behind it is unclear. Methods: We examined amino acid polymorphisms in human histocompatibility leukocyte antigen (HLA) molecules and investigated proinsulin epitope binding affinities to HLA molecules. Results and Discussion: Twelve patients with ICI-T1DM and 35 patients in a control group without ICI-T1DM were enrolled in the study. Allele and haplotype frequencies of HLA-DRB1*04:05, DQB1*04:01, and most importantly DPB1*05:01 were significantly increased in patients with ICI-T1DM. In addition, novel amino acid polymorphisms in HLA-DR (4 polymorphisms), in DQ (12 polymorphisms), and in DP molecules (9 polymorphisms) were identified. These amino acid polymorphisms might be associated with the development of ICI-T1DM. Moreover, novel human proinsulin epitope clusters in insulin A and B chains were discovered in silico and in vitro peptide binding assays to HLA-DP5. In conclusion, significant amino acid polymorphisms in HLA-class II molecules, and conformational alterations in the peptide-binding groove of the HLA-DP molecules were considered likely to influence the immunogenicity of proinsulin epitopes in ICI-T1DM. These amino acid polymorphisms and HLA-DP5 may be predictive genetic factors for ICI-T1DM.

Traumatic rupture of intracranial dermoid cyst with continuous fat droplet migration.

Background: The intracranial dermoid cyst (ICD) can be complicated by rupture and spilling of its contents with potentially dreadful consequences. Head trauma as a predisposing element for this phenomenon is extremely rare. Few reports address the diagnosis and management of trauma-related rupture of ICD. However, there is a pronounced knowledge gap related to the long-term follow-up and the fate of the leaking contents. Here, we present a unique case of traumatic rupture of ICD complicated by continuous fat particle migration within the subarachnoid space with its surgical implications and outcome. Case Description: A 14-year-old girl had an ICD rupture following a vehicle collision. The cyst was located near the foramen ovale with intra and extradural extensions. Initially, we opted to follow the patient clinically and radiologically as she had no symptoms, and the imaging showed no red flags. Over the next 24 months, the patient remained asymptomatic. However, the sequential brain magnetic resonance imaging revealed significant continuous migration of the fat within the subarachnoid space, with the droplets noticed to increase in the third ventricle. That is considered an alarming sign of potentially serious complications impacting the patient's outcome. Based on the above, the ICD was completely resected through an uncomplicated microsurgical procedure. On follow-up, the patient is well, with no new radiological findings. Conclusion: Trauma-related ruptured ICD may have critical consequences. Persistent migration of dermoid fat can be managed with surgical evacuation as a viable option to prevent those potential complications such as obstructive hydrocephalus, seizures, and meningitis.

Pheochromocytoma Multisystem Crisis Complicated by Severe Acute Pancreatitis.

A 43-year-old man developed headache, dizziness, abdominal pain, and vomiting. His blood pressure was 203/121 mmHg, heart rate 122 beats/min, body temperature 39.1°C, and respiratory rate 24/min. He had elevated levels of creatinine at 2.95 mg/dL and lipase at 1,364 U/L as well as an extremely low calcium level at 5.2 mg/dL. Hypertriglyceridemia and hyperglycemia were seen. Chest and abdominal computed tomography showed interstitial pneumonia, severe pancreatitis, and a right adrenal tumor. The patient also developed vertebral artery dissection and medullary infarction. After right adrenalectomy, the patient was diagnosed with pheochromocytoma multisystem crisis (PMC). Acute pancreatitis might augment numerous life-threatening manifestations of PMC.

Glioependymal cyst in the medulla oblongata - A case report.

Background: Glioependymal cysts (GECs) are rare benign lesions that can be found anywhere along the neuroaxis, with most of the reports denoting supratentorial location. Here, we introduce a rare case of successfully treated glioependymal cysts lying in an uncommon location, namely medulla oblongata. Case Description: A 69-year-old lady presented with progressive unsteadiness and swallowing disturbances, and brain magnetic resonance imaging showed a dorsally located lesion within the medulla oblongata; based on the presentation and radiological features, surgical intervention was deemed mandatory. The suboccipital midline approach was used to perform marsupialization of the cyst with shunting through a syringosubarachnoid shunt to prevent future recurrence, and the patient outcome was improved. Conclusion: Medulla Oblongata's location for glioependymal cysts proposed unique diagnostic and operative challenges that may require highlighting for practicing neurosurgeons.

Allosteric Inhibition of c-Abl to Induce Unfolded Protein Response and Cell Death in Multiple Myeloma.

Endoplasmic reticulum stress activates inositol-requiring enzyme 1α (IRE1α) and protein kinase, R-like endoplasmic reticulum kinase (PERK), the two principal regulators of the unfolded protein response (UPR). In multiple myeloma, adaptive IRE1α signaling is predominantly activated and regulates cell fate along with PERK. Recently, we demonstrated that GNF-2, an allosteric c-Abl inhibitor, rheostatically enhanced IRE1α activity and induced apoptosis through c-Abl conformational changes in pancreatic ß cells. Herein, we analyzed whether the pharmacological modulation of c-Abl conformation resulted in anti-myeloma effects. First, we investigated the effects of GNF-2 on IRE1α activity and cell fate, followed by an investigation of the anti-myeloma effects of asciminib, a new allosteric c-Abl inhibitor. Finally, we performed RNA sequencing to characterize the signaling profiles of asciminib. We observed that both GNF-2 and asciminib decreased cell viability and induced XBP1 mRNA splicing in primary human myeloma cells and myeloma cell lines. RNA sequencing identified the induction of UPR- and apoptosis-related genes by asciminib. Asciminib re-localized c-Abl to the endoplasmic reticulum, and its combination with a specific IRE1α inhibitor, KIRA8, enhanced cell death with the reciprocal induction of CHOP mRNA expression. Together, the allosteric inhibition of c-Abl-activated UPR with anti-myeloma effects; this could be a novel therapeutic target for multiple myeloma.

Hypopituitarism and cranial nerve involvement mimicking Tolosa-Hunt syndrome as the initially presenting feature of diffuse large B-cell lymphoma: a case report.

BACKGROUND: Early diagnosis of lymphoma involving the central nervous system is sometimes difficult but emergent to avoid the delay of therapeutic initiation. Pituitary insufficiencies are usually associated with lymphoma in the pituitary gland. There have been no cases of lymphoma originating from extra pituitary gland with hypopituitarism that simultaneously presenting unilateral upper cranial nerve palsies and ophthalmalgia. These symptoms are mostly caused by neoplastic involvement of the skull base or benign diseases such as Tolosa-Hunt syndrome (THS). We report a case of lymphoma with unique clinical courses initially presenting hypopituitarism and symptoms mimicking THS with a mass in sphenoidal and cavernous sinuses accompanying sphenoidal bone erosion. CASE PRESENTATION: A 71-year-old woman visited our hospital with left ophthalmalgia, ptosis, and diplopia. Neurological findings revealed left oculomotor, trochlear and abducent nerve palsies. Endocrine tests indicated partial hypopituitarism. Initial CT and MRI revealed that a mass in sphenoidal and cavernous sinuses had invaded the sella with osteolysis of the sphenoid bone. At around four weeks, almost all the symptoms of cranial nerve palsies were relieved. Seven weeks later, she had a high fever and cervical lymph node (CLN) swellings. CLN biopsy revealed CD20-positive B-cells. She was diagnosed with diffuse large B-cell lymphoma (DLBCL). 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) revealed elevated uptake at the erosion lesion of the sphenoidal bone, but not the pituitary gland. After chemotherapy, all the symptoms related to systemic lymphoma were relieved, but partial hypopituitarism remained. The mass in sphenoidal and cavernous sinuses and elevated uptake by PET/CT were dissolved. CONCLUSION: This case of DLBCL had a unique clinical course; initial presentation of hypopituitarism and symptoms mimicking THS. There was also rare demonstration of mass lesions related to DLBCL in the sphenoidal and cavernous sinuses compressing the pituitary gland through an eroded area of the sphenoidal bone. It should be clinically cautioned that DLBCL can be associated with erosion of the sphenoidal bone and cause both hypopituitarism and THS-mimicking symptoms.

Quantification of serum C-mannosyl tryptophan by novel assay to evaluate renal function and vascular complications in patients with type 2 diabetes.

C-Mannosyl tryptophan (CMW) is a unique glycosylated amino acid, and a candidate novel biomarker of renal function. In type 2 diabetes (T2D), a combination of metabolites including CMW has recently been the focus of novel biomarkers for the evaluation of renal function and prediction of its decline. However, previous quantification methods for serum CMW have several limitations. We recently established a novel assay for quantifying serum CMW. Serum CMW from 99 Japanese patients with T2D was quantified by this assay using hydrophilic interaction liquid chromatography. The serum CMW levels were cross-sectionally characterized in relation to clinical features, including renal function and vascular complications. Serum CMW level was more strongly correlated with serum creatinine and cystatin C levels and with eGFR than with albumin urea level. The ROC curve to detect eGFR < 60 ml/min/1.73 m2 revealed that the cutoff serum CMW level was 337.5 nM (AUC 0.883). Serum CMW levels were higher in patients with a history of macroangiopathy than in those without history. They correlated with ankle-brachial pressure index, whereas cystatin C did not. Serum CMW levels quantified by the novel assay could be useful in evaluation of glomerular filtration of renal function and peripheral arterial disease in T2D.

Early detection of euglycemic ketoacidosis during thoracic surgery associated with empagliflozin in a patient with type 2 diabetes: A case report.

We report the first case of intraoperatively detected euglycemic diabetic ketoacidosis (DKA) associated with sodium-glucose cotransporter 2 inhibitors during thoracic surgery. A 59-year-old man had a 12-year history of type 2 diabetes mellitus treated with insulin and empagliflozin. The patient developed bacterial empyema and was initiated with antibiotics at a local hospital. Owing to the persistence of his symptoms, he was transferred to our hospital after the medication of empagliflozin the day before surgery. After overnight fasting, the patient underwent thoracoscopic debridement and intrathoracic lavage surgery. During this surgery, he was noted to have euglycemic ketosis and acidosis, and diagnosed as euglycemic DKA. Immediately after the consultation in our department, the patient underwent treatment for DKA. He awoke from anesthesia normally and showed no symptoms of DKA. DKA gradually resolved over the next 24 h. Early identification and management are critical for rapid recovery from perioperative euglycemic DKA associated with sodium-glucose cotransporter 2 inhibitors, especially during thoracic surgery.

Distinct clinical features and prognosis between persistent and temporary thyroid dysfunctions by immune-checkpoint inhibitors.

Immune-related adverse events in the thyroid glands (thyroid irAEs) during treatment with immune-checkpoint inhibitors (ICIs) are most frequent endocrine irAE. Thyroid irAE can be divided into that requiring continuous therapy for thyroid dysfunction (P-THY), and that requiring only temporal treatment (T-THY). However, predictive factors for those differential outcomes are unknown, and susceptibility of human leukocyte antigen (HLA) to thyroid irAE has never been investigated. This study aimed to elucidate clinical courses and prognosis of P-THY in comparison with T-THY in the aspect of thyroid immunity and HLA. Patients with P-THY (n = 15) that required L-T4 supplemental therapy for hypothyroidism for more than 3 months, and patients with T-THY who required no therapy or therapy within 1 month were enrolled in the study. Lower-value of TSH, higher-value of FT4, and lower value of TSH/FT4 were thought to be predictive markers to estimate P-THY. In addition, anti-thyroglobulin antibody (TgAb) levels were significantly higher in patients with P-THY than those in patients with T-THY. HLA-DPA1*01:03 and HLA-DPB1*02:01 allele, and their haplotype frequencies were significantly higher in patients with P-THY than those in controls. P-THY had better survival rate than T-THY. Pre-existing thyroid autoimmunity, the extent of thyroid dysfunction, and predisposing HLA were associated with the differential course of thyroid irAEs. It was suggested that thyroid function tests, TgAb, and HLA typing tests are useful for prediction of clinical course in thyroid irAEs.

Targeting Adaptive IRE1α Signaling and PLK2 in Multiple Myeloma: Possible Anti-Tumor Mechanisms of KIRA8 and Nilotinib.

BACKGROUND: Inositol-requiring enzyme 1α (IRE1α), along with protein kinase R-like endoplasmic reticulum kinase (PERK), is a principal regulator of the unfolded protein response (UPR). Recently, the 'mono'-specific IRE1α inhibitor, kinase-inhibiting RNase attenuator 6 (KIRA6), demonstrated a promising effect against multiple myeloma (MM). Side-stepping the clinical translation, a detailed UPR phenotype in patients with MM and the mechanisms of how KIRA8 works in MM remains unclear. METHODS: We characterized UPR phenotypes in the bone marrow of patients with newly diagnosed MM. Then, in human MM cells we analyzed the possible anti-tumor mechanisms of KIRA8 and a Food and Drug Administration (FDA)-approved drug, nilotinib, which we recently identified as having a strong inhibitory effect against IRE1α activity. Finally, we performed an RNA-sequence analysis to detect key IRE1α-related molecules against MM. RESULTS: We illustrated the dominant induction of adaptive UPR markers under IRE1α over the PERK pathway in patients with MM. In human MM cells, KIRA8 decreased cell viability and induced apoptosis, along with the induction of C/EBP homologous protein (CHOP); its combination with bortezomib exhibited more anti-myeloma effects than KIRA8 alone. Nilotinib exerted a similar effect compared with KIRA8. RNA-sequencing identified Polo-like kinase 2 (PLK2) as a KIRA8-suppressed gene. Specifically, the IRE1α overexpression induced PLK2 expression, which was decreased by KIRA8. KIRA8 and PLK2 inhibition exerted anti-myeloma effects with apoptosis induction and the regulation of cell proliferation. Finally, PLK2 was pathologically confirmed to be highly expressed in patients with MM. CONCLUSION: Dominant activation of adaptive IRE1α was established in patients with MM. Both KIRA8 and nilotinib exhibited anti-myeloma effects, which were enhanced by bortezomib. Adaptive IRE1α signaling and PLK2 could be potential therapeutic targets and biomarkers in MM.

Expression of unfolded protein response markers in the pheochromocytoma with Waardenburg syndrome: a case report.

BACKGROUND: It is clinically emergent to further understand the pathological mechanism to advance therapeutic strategy for endocrine tumors. A high amount of secretory protein with tumorigenic triggers are thought to induce unfolded protein response in endoplasmic reticulum in endocrine tumors, but its evidence is limited. CASE PRESENTATION: A 40-year-old woman had an approximately 10-year history of intermittent headaches. After the incidental detection of a mass in her right adrenal gland by CT scan, she was admitted to our hospital. She had been diagnosed as type 1 Waardenburg syndrome with the symptoms of dystopia canthorum, blue iris, and left sensorineural hearing loss. Urinary catecholamine levels were markedly elevated. 123I-MIBG scintigraphy showed uptake in the mass in her adrenal gland. After the adrenalectomy, her headaches disappeared and urinary catecholamine levels decreased to normal range within 2 weeks. Genome sequencing revealed germline mutation of c.A175T (p.Ile59Phe) in transcription factor PAX3 gene and somatic novel mutation of c.1893_1898del (p. Asp631_Leu633delinsGlu) in proto-oncogene RET in her pheochromocytoma. RNA expression levels of RET were increased 139 times in her pheochromocytoma compared with her normal adrenal gland. Those of unfolded protein response markers, Bip/GRP78, CHOP, ATF4, and ATF6, were also increased in the pheochromocytoma. CONCLUSION: We report a rare case of pheochromocytoma with type 1 Waardenburg syndrome. This is the first case to show the activation of unfolded protein response in the pheochromocytoma with the novel somatic mutation in RET gene. Our findings may support that unfolded protein response is activated in endocrine tumors, which potentially could be a candidate of therapeutic target.

False-positive staining of thyroglobulin distinguished from mixed medullary and follicular thyroid carcinoma by duplex in situ hybridization.

Medullary thyroid carcinoma (MTC) may mimic mixed medullary and follicular thyroid carcinoma (MMFTC). MTC originates from para-follicular cells, while MMFTC is an uncommon tumor characterized by coexistence of follicular and para-follicular cell-derived tumor populations. A 35-year-old woman was diagnosed with MTC but showed a hot nodule in thyroid scintigraphy. The tumor included diffusely-spread follicular lesions within it, which were immunostained with thyroglobulin and calcitonin. Immunofluorescence showed the presence of several tumor cells that were double-stained with thyroglobulin and calcitonin. To clarify whether or not the tumor was MMFTC, we used duplex in situ hybridization (ISH). Thyroglobulin and calcitonin-related polypeptide alpha mRNA were not expressed together in a single cell, so we suspected false-positive staining of tumor cells with thyroglobulin. To make comparisons with other follicular lesions in MTC, we searched our hospital database. Five cases within a ten-year period had been pathologically diagnosed as MTC. All had follicular lesions in the tumor, but unlike the other case, they were peripherally localized. Dual differentiation into follicular or para-follicular tumor cells was not indicated by either immunofluorescence or duplex ISH. Compared with the case suspected to be MMFTC, there was only mild invasion of tumor cells into the follicular epithelium. The extent of follicular lesions and invasiveness of tumor cells may be associated with pseudo-staining of thyroglobulin in MTC. Duplex ISH can distinguish MTC that are stained with thyroglobulin from MMFTC.