CRAC channels and disease - From human CRAC channelopathies and animal models to novel drugs

Ca²⁺ release-activated Ca²⁺ (CRAC) channels are intimately linked with health and disease. The gene encoding the CRAC channel, ORAI1, was discovered in part by genetic analysis of patients with abolished CRAC channel function. And patients with autosomal recessive loss-of-function (LOF) mutations in ORAI1 and its activator stromal interaction molecule 1 (STIM1) that abolish CRAC channel function and store-operated Ca²⁺ entry (SOCE) define essential functions of CRAC channels in health and disease. Conversely, gain-of-function (GOF) mutations in ORAI1 and STIM1 are associated with tubular aggregate myopathy (TAM) and Stormorken syndrome due to constitutive CRAC channel activation. In addition, genetically engineered animal models of ORAI and STIM function have provided important insights into the physiological and pathophysiological roles of CRAC channels in cell types and organs beyond those affected in human patients. The picture emerging from this body of work shows CRAC channels as important regulators of cell function in many tissues, and as potential drug targets for the treatment of autoimmune and inflammatory disorders.

Infarcted accessory spleen masquerading as a mesenteric cyst

An accessory spleen is a rare entity which is usually asymptomatic. When symptomatic, it presents as an acute abdomen, with either torsion, rupture or haemorrhage. We present the case of a 20-year-old man who presented with chronic lower abdominal pain since 3 months and a lump in the left lower quadrant. On clinical examination and investigations, the lump was diagnosed as a mesenteric cyst, and an uncomplicated laparoscopic excision was performed. The postoperative histopathological examination reported it as an infarcted accessory spleen.

An Intrapancreatic Accessory Spleen That Was Difficult to Diagnose Due to Temporal Changes after Splenectomy

Accessory spleen (AS) is common anomaly, and 20% of AS cases occur in the pancreatic tail. An intrapancreatic AS can be difficult to distinguish from pancreatic neoplasms. In most cases, an AS is described as a hypervascular and solitary tumor, but an AS sometimes takes other forms. We herein report a rare case of an intrapancreatic AS with temporal changes in its appearance after splenectomy, which mimicked aspects of pancreatic cancer. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and ^99mTc sulfur colloid scintigraphy were useful for the diagnosis.

Intrapancreatic accessory spleen. Report of four cases diagnosed by ultrasound-guided fine-needle aspiration biopsy

Intrapancreatic accessory spleen (IPAS) is a congenital anomaly usually misdiagnosed as a pancreatic neoplasm. For five years and four months, we collected seven IPASs located in the tail of the pancreas in four patients diagnosed by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). All cases had associated cell block preparations. Each patient underwent endoscopic ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) studies. The patients ranged in age from 57 to 73 years (mean age 65.7 years old). All lesions were well-defined, 1-1.9 cm in size (mean 1.5 cm). To our knowledge, a case with four IPASs in the tail of the gland has not been previously reported. Cytological features of IPAS included a polymorphous population of hematopoietic cells admixed with occasional blood vessels. Cell blocks comprised spleen red pulp. CD8 immunostaining of cell blocks highlighted splenic endothelial cells and confirmed the diagnosis. IPAS presented as an asymptomatic lesion detected on imaging studies. It may mimic a pancreatic neoplasm, mainly a neuroendocrine tumor. The use of EUS-FNA is an essential tool in the diagnosis of the lesion. The endothelial cells of the splenic sinuses characterized by their positivity for CD8 are evident in the sections of the cell blocks. This staining is considered specific and can be used as a confirmatory marker. EUS-FNA biopsy provides a reliable diagnosis that prevents unnecessary surgery.

Ruptured Sinus of Valsalva Aneurysm Associated with Situs Ambiguus, Isolated Levocardia, and Polysplenia

Aneurysm of the sinus of Valsalva, a rare cardiac condition, results from dilation of an aortic sinus. Sudden aneurysm rupture can trigger rapidly progressive heart failure. We discuss the case of a 57-year-old woman with situs ambiguus, isolated levocardia, and polysplenia who presented with acute-onset heart failure. Transesophageal echocardiograms revealed an aneurysm of the right coronary sinus of Valsalva that had ruptured into the right atrial cavity. The patient underwent successful surgical repair. To our knowledge, this is the first report of a sinus of Valsalva aneurysm in a patient with this combination of congenital abnormalities. We briefly review the association between congenital heart disease, situs ambiguus, and ciliary dysfunction.

Howell-Jolly bodies and liver-spleen scanning for assessment of splenic filtrative function yields discordant results in renal transplant recipients

Given discrepancies between methods for diagnosing hyposplenism, the purpose of this study was to evaluate the effect of the spleen size on the correlation between the methods, and to propose a model for improving the interpretation. Patients with renal allografts were included, in whom the spleen was assessed using Doppler ultrasound, scintiscan, and the presence of Howell-Jolly bodies (HJBs) in peripheral smears. In 35 subjects, scintiscan and HJBs were normal (Group 0); 20 had an abnormal result in both methods (Group 1); 34 had discordant results with HJBs present (Group 2); and 14 had discordant results with decreased spleen uptake (Group 3). There was no association between HJBs and scintiscan. The patients of Groups 1 and 2 had smaller spleens. The patients with smaller spleen had more hematological evidence of hyposplenism and exhibit smaller discrepancies between the methods than patients with larger spleen. The spleen can tip the balance from a normal to impaired function provided that the spleen size is below the critical mass required to maintain splenic function. A mild impairment of phagocytic function and slight dyserythropoiesis along with a small spleen would result in decreased take up of radiocolloid or the appearance of HJBs in blood smears.

Case report of intestinal non-rotation, heterotaxy, and polysplenia in a patient with pancreatic cancer

RATIONALE

Heterotaxy with polysplenia is an extremely rare congenital condition resulting from abnormal arrangement of organs in the abdominal and thoracic cavities during embryologic development. When a malignancy such as pancreatic cancer develops under these conditions, surgical resection becomes particularly complex. This case report demonstrates successful pancreatic cancer resection despite the patient's complicated anatomy.

PATIENT CONCERNS

An 82-year-old female presented to our institution with complaints of mild right upper quadrant pain radiating to the mid-epigastric region.

DIAGNOSES

Physical examination revealed jaundice with scleral icterus consistent with obstructive jaundice. Radiographic imaging revealed hepatic duct dilation with several anatomic anomalies including small bowel location in the right upper abdomen, cecum, and appendix in the left lower quadrant, reversed superior mesenteric artery and superior mesenteric vein positions, and right-sided duodenal-jejunal flexture as well as an entirely right-sided pancreas, and left lower pelvis with ≥6 separate splenules. These findings resulted in a diagnosis of heterotaxy syndrome with polysplenia.

INTERVENTIONS

Careful preoperative planning and total pancreatectomy was performed without complication.

OUTCOMES

The patient recovered well. Pathologic examination of the pancreatic mass revealed moderately/poorly differentiated invasive pancreatic duct adenocarcinoma. The patient remains alive and well without signs of recurrent disease at the 2-year follow-up.

LESSONS

Given the wide range of anatomical variants observed in patients with heterotaxy syndrome, a thorough radiologic assessment is necessary before engaging in any surgical procedure. In our case, preoperative identification of the various anatomic anomalies, such as the short and vertically oriented pancreas, the porta hepatis position anterior to the duodenum, the nonrotation of the intestines and the anomalous origin of the right hepatic artery allowed us to perform a safe and uncomplicated total pancreatectomy.

Symptomatic pelvic accessory spleen in a female adolescent: Case report

Accessory spleens are congenital foci of healthy splenic tissue that are separate from the main body of the spleen. They occur in 10-30% of individuals; a wandering accessory spleen located in the pelvis is uncommon. Most patients are asymptomatic. We describe the case of a female adolescent presenting with acute abdominal pain who had a pelvic accessory spleen that mimicked an adnexal mass. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:600-602, 2017.

A spontaneous hematoma arising within an intrapancreatic accessory spleen: A case report and literature review

RATIONAL

Hematoma arising within an intrapancreatic accessory spleen (IPAS) is an extremely rare pathological entity.

PATIENT CONCERN

We present the case of a 39-year-old man with acute abdominal pain.

DIAGNOSES

The patient was initially diagnosed as pancreatic cystic neoplasm according to CT and MRI imaging.

INTERVENTIONS

Distal pancreatectomy was conducted because of the possibility of malignancy.

OUTCOMES

Surgical resection showed that the lesion was a hematoma in an IPAS.

LESSONS

Our case indicated that the differential diagnosis of hematoma in IPAS should be born in mind for cases with cystic neoplasm in tail of pancreas and an epidermoid cyst arising within an intrapancreatic accessory spleen (ECIAS).

Colonic obstruction caused by accessory spleen torsion: A rare case report and literature review

RATIONALE

Accessory spleen torsion is a rare cause of the acute abdomen. The complications of accessory spleen torsion, such as intestinal obstruction, are rarer. We herein report a case of colonic obstruction caused by accessory spleen torsion because of the unusual condition.

PATIENT CONCERNS

A 15-year-old patient presented with acute intestinal obstruction with signs of peritoneal irritation. Abdominal computed tomography (CT) and ultrasonography examinations revealed a soft tissue mass in the left midabdomen. Systemic inflammatory response syndrome (SIRS) was observed in this case.

DIAGNOSES

The diagnosis of peritonitis and colonic obstruction secondary to accessory spleen torsion was made. Pathologic examination showed infracted splenic tissue.

INTERVENTIONS

We performed emergency laparotomy and found that accessory spleen torsion pressured against splenic flexure and descending colon, and caused colon obstruction. The patient underwent accessory splenectomy and enteral decompression.

OUTCOMES

At 6 months follow-up, the patient recovered well with perfect digestion.

LESSONS

Accessory spleen torsion and its complications are extremely rare. This entity should be considered in differential diagnosis of acute abdomen. However, in case of acute abdomen with critical clinical situation, emergency surgical intervention is necessary for timely diagnosis and treatment.

Ultrasound of congenital and inherited disorders of the pediatric hepatobiliary system, pancreas and spleen

Ultrasound is often the initial imaging examination performed of the solid organs of the pediatric abdomen. The sonographic appearance of the hepatobiliary system, pancreas and spleen changes with growth and development. This article reviews the normal US appearance of these organs in children and illustrates, through case examples, congenital and inherited conditions that affect them.

Bilobate wandering spleen with doble torsion of the vascular pedicle. A case report

INTRODUCTION

Wandering spleen is a rare clinical condition which is often an incidental finding. It is characterized by excessive mobility and displacement of the spleen within the abdomen; although the spleen is usually of normal size it has an elongated vascular pedicle .

CASE STUDY

We present the case of an adult woman who complaining of abdominal pain who was brought to our institution for emergency treatment. She later developed an acute abdomen due to infarction of a wandering spleen caused by double torsion of the vascular pedicle. Emergency splenectomy was performed.

RESULTS

Surgical treatment of a wandering spleen is generally conservative and consists in splenoplexy. In our case, complicated by ischemia leading to irreversible damage of the spleen, splenectomy was the solution.

DISCUSSION

The long vascular pedicle of a migrant spleen is at risk of torsion which can cause irreversible acute ischemia of the spleen. Therefore a timely diagnosis with the use of modern imaging techniques is of primary importance.

CONCLUSIONS

Early interpretation of the symptoms and computed tomography angiography can prevent the complications that result from torsion of the elongated pedicle.

KEY WORDS

Acute abdomen, Bilobate wandering spleen, Splenectomy.

Sonographic diagnosis of splenogonadal fusion in a 2-year-old boy

Splenogonadal fusion (SGF) is a rare congenital abnormality. It is typically identified during orchiectomy for a suspected testicular tumor or during orchiopexy. We describe the sonographic findings in a case of SGF that could help with correct diagnosis preoperatively. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:179-182, 2017.

Intrapancreatic accessory spleen: An eluding diagnosis

Intrapancreatic accessory spleen (IPAS) is a benign anomaly of splenic embryology and a rare cause of pancreatic pseudotumour. Here, we report a case of a 70-year-old Malay lady whose IPAS was discovered incidentally during her surveillance computed tomography for her underlying left lower lung fibrosis. Radiologically, the lesion mimicked a neuroendocrine pancreatic tumour and was only diagnosed pathologically as IPAS after surgery. In conclusion, recognising IPAS as a differential for enhancing pancreatic mass allows us to exhaust all non-invasive diagnostic means to diagnose this benign lesion. It will allow the patient to avoid unnecessary surgery and its accompanying complications.

Spleen Behind the Heart Complicates Lung-to-Head Ratio Measurement in Left-Sided Congenital Diaphragmatic Hernia

In fetuses with left-sided congenital diaphragmatic hernia, intrathoracic herniation of the spleen is a common occurrence. The herniated spleen can reside posterior to the left atrium of the heart in the right hemithorax and is increasingly differentiated from the lung with the use of newer sonographic equipment. Estimation of the neonatal prognosis relies on accurate measurement of fetal lung size, particularly with commonly used measurements such as the lung-to-head ratio. Here we describe how herniation of the spleen behind the heart can complicate measurement of the lung-to-head ratio on sonography and lead to overestimation, with implications for perinatal prognostication and management.

An unusual case of repeated splenectomy: traumatic rupture of an accessory spleen in a previously splenectomized patient

The traumatic rupture of an accessory spleen is a very rare condition and only few cases have been reported in the literature. We describe the case of a 51-year-old man undergone splenectomy for trauma several years before, who developed hemoperitoneum due to a laceration of a voluminous accessory spleen, following an accidental two-meter fall. As a conservative management of the injury was not possible, an accessory splenectomy was then required. Thus, a briefly review of the literature about this uncommon topic was perfomed.

KEY WORDS

Accessory spleen, Laparotomy, Trauma.

Accessory spleen hypertrophy mimicking colon cancer metastasis

Accessory spleen is a congenital form of an ectopic splenic tissue. In this report, we present a case of a patient who was followed with the diagnosis of rectal and sigmoid colon cancer and an accessory spleen hypertrophy, which was thought to be colon cancer metastasis in the left hypochondriac region. After colectomy and splenectomy, accessory spleen that mimics cancer metastasis was diffrentially diagnosed using scintigraphy.

Spatial anatomy of the round ligament, gallbladder, and intrahepatic vessels in patients with right-sided round ligament of the liver

PURPOSE

To analyze the vascular structure of the liver in patients with a right-sided round ligament.

METHODS

We reviewed 16 patients with a right-sided round ligament and 3 polysplenia and situs inversus patients with a left-sided round ligament who underwent multidetector row CT with contrast media. The patient population consisted of 13 men and 6 women (mean 62 years). We analyzed the axial and volume-rendered images for the location of the round ligament, gallbladder, portal veins, hepatic veins, and hepatic artery. The following imaging findings for the patients with polysplenia and situs inversus were horizontally reversed.

RESULTS

The prevalence of a right-sided round ligament with and without polysplenia was 75 and 0.11 %, respectively. The gallbladder was located to the right, below, and left of the round ligament in 27.7, 38.8 and 33.3 %, respectively. Independent branching of the right posterior portal vein was noted in 57.8 %. PV4 was difficult to identify in 36.8 %. The middle hepatic vein was located to the left of the round ligament. Two branching patterns for the lateral and medial branches of the right anterior hepatic artery were noted: the common (44.4 %) and separated types (55.5 %). Both of the right anterior hepatic artery and portal vein ramified into two segments; the lateral segment with many branches and the medial segment with a few branches.

CONCLUSIONS

The right-sided round ligament divided the right anterior section into the lateral and medial segments based on the portal vein and hepatic artery anatomy.

Extracardiac anomalies in prenatally diagnosed heterotaxy syndrome

OBJECTIVE

To assess the incidence and impact of extracardiac anomalies on the prognosis of fetuses with heterotaxy syndrome.

METHODS

All fetuses diagnosed with heterotaxy syndrome by three experienced examiners over a period of 14 years (1999-2013) were reviewed retrospectively.

RESULTS

In total, 165 fetuses with heterotaxy syndrome were diagnosed in the study period. One hundred and fifty (90.9%) had cardiac defects; extracardiac anomalies that did not involve the spleen were present in 26/165 (15.8%) cases. Of the total study cohort, termination of pregnancy was performed in 49 (29.7%) cases, intrauterine death occurred in 11 (6.7%), postnatal death occurred in 38 (23.0%) and 67 (40.6%) were alive at the latest follow-up, resulting in a total perinatal and pediatric mortality of 59.4%. Among the 105 liveborn neonates, 15 (14.3%) had extracardiac anomalies with significant impact on the postnatal course: one neonate died following repair of an encephalocele, six had successful treatment for various types of intestinal malrotation and/or atresia and one underwent hiatal hernia repair; the remaining seven had biliary atresia, of which five died and the two survivors are awaiting liver transplantation. The status of the spleen was assessed in 93/105 liveborn children and was found to be abnormal in 84/93 (90.3%). There were three cases of lethal sepsis, all associated with asplenia. Of the 38 postnatal deaths, 29 (76.3%) had a cardiac cause, seven (18.4%) had an extracardiac cause and in two (5.2%) the reason was uncertain.

CONCLUSIONS

Although the leading causes of death in fetuses and children with heterotaxy syndrome are cardiac, a small subset of fetuses have extracardiac anomalies with significant impact on outcome. These anomalies often escape prenatal detection, and therefore neonates at risk should be monitored for bowel obstruction, biliary atresia and immune dysfunction in order to allow timely intervention through a multidisciplinary approach. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Osteocraniosplenic Syndrome-Hypomineralized Skull with Gracile Long Bones and Splenic Hypoplasia: A Case Report and Literature Review

Osteocraniosplenic syndrome-hypomineralized skull with gracile long bones and splenic hypoplasia: a case report and literature review: We report herein an intrauterine growth-restricted preterm nwonate with a lethal bone dysplasia characterized by severe hypomineralization of the skull, absent medullary lucency flared metaphyses fishbone-like diaphysis and overtubulated long vones. Dysmorphic features included flat facies, bulging forehead, vevus flammeus, depressed nasas bridge, short philtrum, inverted U-shape mouth, mild micrometic dwarfism, and brachydactyly. The infant's lungs and spleen were hypoplastic. The findings are compatible with the 19 previously reported cases that used different terminology: osteocraniostenosis, gracile bone disorders and osteocraniosplenic syndrome. We present the clinical, pathological and cytogenetic findings of this rare disorder.

Postsplenectomy recurrence of idiopathic thrombocitopenic purpura: role of laparoscopic splenectomy in the treatment of accessory spleen

AIM

Idiopatic thrombocytopenic purpura (ITP) is the most common indication for splenectomy. The failure rate of surgery is about 8% and the failure rate after splenectomy is approximately 28% for all patients. When the presence of an accessory spleen is diagnosed, splenectomy is recommended. Laparoscopic approach is considered the first choice.

PATIENTS AND METHODS

At our Department, between July and November 2011 two patients underwent laparoscopic accessory splenectomy for recurrence of ITP. Both patients had a previously laparoscopic splenectomy. Preoperative Magnetic Resonance (MR) was performed in both the cases revealing the presence of an accessory spleen.

RESULTS

The operative time was 105 and 100 minutes respectively. No perioperative complications occured. Hospital stay was four days in both cases. The first patient had a disease free period of two months; the second one of one month. Both patients restarted immunosuppressive therapy.

CONCLUSIONS

The relapse of thrombocytopenia post-splenectomy can be associated with the presence of an accessory spleen. The laparoscopic accessory splenectomy should be considered the first choice approach. Surgical accessory splenectomy allows a transitory remission of the disease.

York platelet syndrome is a CRAC channelopathy due to gain-of-function mutations in STIM1

Store-operated Ca(2+) entry is the major route of replenishment of intracellular Ca(2+) in animal cells in response to the depletion of Ca(2+) stores in the endoplasmic reticulum. It is primarily mediated by the Ca(2+)-selective release-activated Ca(2+) (CRAC) channel, which consists of the pore-forming subunits ORAI1-3 and the Ca(2+) sensors, STIM1 and STIM2. Recessive loss-of-function mutations in STIM1 or ORAI1 result in immune deficiency and nonprogressive myopathy. Heterozygous gain-of-function mutations in STIM1 cause non-syndromic myopathies as well as syndromic forms of miosis and myopathy with tubular aggregates and Stormorken syndrome; some of these syndromic forms are associated with thrombocytopenia. Increased concentration of Ca(2+) as a result of store-operated Ca(2+) entry is essential for platelet activation. The York Platelet syndrome (YPS) is characterized by thrombocytopenia, striking ultrastructural platelet abnormalities including giant electron-opaque organelles and massive, multilayered target bodies and deficiency of platelet Ca(2+) storage in delta granules. We present clinical and molecular findings in 7 YPS patients from 4 families, demonstrating that YPS patients have a chronic myopathy associated with rimmed vacuoles and heterozygous gain-of-function STIM1 mutations. These findings expand the phenotypic spectrum of STIM1-related human disorders and define the molecular basis of YPS.

[Children with asplenia or hyposplenia: Preventing overwhelming post splenectomy infection]

The spleen's ability to prevent overwhelming post-splenectomy infection (OPSI) is mainly given by its capacity to filter and phagocyte bacterial elements from the blood, remove foreign elements from it, and the early production of opsonins. The anatomic absence of the spleen is usually secondary to a surgical resection, but it could also be congenital. Streptococcus pneumoniae has been identified as the main agent of OPSI in asplenic patients with an extremely high global mortality associated. This article is an exhaustive review of the current evidence and recommendations available for prevention of invasive infections in asplenic patients.