Embryological Basis Research Articles

Parathyroid Adenoma of the Piriform Sinus: Case Series, Embryologic Basis, and Review of the Literature

ABSTRACT Objective: Parathyroidectomy is a procedure best performed by experienced parathyroid surgeons. Ectopic parathyroid adenoma is a well-described entity that can lead to a failed parathyroidectomy. Parathyroid adenoma of the piriform sinus is especially rare. Methods: Herein, we present a case series of 2 patients with ectopic parathyroid adenoma of the piriform sinus who underwent transoral resection of the lesion. Results: Both patients were successfully treated in our case series, and enjoyed an appropriate return to normal calcium and parathyroid levels. We further highlight the embryologic basis for this entity and present the available literature regarding surgical extirpation of parathyroid adenoma of the piriform sinus. Conclusion: Herein, we describe a transoral approach to piriform sinus adenomas in 2 patients. Both procedures were successful and without sequelae. We further provide a brief discussion of the management of other known cases of piriform sinus adenoma as well as their embryo...

A Study of Embryological Basis of Variations of Renal Vessels

A Study of Embryological Basis of Variations of Renal Vessels

Bilateral Variations in Median Nerve Formation with Embryological Basis and Clinical Correlation

Bilateral Variations in Median Nerve Formation with Embryological Basis and Clinical Correlation

Congenital anomalies of the IVC-embryological perspective and clinical relevance.

With the increased use of cross-sectional imaging, systemic venous anomalies are more frequently being recognized in asymptomatic patients. Accurate characterization of systemic venous anomalies plays a major role in the appropriate selection of a surgical approach or interventional procedure. In this article, we review common and uncommon inferior vena cava (IVC) anomalies. We describe the embryological basis and clinical implications of these anomalies, particularly from an interventional radiology perspective. We also discuss the complications and treatments of these anomalies.

Variations in branching pattern of arch of aorta in Gujarat region

Abstract Background and aim: Study of variation in branching pattern of arch of aorta is important for cardio­ vascular surgeons to avoid injury during procedures like angiography and stenting of aorta. These variations are frequently encountered during surgical procedures, as a developmental alteration in branchial arch during embryonic period. The aim of present study is to describe variation in branching pattern of arch of aorta belonging to Gujarati population and these results will be of significance for anatomists for relating it with embryological basis, cardiovascular surgeons and radiologists. Materials and metbods: Forty embalmed cadavers were observed for study of branching pattern of arch of aorta during period of four year in Department of Anatomy in Smt N.H.L.Municipal Medical College, Ahmedabad. Results: In the present study, normal branching pattern of the arch of aorta was found in 92.5% cases. In 2.5% cases only two vessels originated from the arch of aorta, one of them was common trunk for brachiocephalic trunk and left common carotid artery and the second trunk was left subclavian artery. In 5% of cases four vessels arose from arch of aorta, the left vertebral artery arose directly from aorta with normal branching pattern. Conclusion: Vascular invasive procedures are increasing since last decade. So knowledge of variation in branches of arch of aorta is essential for cardiologist, cardiovascnlar surgeon as well as for radiologist.

Poland Syndrome

SESSION TITLE: Fellow Case Report Poster - Genetic and Developmental Disorders SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Poland syndrome is a rare congenital disorder, characterized by unilateral absence or hypoplasia of chest wall muscles, costal cartilages and breast tissue and in some cases ipsilateral limb shortening and symbrachydactyly. CASE PRESENTATION: We report the case of a 58 year old Caucasian man who was incidentally detected to have a chest wall deformity on routine chest radiograph and subsequently noted to have hypoplasia of chest wall muscles on Computed Tomography. On physical examination he had flattening and excavation of his left chest wall, marked by the absence of nipple or breast tissue [Figure 1]. His left arm was shorter but had normal digits. Right chest wall and arms were normal. Muscle power was 5/5 on both sides and he had no neurological deficits. He had no family history of congenital disorders. He is a construction worker and has no functional limitation. His chest radiography revealed hyperlucency of left chest wall as compared to the right. Computed tomography images revealed hypoplasia of the pectoralis major and minor muscles and rib hypoplasia on the left side [Figure 2]. Echocardiogram was normal. DISCUSSION: Poland syndrome was first described by Sir Richard Poland in 1841 and typically consists of unilateral absence or hypoplasia of the chest wall muscles, costal cartilages, breast tissue, nipple and symbrachydactyly. Incidence is estimated at 1 in 100,000 live births with a male preponderance. The pathogenesis is unclear but considered to be a developmental vascular defect, occurring at about the 6th week of gestation, due to diminished blood supply to the developing arm and muscle buds. Various reconstructive surgeries can be performed for cosmetic and functional reasons. Our patient did not have any functional limitation and did not require any intervention. CONCLUSIONS: Poland syndrome is a rare congential anomaly involving unilateral thoracic musculoskeletal structures that usually do not result in any functional impairment. However it has rarely been associated with diaphragmatic hernia, dextrocardia and renal anomalies, which need to be screened for. Reference #1: Cingel V, Bohac M, Mestanova V, Zabojnikova L, Varga I. Poland syndrome: from embryological basis to plastic surgery. Surg Radiol Anat. 2013;35(8):639-46. Reference #2: Sharma CM, Kumar S, Meghwani MK, Agrawal RP. Poland syndrome. Indian J Hum Genet. 2014;20(1):82-4. Reference #3: Panda SS, Bajpai M, Singh A, Jana M. Poland syndrome involving the left hemithorax with dextrocardia and herniation of the spleen. BMJ Case Rep. 2014;2014. DISCLOSURE: The following authors have nothing to disclose: Deepak Chandra, Amol Patil, Krishna Siva Sai Kakkera, Deepa Jayakrishnan No Product/Research Disclosure Information

Cadaveric Study of Variation in the Formation of Trunks of Brachial Plexus, Embryological Basis and its clinical Significance

Cadaveric Study of Variation in the Formation of Trunks of Brachial Plexus, Embryological Basis and its clinical Significance

Eustachian tube communicating with sphenoid sinus: report of a novel anatomical variant.

Reports of congenital anomalies of the Eustachian Tube (ET) are scarce, and often associated with chromosomal abnormalities. We report a unique case of a completely bony left Eustachian tube which communicated with the sphenoid sinus. This report details these findings and discusses the potential embryological basis and implications of such an unusual anatomy, in the context of a comprehensive literature review.

Study of variations in the origin of obturator artery

Introduction: Obturator artery is the branch of anterior division of internal iliac artery. Variations in its origin are quite common and are very important from surgical point of view. Methods: To study the variations in the origin of the obturator artery 35 dissected vessels were studied. Results: Commonest variation of its origin from the posterior division of internal iliac artery was found in five cases. Other variations like its origin from internal pudendal artery or from inferior gluteal artery were also found, which are also discussed along with its embryological basis and clinical significance. Conclusions: Knowledge of anomalous origin of obturator artery from posterior division is helpful to vascular surgeons while planning endovascular treatment.

Variations in blood supply to kidney, suprarenal gland and gonad – its clinical importance and embryological basis

Variations in blood supply to kidney, suprarenal gland and gonad – its clinical importance and embryological basis

A Possible Mechanism of Zika Virus Associated Microcephaly: Imperative Role of Retinoic Acid Response Element (RARE) Consensus Sequence Repeats in the Viral Genome.

Owing to the reports of microcephaly as a consistent outcome in the fetuses of pregnant women infected with ZIKV in Brazil, Zika virus (ZIKV)—microcephaly etiomechanistic relationship has recently been implicated. Researchers, however, are still struggling to establish an embryological basis for this interesting causal handcuff. The present study reveals robust evidence in favor of a plausible ZIKV-microcephaly cause-effect liaison. The rationale is based on: (1) sequence homology between ZIKV genome and the response element of an early neural tube developmental marker “retinoic acid” in human DNA and (2) comprehensive similarities between the details of brain defects in ZIKV-microcephaly and retinoic acid embryopathy. Retinoic acid is considered as the earliest factor for regulating anteroposterior axis of neural tube and positioning of structures in developing brain through retinoic acid response elements (RARE) consensus sequence (5′–AGGTCA–3′) in promoter regions of retinoic acid-dependent genes. We screened genomic sequences of already reported virulent ZIKV strains (including those linked to microcephaly) and other viruses available in National Institute of Health genetic sequence database (GenBank) for the RARE consensus repeats and obtained results strongly bolstering our hypothesis that ZIKV strains associated with microcephaly may act through precipitation of dysregulation in retinoic acid-dependent genes by introducing extra stretches of RARE consensus sequence repeats in the genome of developing brain cells. Additional support to our hypothesis comes from our findings that screening of other viruses for RARE consensus sequence repeats is positive only for those known to display neurotropism and cause fetal brain defects (for which maternal-fetal transmission during developing stage may be required). The numbers of RARE sequence repeats appeared to match with the virulence of screened positive viruses. Although, bioinformatic evidence and embryological features are in favor of our hypothesis, additional studies including animal models are warranted to validate our proposition. Such studies are likely to unfold ZIKV-microcephaly association and may help in devising methods to combat it.

Early development of the malleus and incus in humans.

It is widely accepted by developmental biologists that the malleus and incus of the mammalian middle ear are first pharyngeal arch derivatives, a contention based originally on classical embryology that has now been backed up by molecular evidence from rodent models. However, it has been claimed in several studies of human ossicular development that the manubrium of the malleus and long process of the incus are actually derived from the second arch. This 'dual-arch' interpretation is commonly presented in otolaryngology textbooks, and it has been used by clinicians to explain the aetiology of certain congenital abnormalities of the human middle ear. In order to re-examine the origins of the human malleus and incus, we made three-dimensional reconstructions of the pharyngeal region of human embryos from 7 to 28 mm crown-rump length, based on serial histological sections from the Boyd Collection. We considered the positions of the developing ossicles relative to the pharyngeal pouches and clefts, and the facial and chorda tympani nerves. Confirming observations from previous studies, the primary union between first pharyngeal pouch and first cleft found in our youngest specimens was later lost, the external meatus developing rostroventral to this position. The mesenchyme of the first and second arches in these early embryos seemed to be continuous, but the boundaries of the developing ossicles proved to be very hard to determine at this stage. When first distinguishable, the indications were that both the manubrium of the malleus and the long process of the incus were emerging within the first pharyngeal arch. We therefore conclude that the histological evidence, on balance, favours the 'classical' notion that the human malleus and incus are first-arch structures. The embryological basis of congenital ossicular abnormalities should be reconsidered in this light.

Síndrome de deleción 22q11: bases embriológicas y algoritmo diagnóstico

The 22q11 deletion syndrome is characterized by a variable group of phenotypic features secondary to the loss of genetic material located on the band 22q11.2. Its spectrum covers multiple syndromes, previously considered independent but nowadays related to the same etiology with overlapping anomalies, including DiGeorge and velocardiofacial syndromes. It presents alterations in the immune and cardiac systems, neurodevelopment and palatal defects amongst the most common problems.This article is a review of the embryologic basis for the congenital heart defects, epidemiology, genetics, pathophysiology and clinical aspects of this disease. This is a rare disease but is a potentially underdiagnosed cause of morbidity and mortality in Colombia, for which a strategy for its active search is also proposed and diagnostic aspects are discussed.

Epilepsy in Neurological Phenotypes of Epidermal Nevus Syndrome

Epidermal nevus syndrome (ENS) encompasses a group of congenital genetic disorders characterized by the association of an epidermal nevus with systemic anomalies including the brain. The most frequent subtype with neurological features is <i>linear sebaceous nevus syndrome</i> (LSNS), followed by keratinocytic nevus syndrome (ENS). Both are caused by postzygotic <i>RAS</i> mutations. All forms of ENS are mosaic disorders that share a common embryological basis and pathogenesis as <i>neurocristopathies</i>. The lines of Blaschko indicate the cutaneous migratory pathways of neural crest. Neural crest defects explain the development of nevi and associated multisystemic anomalies: brain, ocular, osseous, muscular, orodental, cardiovascular, endocrine, renal/urinary, and adipose tissue. Epilepsy and cognitive and motor deficits are caused mainly by hemimegalencephaly (HME), a closely related mosaic anomaly caused by somatic mutations in PI3K–AKT3–mTOR pathway that determines overgrowth. The usual onset of epilepsy is in the neonatal period or early infancy, often as infantile spasms. The pioneer description of nevus sebaceous in 1895 by Jadassohn is the basis for delineating the LSNS. The eponym “Schimmelpenning syndrome” as a substitute for that long-established term makes no sense in the context of the large number of authors who contributed to defining this syndrome. A review of 111 cases of LSNS and other subtypes enabled a classification of neurological phenotypes; epilepsy occurred in 77% and HME in 38%. Three distinctive additional syndromes also are within the spectrum of ENS: CLOVES, SCALP, and Heide's syndrome. The impact of epilepsy in patients affected by ENS is related to time of onset and extent of brain anomalies. Timing of the mutation determines the phenotype and severity of the systemic lesions.

Double Superior Vena Cava: A Case Report

During routine dissection, a double superior vena cava, which is commonly known as persistent left superior vena cava (PLSVC) was observed in a 75‐ year‐old female cadaver. PLSVC drained into the right atrium through the coronary sinus. Coronary sinus was abnormally dilated to accommodate the large volume of venous blood reaching it through the PLSVC. Three sets of veins; common cardinal, anterior cardinal and posterior cardinal veins are involved in the normal development of the vena cavae. Embryological basis of PLSVC and its clinical significance in heart diseases will be discussed.

Accessory right crus of the diaphragm – a case report

The diaphragm is a dome-shaped sheet of muscle that separates the thoracic and abdominal cavities. Diaphragm is the principle muscle of inspiration and is present only in mammals. The muscle fibres, forming the periphery of the partition, arise from the circumference of the thoracic outlet and are inserted into a central tendon. During routine gross anatomy dissection of the abdomen, for the purpose of teaching medical students, in a middle-aged male cadaver, we observed an unusual morphology of the right crus of diaphragm. There were two crura on the right side of diaphragm and the left side was normal. Therefore, an attempt has been made to highlight its embryological basis and clinical implications.

A Study on Variations of Levator Palpebrae Superioris Muscle with Its Embryological Basis and Clinical Significance

A Study on Variations of Levator Palpebrae Superioris Muscle with Its Embryological Basis and Clinical Significance

Common peroneal nerve entrapment with the communication between inferior gluteal nerve and common peroneal nerve

Sciatic nerve divides into tibial nerve and common peroneal nerve at the level of superior angle of popliteal fossa and variations in its branching pattern are common. The most common nerve entrapment syndrome in the lower limbs is common peroneal nerve entrapment at fibular head. Invariably it can also be trapped in gluteal region due to split piriformis muscle which compresses sciatic nerve as whole or its division such as common peroneal nerve. In this case report, we describe a case of high division of sciatic nerve along with duplicated piriformis associated with a communicating branch between inferior gluteal nerve and common peroneal nerve. Such an anatomical variation of common peroneal nerve with the communicating nerve is discussed with its embryological basis.

Multi-modality imaging review of congenital abnormalities of kidney and upper urinary tract.

Congenital abnormalities of the kidney and urinary tract (CAKUT) include a wide range of abnormalities ranging from asymptomatic ectopic kidneys to life threatening renal agenesis (bilateral). Many of them are detected in the antenatal or immediate postnatal with a significant proportion identified in the adult population with varying degree of severity. CAKUT can be classified on embryological basis in to abnormalities in the renal parenchymal development, aberrant embryonic migration and abnormalities of the collecting system. Renal parenchymal abnormalities include multi cystic dysplastic kidneys, renal hypoplasia, number (agenesis or supernumerary), shape and cystic renal diseases. Aberrant embryonic migration encompasses abnormal location and fusion anomalies. Collecting system abnormalities include duplex kidneys and Pelvi ureteric junction obstruction. Ultrasonography (US) is typically the first imaging performed as it is easily available, non-invasive and radiation free used both antenatally and postnatally. Computed tomography (CT) and magnetic resonance imaging (MRI) are useful to confirm the ultrasound detected abnormality, detection of complex malformations, demonstration of collecting system and vascular anatomy and more importantly for early detection of complications like renal calculi, infection and malignancies. As CAKUT are one of the leading causes of end stage renal disease, it is important for the radiologists to be familiar with the varying imaging appearances of CAKUT on US, CT and MRI, thereby helping in prompt diagnosis and optimal management.

Study of Variations in the Origin of Obturator Artery

Introduction: Obturator artery is the branch of anterior division of internal iliac artery. Variations in its origin are quite common and are very important from surgical point of view. Methods: To study the variations in the origin of the obturator artery 35 dissected vessels were studied. Results: Commonest variation of its origin from the posterior division of internal iliac artery was found in five cases. Other variations like its origin from internal pudendal artery or from inferior gluteal artery were also found, which are also discussed along with its embryological basis and clinical significance. Conclusions: Knowledge of anomalous origin of obturator artery from posterior division is helpful to vascular surgeons while planning endovascular treatment.