Incidental Discovery of Klippel-Feil Syndrome: Beyond the Expected Clinical Triad.

Klippel-Feil syndrome (KFS) is a rare congenital disorder characterized by the fusion of cervical vertebrae, limiting neck mobility, and often presenting with clinical manifestations such as neck pain, stiffness, and neurological deficits. While the classical presentation of KFS includes a "clinical triad" comprising a shortened neck, a low posterior hairline, and limited cervical motion, not all patients exhibit all three features. This case report presents an 81-year-old male with the complete KFS triad and underscores the diagnostic challenges and management strategies associated with this condition. Despite the rarity of KFS, understanding it is crucial for clinicians due to its profound implications on patient management and quality of life. This case emphasizes the importance of clinical suspicion in Internal Medicine, showcasing how an isolated presentation may often be a manifestation of an underlying congenital condition.

Anesthetic Management of a Patient with Klippel-Feil Syndrome for Laparoscopic Pelvic Surgery: A Case Report.

Klippel-Feil Syndrome (KFS) continues to pose significant challenges for anesthesiologists. Beyond the expected complexities of managing difficult airways in these patients, they often present with systemic anomalies that can elevate the risk of morbidity during surgeries conducted under anesthesia. Furthermore, laparoscopic procedures bring about additional physiologic changes that must be taken into consideration when planning the anesthetic care for these individuals. This report details the anesthetic management of a 29-year-old female diagnosed with Klippel-Feil Syndrome (KFS) and concomitant Müllerian duct aplasia-Renal agenesis-Cervicothoracic Somite dysplasia (MURCS) as well as Chiari Type 1 Malformation, who underwent a successful pelvic laparoscopic surgery. The airway was secured through awake fiberoptic-guided intubation while general anesthesia was maintained with a combination of sevoflurane inhalation and remifentanil infusion. Intraoperatively, the team prioritized neuroprotection, lung-protective ventilation strategies, and renal preservation measures. The anesthetic management of patients with KFS necessitates a comprehensive assessment of their anomalies. Incorporating these considerations into the anesthetic management will help mitigate the procedure's adverse effects and lead to favorable patient outcomes.

The Assessment of Airway Compression Due to Cervical Fusion in Klippel-Feil Syndrome Patients: A Report of Two Cases.

In general anesthesia for Klippel-Feil syndrome (KFS) patients, there is a potential risk of difficult intubation. However, airway assessment to predict difficult intubation for KFS patients is not known. In Patient 1, cervical spine computed tomography (CT) revealed airway compression due to cervical fusion. For airway assessment, bronchofiberscopy, three-dimensional (3-D) CT, and virtual bronchoscopic image (VBI) construction were performed. Based on these images, fiberoptic nasotracheal awake intubation was performed. In Patient 2, magnetic resonance imaging and bronchofiberscopy showed no airway compression due to cervical fusion; therefore, tracheal intubation was performed using a video laryngoscope after anesthetic administration. Airway compression due to cervical fusion is considered one of the risk factors for difficult intubation in KFS patients.

Atlantooccipital assimilation associated with combined atlas arch defect: a radiological case report.

In this report, atlantooccipital assimilation (AS), anterior arch defect (AAD), and posterior arch defect (PAD) of the atlas, and several variations around the craniocervical junction were identified on computed tomography (CT) of a patient of unknown sex and age. Coronal and sagittal CT scans showed AS and bilateral fusion of the atlas and the base of occipital bone. Axial CT scan at the atlas revealed PAD type B on the left side and midline AAD. Morphometric measurements indicated a potential ventral spinal cord compression. In addition, mid-sagittal CT revealed the presence of fossa navicularis magna and incomplete formation of the transverse foramen on the right side. This study reports an extremely rare AS associated with AAD, PAD, and other variations of the clivus and the atlas. To our knowledge, no similar case has been reported in the literature.

Klippel-Feil Syndrome With Isolated Facial Dysmorphism: A Clinical Conundrum With Resemblance to Adenoid Facies.

Klippel-Feil syndrome (KFS) is a triad comprising cervical spine fusion, a low posterior hairline, and constrained neck movement. This triad is not universally present. The most frequent accompaniment is Sprengel's scapula deformity. According to the Feil classification, Class 1 (C1) is an immense fusion of many cervical vertebrae, Class 2 (C2) is a fusion of one or two vertebrae only, and Class 3 (C3) is coupled with thoracic and lumbar spinal vertebral fusion in addition to the fusion of the cervical vertebrae. Clarke's categorization of KFS includes other associated anomalies. The different classification systems for KFS have been made by the different specialists to whom patients may present, which include orthopedic surgeons, neurosurgeons, orthodontists, faciomaxillary surgeons, cardiologists, and pediatricians. This anomaly being rare and the lack of universally accepted classification may lead to confusion regarding the identification of the syndrome, especially the Clarke Type 3 with isolated facial dysmorphism may go undiagnosed. We report a case with KFS-Clarke Type 3 with isolated facial dysmorphism and Feil Type 2 with the fusion of C2-C3 cervical vertebrae, detected as an incidental radiologic finding, and initial impression of adenoid facies. Hence, this case also highlights the contrasting features between the facial dysmorphism of Clarke Type 3 KFS and adenoid facies.

Posterior Occipitocervical Fixation and Intrathecal Baclofen Therapy for the Treatment of Basilar Invagination with Klippel-Feil Syndrome: A Case Report.

Klippel-Feil syndrome (KFS) is characterized by the congenital fusion of the cervical vertebrae and is sometimes accompanied by anomalies in the craniocervical junction. In basilar invagination (BI), which is a dislocation of the dens in an upper direction, compression of the brainstem and cervical cord results in neurological defects and surgery is required. A 16-year-old boy diagnosed with KFS and severe BI presented with spastic tetraplegia, opisthotonus and dyspnea. CT scans showed basilar impression, occipitalization of C1 and fusion of C2/C3. MRI showed ventral compression of the medullocervical junction. Posterior occipitocervical reduction and fusion along with decompression were performed. Paralysis gradually improved postoperatively over 3 weeks. However, severe spasticity and opisthotonus persisted and intrathecal baclofen (ITB) therapy was initiated. Following this, opisthotonus disappeared and spasticity of the extremities improved. Rehabilitation therapy continued by controlling the dose of ITB. Five years after the surgery, self-propelled wheelchair driving was achieved and activities of daily life improved. The treatment strategy for patients with BI and congenital anomalies remains controversial. Posterior reduction and internal fixation using instrumentation were effective techniques in this case. Spasticity control achieved through a combination of surgery and ITB treatment enabled the amelioration of therapeutic efficacy of rehabilitation and the improvement of ADL.

Neglected Sprengel's deformity in an 80-year-old female cadaver: a case report.

BACKGROUND: Sprengel's deformity is a congenital abnormality of the shoulder girdle. Because scapular retraction, such as the Green procedure, is usually performed during childhood to improve esthetics and shoulder function, Sprengel's deformity is rarely found in older patients. CASE PRESENTATION: We presented a unique case of a Japanese female cadaver with Sprengel's deformity at the age of 80 years. Anatomical dissection and radiological imaging revealed musculoskeletal anomalies associated with Sprengel's deformity, including Klippel-Feil syndrome, presence of an omovertebral bone, and absence of the trapezius muscle. In addition, bilateral cervical ribs were in contact with the brachial plexus. These anomalies may lead to numbness, pain, and limited range of motion of the neck and upper girdle with aging. CONCLUSIONS: Because most adult patients with Sprengel's deformity experience neck pain and limited movement of the shoulder, the presented case is a rare case of neglected Sprengel's deformity in an 80-year-old cadaver.

Klippel-Feil syndrome: Should additional examination be conducted?

PURPOSE: Klippel-Feil syndrome (KF) is a rare disease defined as single or multi-level cervical vertebra fusion. KF could be accompanied by other spinal anomalies or isolated, and in which case necessity of whole spine screening is not clearly known. KF is investigated in terms of prevalence, gender distribution, fusion types, and frequency of accompanying anomalies according to types of KF. METHODS: Approval from our hospital's ethics committee was received for this single-center, retrospective study. Considering the exclusion criteria among the 40,901 cervical spine MRIs, 40,450 patients were included in the study. It was re-evaluated for KF, fusion level, classification, cervical scoliosis, and other musculoskeletal and spinal anomalies. RESULTS: 125 (0.309%) of 40,450 patients is diagnosed with KF, which is more common in women (P < 0.001). Single fused segment 106 (84.8%), multilevel fused segments 8 (6.4%), contiguous fused segments 11 (8.8%) are observed. Upper level KF is detected in 13 (10.4%) patients. The frequency of additional anomaly is significantly higher in upper level KF compared to other level fusions (P < 0.001, Chi-square t). The cervical scoliosis is diagnosed 34 (27%). In KF patients with scoliosis, the frequency of additional anomalies was significantly higher (P < 0.001, Chi-square t). CONCLUSION: Klippel-Feil prevalence is 0.309%, it is frequently observed in women, and at C2-C3 level. Additional anomalies are especially associated with 'contiguous fused segments' and 'upper level' types. Klippel-Feil with scoliosis is an indicator of increased risk for associated anomalies, and examination of the whole spine is recommended.

A Novel Technique for Basilar Invagination Treatment in a Patient with Klippel-Feil Syndrome: A Clinical Example and Brief Literature Review.

Objectives and Background: To present a novel technique of treatment for a patient with basilar invagination. Basilar invagination (BI) is a congenital condition that can compress the cervicomedullary junction, leading to neurological deficits. Severe cases require surgical intervention, but there is debate over the choice of approach. The anterior approach allows direct decompression but carries high complication rates, while the posterior approach provides indirect decompression and offers good stability with fewer complications. Materials and Methods: A 15-year-old boy with severe myelopathy presented to our hospital with neck pain, bilateral upper limb muscle weakness, and hand numbness persisting for 4 years. Additionally, he experienced increased numbness and gait disturbance three months before his visit. On examination, he exhibited hyperreflexia in both upper and lower limbs, muscle weakness in the bilateral upper limbs (MMT 4), bilateral hypoesthesia below the elbow and in both legs, mild urinary and bowel incontinence, and a spastic gait. Radiographs revealed severe basilar invagination (BI). Preoperative images showed severe BI and that the spinal cord was severely compressed with odontoid process. Results: The patient underwent posterior surgery with the C-arm free technique. All screws including occipital screws were inserted into the adequate position under navigation guidance. Reduction was achieved with skull rotation and distraction. A follow-up at one year showed the following results: Manual muscle testing results and sensory function tests showed almost full recovery, with bilateral arm recovery (MMT 5) and smooth walking. The cervical Japanese Orthopedic Association score of the patient improved from 9/17 to 16/17. Postoperative images showed excellent spinal cord decompression, and no major or severe complications had occurred. Conclusions: Basilar invagination alongside Klippel-Feil syndrome represents a relatively uncommon condition. Utilizing a posterior approach for treating reducible BI with a C-arm-free technique proved to be a safe method in addressing severe myelopathy. This novel navigation technique yields excellent outcomes for patients with BI.

Occipital dermal sinus associated with infectious teratoma in an adult patient affected by Klippel-Feil syndrome: Rare case report and literature review.

Background: The Klippel-Feil syndrome (KFS) is a rare congenital anomaly characterized by the fusion of cervical vertebrae, which may be associated with other malformations, such as dermoid tumors and teratoma. Some theories explain the embryology of these associations. Another condition that may be present is the dermal sinus (DS), communication between intracranial tumors and the subcutaneous tissue, and predisposing infections. This case report aims to describe an association between these three pathologies as well as correlate them from the literature. This report was based on medical records retrospectively reviewed associated with the systematic bibliographical consultation using indexed databases based on inclusion and exclusion methods. Case Description: An adult male patient, 24 years old, was admitted to our service, presenting fever and meningeal irritation as initial symptoms. In the patient's clinical history, he was diagnosed with an occipital DS in his childhood, which was previously instructed to be operated on by another neurosurgical team, but the patient chose not to perform the procedure. The magnetic resonance imaging investigation showed a DS associated with a cerebellar infected mass with 2 cm on its main diameter. The patient was treated with preoperative antibiotic therapy and underwent gross total surgical resection of the tumor as well as DS correction, confirmed in the histopathological examination as a teratoma. After surgery, further computed tomography scan analysis showed the presence of cervical vertebrae fusion, compatible with KFS diagnosis. Conclusion: The association between KFS, cerebellar teratoma, and DS has not yet been described in the literature, with only the association of the first two being extremely rare.

Genetic insights into the 'sandwich fusion' subtype of Klippel-Feil syndrome: novel FGFR2 mutations identified by 21 cases of whole-exome sequencing.

BACKGROUND: Klippel-Feil syndrome (KFS) is a rare congenital disorder characterized by the fusion of two or more cervical vertebrae during early prenatal development. This fusion results from a failure of segmentation during the first trimester. Although six genes have previously been associated with KFS, they account for only a small proportion of cases. Among the distinct subtypes of KFS, "sandwich fusion" involving concurrent fusion of C0-1 and C2-3 vertebrae is particularly noteworthy due to its heightened risk for atlantoaxial dislocation. In this study, we aimed to investigate novel candidate mutations in patients with "sandwich fusion." METHODS: We collected and analyzed clinical data from 21 patients diagnosed with "sandwich fusion." Whole-exome sequencing (WES) was performed, followed by rigorous bioinformatics analyses. Our focus was on the six known KFS-related genes (GDF3, GDF6, MEOX1, PAX1, RIPPLY2, and MYO18). Suspicious mutations were subsequently validated through in vitro experiments. RESULTS: Our investigation revealed two novel exonic mutations in the FGFR2 gene, which had not previously been associated with KFS. Notably, the c.1750A > G variant in Exon 13 of FGFR2 was situated within the tyrosine kinase domain of the protein, in close proximity to several established post-translational modification sites. In vitro experiments demonstrated that this certain mutation significantly impacted the function of FGFR2. Furthermore, we identified four heterozygous candidate variants in two genes (PAX1 and MYO18B) in two patients, with three of these variants predicted to have potential clinical significance directly linked to KFS. CONCLUSIONS: This study encompassed the largest cohort of patients with the unique "sandwich fusion" subtype of KFS and employed WES to explore candidate mutations associated with this condition. Our findings unveiled novel variants in PAX1, MYO18B, and FGFR2 as potential risk mutations specific to this subtype of KFS.

Mitral Valve Regurgitation in Klippel-Feil Syndrome With Related Thoracic Deformity.

Klippel-Feil syndrome, characterized by congenital fusion of any 2 or more cervical vertebrae, is a rare disorder in which skeletal and other organ system-related abnormalities have been reported. This article reports a case of mitral valve regurgitation in a patient with Klippel-Feil syndrome and related thoracic deformity who underwent mitral valvuloplasty. Postoperatively, the mitral valve regurgitation disappeared, and there has been no recurrence for 3 years. This case highlights mitral valvuloplasty via median sternotomy as an excellent treatment for mitral valve regurgitation in a patient with thoracic deformity related to Klippel-Feil syndrome.

Revealing an Uncommon Presentation of Chiari I Malformation With Diverse Craniovertebral Anomalies in the Absence of Syringomyelia and Atlanto-Occipital Subluxation: A Case Report.

A Chiari I malformation is a frequently encountered anomaly of the posterior fossa, occurring in a notable percentage of the population. It often coexists with various other craniovertebral junction abnormalities, albeit less frequently with Klippel-Feil syndrome. Interestingly, the majority of individuals with Chiari I malformation do not exhibit any symptoms. We present a rare case of a 25-year-old male with chronic neck and occipital pain, along with progressive weakness and sensory disturbances in all four limbs, urinary urgency, and elevated left shoulder. Examination unveiled spasticity, weakness, and brisk reflexes. On extensive radiological evaluation (X-ray, CT, and MRI), findings revealed various anomalies in the craniovertebral junction, including complete atlanto-occipital assimilation, basilar invagination, and platybasia. Furthermore, cervical segmentation abnormalities indicative of Klippel-Feil syndrome were observed, along with Sprengel's deformity. MRI confirmed Chiari I malformation with tonsillar herniation and myelomalacia, as well as compression at the cervico-medullary junction. This patient underwent a surgical procedure that included transoral odontoidectomy combined with occipito-cervical fixation, after which a good clinical response was observed. It emphasizes the necessity of radiological imaging for the diagnosis of Chiari and other associated abnormalities in the craniovertebral junction.

White Cord Syndrome Following Cervical Surgery in a Patient With Klippel-Feil Syndrome: A Case Report.

White cord syndrome is a rare entity, as there are very few cases described in the current literature. Postoperative MRI examination reveals cord intrinsic changes, including edema and ischemia. It is also described as a reperfusion injury of the spinal cord. This report depicts a rare case of "white cord syndrome" with tetraplegia after posterior laminectomy and fusion of the cervical spine in a patient with Klippel-Feil syndrome. A 33-year-old male patient with Klippel-Feil syndrome presented to our department with cervical myelopathy, claudication, deteriorating neurological status, imbalance, and lower limb spasticity. Due to kyphotic malformation of the cervical spine, a two-stage surgical intervention was scheduled. The patient first underwent anterior spinal fusion of C4-C6 with corpectomy of C5, where many anatomical and visceral differentiations were signed, so the surgical team was enhanced by a vascular surgeon. The postoperative period was uneventful and the patient was discharged after a week of hospitalization without any neurological deterioration. A second surgical intervention was scheduled after two months where laminectomy of C5-C7 and posterior fusion of C5-T1 were carried out. However, due to intraoperative spinal instability and various anatomical spinal variations, a third surgery, which would be occipitocervical fusion, was decided as the final surgical solution. During the third surgical operation, after the laminectomy of C1 to C5 and the placement of the occipital plate, the screws, and the two rods in situ, complete nullification of the intraoperative neurophysiologic control was signed. The internal fixation was removed immediately, the wake-up test revealed tetraplegia below C5, and the patient was transferred to the ICU. Immediate MRI revealed no spinal cord hematoma; however, spinal cord edema was present. The patient underwent a tracheostomy and remained quadriplegic with a sensory level of T8 and motor level of C5 and was discharged to a rehabilitation center. The possibility of white cord syndrome should be explained by surgeons before any cervical decompression surgery, as well as a thorough neurological examination should be performed postoperatively. The early recognition and prompt management of white cord syndrome is recommended.

Spinal Neurenteric Cyst of the Ventral Cervicothoracic Junction With Klippel-Feil Syndrome as a Symptom of Progressive Myelopathy: A Case Report.

Neurenteric cysts are rare and account for only 0.7%-1.3% of all spinal tumors. Spinal neurenteric cysts are associated with spina bifida, split-cord malformations, and Klippel-Feil syndrome, a rare congenital disorder characterized by fusion of two or more cervical vertebrae. Klippel-Feil syndrome is rarely accompanied by neurenteric cysts. In this case report, we describe a cervicothoracic junction neurenteric cyst associated with Klippel-Feil syndrome in a 30-year-old man who presented with a 2-month history of neck pain with radiation of pain into both arms and a 1-month history of weakness in the left arm. Magnetic resonance imaging (MRI) of the spine revealed an expansive intradural extramedullary cystic lesion anterior to the spinal cord at the cervicothoracic junction. The neurenteric cyst was removed using an anterior approach, accompanied by C5-C6 corpectomy. The patient's condition improved postoperatively, and he was discharged after postoperative MRI. Spinal neurenteric cysts should be considered in the differential diagnosis in cases of vertebral developmental abnormalities concurrent with intraspinal cysts.

Transient binocular vision loss and pain insensitivity in Klippel-Feil syndrome: a case report.

BACKGROUND: Klippel-Feil syndrome is a rare congenital bone disorder characterized by an abnormal fusion of two or more cervical spine vertebrae. Individuals with Klippel-Feil syndrome exhibit diverse clinical manifestations, including skeletal irregularities, visual and hearing impairments, orofacial anomalies, and anomalies in various internal organs, such as the heart, kidneys, genitourinary system, and nervous system. CASE PRESENTATION: This case report describes a 12-year-old Pashtun female patient who presented with acute bilateral visual loss. The patient had Klippel-Feil syndrome, with the typical clinical triad symptoms of Klippel-Feil syndrome, along with Sprengel's deformity. She also exhibited generalized hypoalgesia, which had previously resulted in widespread burn-related injuries. Upon examination, bilateral optic disc swelling was observed, but intracranial pressure was found to be normal. Extensive investigations yielded normal results, except for hypocalcemia and low vitamin D levels, while parathyroid function remained within the normal range. Visual acuity improved following 2 months of calcium and vitamin D supplementation, suggesting that the visual loss and optic nerve swelling were attributed to hypocalcemia. Given the normal parathyroid function, it is possible that hypocalcemia resulted from low vitamin D levels, which can occur after severe burn scarring. Furthermore, the patient received a provisional diagnosis of congenital insensitivity to pain on the basis of the detailed medical history and the findings of severe and widespread loss of the ability to perceive painful stimuli, as well as impaired temperature sensation. However, due to limitations in genetic testing, confirmation of the congenital insensitivity to pain diagnosis could not be obtained. CONCLUSION: This case highlights a rare presentation of transient binocular vision loss and pain insensitivity in a patient with Klippel-Feil syndrome, emphasizing the importance of considering unusual associations in symptom interpretation.

PUF60 loss-of-function with normal cognition should be considered in the differential diagnosis of Klippel-Feil syndrome.

Klippel-Feil syndrome (KFS) has a genetically heterogeneous phenotype with six known genes, exhibiting both autosomal dominant and autosomal recessive inheritance patterns. PUF60 is a nucleic acid-binding protein, which is involved in a number of nuclear processes, including pre-mRNA splicing, apoptosis, and transcription regulation. Pathogenic variants in this gene have been described in Verheij syndrome due to either 8q24.3 microdeletion or PUF60 single-nucleotide variants. PUF60-associated conditions usually include intellectual disability, among other findings, some overlapping KFS; however, PUF60 is not classically referred to as a KFS gene. Here, we describe a 6-year-old female patient with clinically diagnosed KFS and normal cognition, who harbors a heterozygous de novo variant in the PUF60 gene (c.1179del, p.Ile394Serfs*7). This is a novel frameshift variant, which is predicted to result in a premature stop codon. Clinically, our patient demonstrates a pattern of malformations that matches reported cases of PUF60 variants; however, unlike most others, she has no clear learning difficulties. In light of these findings, we propose that PUF60 should be considered in the differential diagnosis of KFS and that normal cognition should not exclude its testing.

Molecular landscape of congenital vertebral malformations: recent discoveries and future directions.

Vertebral malformations (VMs) pose a significant global health problem, causing chronic pain and disability. Vertebral defects occur as isolated conditions or within the spectrum of various congenital disorders, such as Klippel-Feil syndrome, congenital scoliosis, spondylocostal dysostosis, sacral agenesis, and neural tube defects. Although both genetic abnormalities and environmental factors can contribute to abnormal vertebral development, our knowledge on molecular mechanisms of numerous VMs is still limited. Furthermore, there is a lack of resource that consolidates the current knowledge in this field. In this pioneering review, we provide a comprehensive analysis of the latest research on the molecular basis of VMs and the association of the VMs-related causative genes with bone developmental signaling pathways. Our study identifies 118 genes linked to VMs, with 98 genes involved in biological pathways crucial for the formation of the vertebral column. Overall, the review summarizes the current knowledge on VM genetics, and provides new insights into potential involvement of biological pathways in VM pathogenesis. We also present an overview of available data regarding the role of epigenetic and environmental factors in VMs. We identify areas where knowledge is lacking, such as precise molecular mechanisms in which specific genes contribute to the development of VMs. Finally, we propose future research avenues that could address knowledge gaps.

Chiari type III malformation associated with Klippel-Feil syndrome, a case report with a narrative review of the literature.

BACKGROUND: Chiari malformation type III (CM III), a rare hindbrain anomaly, often presents with various concurrent anomalies. This paper reports a unique case of CM III associated with Klippel-Feil syndrome (KFS), a condition previously unreported in Saudi Arabia and documented in only one other case globally in Turkey. This study aims to share insights into the unusual association between CM III and KFS, considering their close embryological development and involvement in the craniocervical junction. METHODOLOGY: The study presents a case of a 2.5-year-old female diagnosed with CM III and KFS. Diagnostic tools such as ultrasound, CT scans, MRI, and physical examinations were used to confirm the patient's condition. Surgical interventions, including decompression and encephalocele repair, were performed. RESULTS: Successful surgical interventions, including encephalocele repair and duraplasty, were carried out. Follow-up visits indicated a stable condition, marked improvement in lower limb strength, and the patient's ability to walk with assistance. CT follow-up affirmed a satisfactory surgical outcome. CONCLUSION: This case study illustrates the potential for an optimistic prognosis in CM III, even when accompanied by complex conditions such as KFS, through early diagnosis and intervention. It underscores the significance of antenatal screening for effective care planning and calls for further research and publications due to the rarity of this association. These findings contribute to our understanding of CM III and its related conditions, emphasizing the need for open-minded consideration of potential embryological associations.

A Consultation for Pediatric Neck Mass Resulting in a Rare Diagnosis of Klippel-Feil Syndrome: A Case Report.

Klippel-Feil syndrome (KFS) is a rare congenital cervical vertebrae fusion syndrome characterized by the clinical triad of low posterior hairline, limited head and neck range of motion, and short neck. The gene defects described with this syndrome are involved in the maturation and differentiation of bone during embryological development. As such, related defects seen in patients with KFS include genitourinary anomalies, cardiac defects, neurological abnormalities, and other musculoskeletal anomalies. Patients with this syndrome should be worked up for these related malformations, evaluated for risk of comorbidities, and educated on avoiding contact sports or activities that may put the cervical spine at risk for trauma. The case report here describes a pediatric patient who presents to the outpatient otolaryngologist complaining of a pediatric neck mass. Workup of the mass, including imaging, revealed a diagnosis of Klippel-Feil syndrome. The presentation of this case highlights the importance of maintaining KFS on the list of possible diagnoses along with scoliosis, synostosis syndrome, and Wildervanck syndrome for the otolaryngologist working up a neck mass and the role making an early diagnosis can have in preventing patient morbidity and mortality.