Giant cell lesions in noonan syndrome: case report and review of the literature

Traumatic giant cell tumor of rib: A case report

BACKGROUND

Giant cell tumor (GCT) of the anterior rib origin is extremely rare. We report the first case of trauma-induced GCT of the rib.

CASE SUMMARY

A 22-year-old female developed a mass over the right anterior chest wall with pain 3 mo after a falling injury with blunt trauma of the right chest wall. Chest computed tomography (CT) showed a tumor originating from the right 6th rib with bony destruction, and a CT-guided needle biopsy revealed a GCT. We completely resected the tumor with chest wall and performed reconstruction. The pathological diagnosis was GCT of the bone. Twelve months after surgery, no signs of recurrence were observed.

CONCLUSION

GCT of the rib after trauma has not been reported. Meticulous history-taking and image evaluation are essential for the differential diagnosis of unusual chest wall tumors.

Protein tyrosine phosphatases in skeletal development and diseases

Skeletal development and homeostasis in mammals are modulated by finely coordinated processes of migration, proliferation, differentiation, and death of skeletogenic cells originating from the mesoderm and neural crest. Numerous molecular mechanisms are involved in these regulatory processes, one of which is protein posttranslational modifications, particularly protein tyrosine phosphorylation (PYP). PYP occurs mainly through the action of protein tyrosine kinases (PTKs), modifying protein enzymatic activity, changing its cellular localization, and aiding in the assembly or disassembly of protein signaling complexes. Under physiological conditions, PYP is balanced by the coordinated action of PTKs and protein tyrosine phosphatases (PTPs). Dysregulation of PYP can cause genetic, metabolic, developmental, and oncogenic skeletal diseases. Although PYP is a reversible biochemical process, in contrast to PTKs, little is known about how this equilibrium is modulated by PTPs in the skeletal system. Whole-genome sequencing has revealed a large and diverse superfamily of PTP genes (over 100 members) in humans, which can be further divided into cysteine (Cys)-, aspartic acid (Asp)-, and histidine (His)-based PTPs. Here, we review current knowledge about the functions and regulatory mechanisms of 28 PTPs involved in skeletal development and diseases; 27 of them belong to class I and II Cys-based PTPs, and the other is an Asp-based PTP. Recent progress in analyzing animal models that harbor various mutations in these PTPs and future research directions are also discussed. Our literature review indicates that PTPs are as crucial as PTKs in supporting skeletal development and homeostasis.

A Unique Case of Aggressive Central Giant Cell Granuloma in a 10-Year-Old Boy With 16p13.11 Microdeletion Syndrome

Central giant cell granuloma (CGCG) is a rare disease characterized by sporadic, benign, intraosseous mandibular lesions of unknown etiology. Histologically, these lesions are indistinguishable from brown tumors of hyperparathyroidism and cherubism, and occasionally have been associated with different syndromes raising a question for genetic etiology. The CGCG has varied presentation ranging from nonaggressive and indolent to aggressive, destructive, and recurrent, often posing diagnostic and therapeutic challenges. Herein, we present the first case of a 10-year-old boy with CGCG and 16p13.11 microdeletion syndrome, highlight the diagnostic challenges inherent to this heterogeneous disorder, and discuss the genetics and treatment approaches of these complex lesions.

Association between pectus excavatum and congenital genetic disorders: A systematic review and practical guide for the treating physician

BACKGROUND

Pectus excavatum (PE) could be part of a genetic disorder, which then has implications regarding comorbidity, the surgical correction of PE, and reproductive choices. However, referral of a patient presenting with PE for genetic analysis is often delayed because additional crucial clinical signs may be subtle or even missed in syndromic patients. We reviewed the literature to inventory known genetic disorders associated with PE and create a standardized protocol for clinical evaluation.

METHODS

A systematic literature search was performed in electronic databases. Genetic disorders were considered associated with PE if studies reported at least five cases with PE. Characteristics of each genetic disorder were extracted from the literature and the OMIM database in order to create a practical guide for the clinician.

RESULTS

After removal of duplicates from the initial search, 1632 citations remained. Eventually, we included 119 full text articles, representing 20 different genetic disorders. Relevant characteristics and important clinical signs of each genetic disorder were summarized providing a standardized protocol in the form of a scoring list. The most important clinical sign was a positive family history for PE and/or congenital heart defect.

CONCLUSIONS

Twenty unique genetic disorders have been found associated with PE. We have created a scoring list for the clinician that systematically evaluates crucial clinical signs, thereby facilitating decision making for referral to a clinical geneticist.

RASopathies: The musculoskeletal consequences and their etiology and pathogenesis

The RASopathies comprise an ever-growing number of clinical syndromes resulting from germline mutations in components of the RAS/MAPK signaling pathway. While multiple organs and tissues may be affected by these mutations, this review will focus on how these mutations specifically impact the musculoskeletal system. Herein, we review the genetics and musculoskeletal phenotypes of these syndromes in humans. We discuss how mutations in the RASopathy syndromes have been studied in translational mouse models. Finally, we discuss how signaling molecules within the RAS/MAPK pathway are involved in normal and abnormal bone biology in the context of osteoblasts, osteoclasts and chondrocytes.

Multiple versus solitary giant cell lesions of the jaw: Similar or distinct entities?

The majority of giant cell lesions of the jaw present as a solitary focus of disease in bones of the maxillofacial skeleton. Less frequently they occur as multifocal lesions. This raises the clinical dilemma if these should be considered distinct entities and therefore each need a specific therapeutic approach. Solitary giant cell lesions of the jaw present with a great diversity of symptoms. Recent molecular analysis revealed that these are associated with somatic gain-of-function mutations in KRAS, FGFR1 or TRPV4 in a large component of the mononuclear stromal cells which all act on the RAS/MAPK pathway. For multifocal lesions, a small group of neoplastic multifocal giant cell lesions of the jaw remain after ruling out hyperparathyroidism. Strikingly, most of these patients are diagnosed with jaw lesions before the age of 20 years, thus before the completion of dental and jaw development. These multifocal lesions are often accompanied by a diagnosis or strong clinical suspicion of a syndrome. Many of the frequently reported syndromes belong to the so-called RASopathies, with germline or mosaic mutations leading to downstream upregulation of the RAS/MAPK pathway. The other frequently reported syndrome is cherubism, with gain-of-function mutations in the SH3BP2 gene leading through assumed and unknown signaling to an autoinflammatory bone disorder with hyperactive osteoclasts and defective osteoblastogenesis. Based on this extensive literature review, a RAS/MAPK pathway activation is hypothesized in all giant cell lesions of the jaw. The different interaction between and contribution of deregulated signaling in individual cell lineages and crosstalk with other pathways among the different germline- and non-germline-based alterations causing giant cell lesions of the jaw can be explanatory for the characteristic clinical features. As such, this might also aid in the understanding of the age-dependent symptomatology of syndrome associated giant cell lesions of the jaw; hopefully guiding ideal timing when installing treatment strategies in the future.

Rapid detection by hydrops panel of Noonan syndrome with PTPN11 mutation (p.Thr73Ile) and persistent thrombocytopenia

BACKGROUND

Nonimmune hydrops fetalis (NIHF) is still a challenging diagnosis. The differential diagnosis is extensive and the success of identifying a cause depends on the thoroughness of efforts to establish a diagnosis. For the early diagnosis of NIHF, a virtual gene panel diagnostic tool was developed. The female premature baby in question was delivered via emergency cesarean at 30 + 1 weeks of gestational age (GA) due to rapidly developing NIHF to a healthy mother. The family history was noncontributory.

METHODS

DNA of the family was extracted and sequenced by the virtual hydrops panel with whole-exome sequencing.

RESULTS

The hydrops panel revealed Noonan syndrome (NS) with a germline mutation in PTPN11 c.218C>T (p.Thr73Ile).

CONCLUSION

The diagnosis of our patient was rapidly confirmed by the hydrops panel. The variant of c.218C>T (p.Thr73Ile) has not yet been described in literature relating to NIHF. Only a few case reports of this variant are known. This particular mutation is associated with Noonan syndrome, congenital heart defect and persistent thrombocytopenia. Few reveal juvenile myelomonocytic leukemia.

Noonan syndrome with multiple Giant cell lesions, management and treatment with surgery and interferon alpha-2a therapy: Case report

We report the case of a 14-year-old girl that was referred to the maxillo facial surgery unit at age 11 years because she exhibited swelling in the right side of her maxilla and right mandible. After a conservative surgery, she started with interferon alpha-2a to avoid recurrence. She has remained in treatment with successful results during her follow up. Considerable reduction of both maxilla and mandible lesions and bone fill have been documented. In addition, her clinical history and phenotype were suggestive of Noonan syndrome. She has short stature, broad and short neck; hypertelorism (increased distance between the eyes); downslanting palpebral fissures; sparse eyebrows and eyelashes; posteriorly rotated ears with fleshy lobes; follicular keratosis over the face, and developmental delay. Her karyotype was 46, XX. Molecular analysis of RAS/MAPK pathway genes showed a SOS1 amino acid substitution of arginine to lysine at position 552 (p.R552K). This case presents the infrequent condition of Noonan syndrome with multiple giant cell lesions (NS/MGCL) that would be the first patient as far as we know treated with surgery and interferon alpha-2a for her giant cell lesions.

Maxillary Giant Cell Granuloma: A Long-Term Follow-Up

This is a case of a 32-year-old female with a known diagnosis of Turner syndrome who presented with complaints of chronic progressive right-sided facial pain and sinus pressure, and who was afebrile. On physical examination, there was eye proptosis on the right and significant increased fullness in the right infraorbital and maxillary regions. Computed tomography and magnetic resonance imaging demonstrated a large expansile space-occupying lesion in the right maxillary area, that histologically turned out to be a giant cell reparative granuloma. The lesion was completely removed and of interest, the patient was followed up both clinically and on imaging for 10 years with no signs of recurrence. A discussion on this entity, as well the clinical and imaging differential diagnoses, is carried out.

Maxillary Giant Cell Granuloma: A Long-Term Follow-Up

A case of a 32-year-old female with a known diagnosis of Turner syndrome who presented with complaints of chronic progressive right-sided facial pain and sinus pressure and who was afebrile. On physical examination, there was eye proptosis on the right and significant increased fullness in the right infraorbital and maxillary regions. Computed tomography and magnetic resonance imaging demonstrated a large expansile space-occupying lesion in the right maxillary area that histologically turned out to be a giant cell reparative granuloma. The lesion was completely removed, and of interest, the patient was followed up both clinically and on imaging for 10 years with no signs of recurrence. A discussion on this entity, as well the clinical and imaging differential diagnoses, is discussed.

Craniofacial and cutaneous findings in Noonan, Costello and LEOPARD syndromes

Noonan, Costello and LEOPARD syndromes belong to a family of cardiofaciocutaneous disorders and share common genetic traits. As they are associated with a germline mutation in genes encoding proteins involved in RAS/MAPK, patients suffering from these syndromes are at a greater risk of cancer and abnormal myelopoiesis in infancy. Patients with cardio faciocutaneous syndromes share some clinically overlapping syndromes, therefore differential diagnosis can be problematic. In this paper we aim at demonstrating distinctive craniofacial and cutaneous manifestations of Noonan, Costello and LEOPARD syndromes which can be useful for clinicians who aim at treatment of children with rare diseases.

Noonan syndrome - a new survey

Noonan syndrome (NS) is an autosomal dominant disorder with vast heterogeneity in clinical and genetic features. Various symptoms have been reported for this abnormality such as short stature, unusual facial characteristics, congenital heart abnormalities, developmental complications, and an elevated tumor incidence rate. Noonan syndrome shares clinical features with other rare conditions, including LEOPARD syndrome, cardio-facio-cutaneous syndrome, Noonan-like syndrome with loose anagen hair, and Costello syndrome. Germline mutations in the RAS-MAPK (mitogen-activated protein kinase) signal transduction pathway are responsible for NS and other related disorders. Noonan syndrome diagnosis is primarily based on clinical features, but molecular testing should be performed to confirm it in patients. Due to the high number of genes associated with NS and other RASopathy disorders, next-generation sequencing is the best choice for diagnostic testing. Patients with NS also have higher risk for leukemia and specific solid tumors. Age-specific guidelines for the management of NS are available.

Chronic pain in Noonan Syndrome: A previously unreported but common symptom

Noonan syndrome (NS) is a multiple malformation syndrome characterized by pulmonic stenosis, cardiomyopathy, short stature, lymphatic dysplasia, craniofacial anomalies, cryptorchidism, clotting disorders, and learning disabilities. Eight genes in the RAS/MAPK signaling pathway are implicated in NS. Chronic pain is an uncommon feature. To investigate the prevalence of pain in NS, we distributed a two-part questionnaire about pain among NS individuals at the Third International Meeting on Genetic Syndromes of the Ras/MAPK Pathway. The first part of the questionnaire queried demographic information among all NS participants. The second part was completed by individuals with chronic pain. Questions included musculoskeletal problems and clinical features of pain. Forty-five questionnaires were analyzed; 53% of subjects were female. Mean age was 17 (2-48) years; 47% had a PTPN11 mutation. Sixty-two percent (28/45) of individuals with NS experienced chronic pain. There was a significant relationship between prevalence of pain and residing in a cold climate (P = 0.004). Pain occurred commonly in extremities/joints and head/trunk, but more commonly in extremities/joints (P = 0.066). Subjects with hypermobile joints were more likely to have pain (P = 0.052). Human growth hormone treatment was not statistically significant among subjects without chronic pain (P = 0.607). We conclude that pain is a frequent and under-recognized clinical feature of NS. Chronic pain may be associated with joint hypermobility and aggravated by colder climate. Our study is a preliminary investigation that should raise awareness about pain as a common symptom in children and adults with NS.

The role of SH3BP2 in the pathophysiology of cherubism

Cherubism is a rare bone dysplasia that is characterized by symmetrical bone resorption limited to the jaws. Bone lesions are filled with soft fibrous giant cell-rich tissue that can expand and cause severe facial deformity. The disorder typically begins in children at ages of 2-5 years and the bone resorption and facial swelling continues until puberty; in most cases the lesions regress spontaneously thereafter. Most patients with cherubism have germline mutations in the gene encoding SH3BP2, an adapter protein involved in adaptive and innate immune response signaling. A mouse model carrying a Pro416Arg mutation in SH3BP2 develops osteopenia and expansile lytic lesions in bone and some soft tissue organs. In this review we discuss the genetics of cherubism, the biological functions of SH3BP2 and the analysis of the mouse model. The data suggest that the underlying cause for cherubism is a systemic autoinflammatory response to physiologic challenges despite the localized appearance of bone resorption and fibrous expansion to the jaws in humans.