Locally aggressive fibrous dysplasia mimicking malignancy: a report of four cases and review of the literature

Successful surgical management of polyostotic costal fibrous dysplasia-a case report

Polyostotic costal fibrous dysplasia is a rare cause of chest pain. This report describes a young male with polyostotic fibrous dysplasia with partial vertebral involvement, who presented to us with disabling pain refractory to medical therapy. He was managed successfully with resection of dysplastic ribs, while conserving the asymptomatic vertebral lesion.

Mazabraud's syndrome in female patients: Two case reports

BACKGROUND

Mazabraud's syndrome (MS) is a rare and slowly progressive benign disease characterized by the concurrent presence of fibrous dysplasia of bone and intramuscular myxoma, and is thought to be associated with mutations of the GNAS gene. To date, only about 100 cases of MS have been reported in the literature, but its standard treatment strategy remains unclear.

CASE SUMMARY

We report two cases of MS in young women who underwent different treatments based on their symptoms and disease manifestations. The first patient, aged 37, received internal fixation and intravenous bisphosphonate for a pathological fracture of the right femoral neck, excision of a right vastus medialis myxoma was subsequently performed for pain control, and asymptomatic psoas myxomas were monitored without surgery. Genetic testing confirmed a GNAS gene mutation in this patient. The second patient, aged 24, underwent right vastus intermedius muscle myxoma resection, and conservative treatment for fibrous dysplasia of the ilium. These patients were followed-up for 17 months and 3 years, respectively, and are now in a stable condition.

CONCLUSION

Various treatments have been selected for MS patients who suffer different symptoms. The main treatment for myxomas is surgical resection, while fibrous dysplasia is selectively treated if the patient experiences pathological fracture or severe pain. However, given the documented instances of malignant transformation of fibrous dysplasia in individuals with MS, close follow-up is necessary.

A Case Report of Craniofacial Intraosseous Xanthoma in a Patient Seeking Facial Feminization Surgery

BACKGROUND

Fibrous dysplasia (FD) is a benign developmental disorder of the bone that causes normal skeletal tissue to be replaced by excess fibrous tissue and poorly differentiated osteoblasts. Intraosseous xanthomas are benign intraosseous tumor growths characterized microscopically by the presence of lipid-laden foamy histiocytes, often with cortical expansion or disruption. Although FD commonly occurs in craniofacial bones, primary intraosseous xanthomas of the skull or facial skeleton are extremely rare. Although 2 distinct conditions, each may be difficult to differentiate on CT imaging when occurring in the facial skeleton.

METHODS

We report a case of an incidental finding on craniofacial CT of a frontal bone lesion originally thought to be FD. The finding was in a 55-year-old transgender woman who was assigned male at birth before receiving multiprocedural facial feminization surgery.

RESULTS

The clinical features, radiological findings, and treatment are discussed. Postoperatively, the patient had no sequelae secondary to facial feminization surgery or to the orbital lesion biopsy procedure. Bone graft appeared stable on CT imaging, although FD did not appear to resolve completely.

CONCLUSIONS

Diagnosis of such lesions is challenging and may require both radiographic and histopathologic assessment. As in the case of this patient, intraosseous xanthomas may also be misdiagnosed as other benign lesions such as FD. In most known cases, surgical intervention leads to complete resolution without recurrence of the lesion.

A young woman with atypical McCune-Albright syndrome and the difficult road to recovery: a case report

Background

Fiber dysplasia is a complex condition that presents with various clinical manifestations, such as deformity, dysfunction, pathological fractures, and endocrine disorders. McCune-Albright syndrome (MAS) is a rare subtype of fiber dysplasia. This article reports a case of atypical McCune-Albright syndrome in a patient with a femoral neck fracture.

Case presentation

A patient with atypical McCune-Albright syndrome sustained a right femoral neck fracture and underwent multiple treatments, including total hip replacement, intravenous infusion of zoledronic acid, oral calcium supplementation, right supracondylar osteotomy, orthopedic surgery, plate and screw internal fixation for a left femoral shaft fracture, and removal of the right femoral plate. The patient also developed a submaxillary infection complicated by mandibular osteonecrosis.

Conclusion

Patients with MAS may experience rare complications as a result of their unique condition, regardless of whether they receive drug or surgical treatment. Therefore, personalized drug regimens and feasible surgical options are necessary.

Fibrous Dysplasia With Atypical Bilateral Upper Extremity Pattern

ABSTRACT

Fibrous dysplasia (FD) typically presents unilaterally in the lower limbs, or in the skull, mandible, or pelvis. Bilateral presentation is rarely reported. Most cases are diagnosed in the teens with 75% of patients diagnosed before the age of 30 years. In this case, a 63-year-old woman with suspected diagnosis of malignancy was referred to 99mTc-MDP scan and found to have polyostotic FD in bilateral upper extremities. Nuclear medicine can play an important role in diagnosing FD cases with atypical presentation and help risk stratification for more aggressive transformation.

Multimodal imaging diagnosis for bone fibrous dysplasia malignant transformation: A case report

Fibrous dysplasia of bone (FDB) is a rare benign condition in which fibrous tissue replaces normal bone architecture. FDB rarely undergoes malignant transformation, but there are reports of locally aggressive fibrous dysplasia with cortical destruction and soft tissue extension. Diagnosis of FDB malignant transformation is not easy, especially in monostotic form, because of the overlap in imaging features of locally aggressive fibrous dysplasia and fibrous dysplasia with malignant transformation. The present case study reports a rare case of FDB in a 23-year-old man with polyostotic fibrous dysplasia arising in the left side of the pelvis and lower limb bones with partial transformation to fibrosarcoma. This study explored the multimodal imaging features of FDB malignant transformation, to achieve early detection and improve diagnostic accuracy of local FDB aggressiveness and its malignant transformation.

Malignant Sarcomatous Degeneration of Craniofacial Fibrous Dysplasia

BACKGROUND

Fibrous dysplasia (FD) is an uncommon bone disease characterized by the replacement of normal bone architecture with abnormal fibro-osseous connective tissue. Here, we discuss 2 cases of craniofacial FD, with malignant sarcomatous degeneration - a rare and morbid complication of the disease.

CASE HISTORY

Two cases of craniofacial FD with malignant degeneration are presented. In the first, a 68-year-old male with a history of FD presented with acutely worsening left-sided facial pain and V2 and V3 hypoesthesia. Imaging findings suggested a large infratemporal fossa mass with biopsy demonstrating sarcomatous degeneration. Radical craniofacial resection achieved a gross total resection with likely microscopic disease. The patient was unable to tolerate adjuvant chemotherapy or radiation and succumbed to his disease 13 months following surgery.In the second case, a 36-year-old male with McCune-Albright Syndrome and craniofacial FD presented with acutely worsening left-sided headaches and midface hypoesthesia. Imaging revealed a heterogenous and expansile lesion with erosive changes in the left nasal cavity and infratemporal fossa. Pathology was suggestive of low grade sarcomatous degeneration. Given the extensive involvement of the skull base, the tumor was deemed unresectable, and the patient soon died following initiation of chemotherapy.

CLINICAL RELEVANCE

Malignant sarcomatous transformation is a rare and challenging complication of craniofacial FD. Indolent onset, advanced spread at time of presentation, and close relationship with vital neurovascular structures are all hurdles for the treating clinician. The entity poses a diagnostic dilemma, as pathological analysis can be equivocal and may mimic nonmalignant processes, such as locally aggressive FD.

Fibrous Dysplasia of the Temporal Bone: a Demanding Entity for Radiologists and ENT Surgeons

Fibrous dysplasia (FD) is a rare, benign, chronic, slowly progressive bone disorder characterized by the replacement of normal bone and bone marrow by fibrous tissue, leading to deformity, pain and functional impairment. It was considered a disease of unknown etiology, uncertain pathogenesis and diverse histopathology. It was later discovered that was caused by a non-heritable activating mutation in the á-subunit gene of the stimulatory G-protein coding gene. Temporal bone involvement is the least frequently reported type, especially in children. The purpose of the current manuscript was to report a rare case of fibrous dysplasia of the left temporal bone of a 17-year-old child who came to the emergency room of our hospital with otalgia and progressive hearing loss on the left ear.

Polyostotic Fibrous Dysplasia Complicated by Pathological Fracture of Right Femoral Shaft with Nonunion: A Case Report

Introduction

Fibrous dysplasia is a benign fibrous bone tumor that accounts for 5% to 10% of benign bone tumors. It can manifest as simple fibrous dysplasia (70%–80%), polyostotic fibrous dysplasia (20%–30%), with approximately the same incidence in men and women. We report a patient with a rare case of multiple fibrous dysplasia combined with proximal femoral shepherd deformity with pathological fracture of the femoral shaft complicated by nonunion. It is necessary to understand the disease in more detail to avoid overtreatment of benign lesions or misdiagnosis of malignant tumors and other diseases.

Case presentation

A 58-year-old man with polyostotic fibrous dysplasia, bilateral proximal femur deformity, Shepherd’s angle deformity, right femoral shaft pathological fracture complicated by nonunion, we under fluoroscopy, in the obvious proximal fracture, take osteotomy, and process the shape of the cut bone fragment to adapt it to the corrected force line, and then restore it back to its original position, using intramedullary nailing technology complete the operation. Three months after the operation, he came to the hospital for re-examination, and an X-ray of the right femur was taken. It was found that the fractured end had a tendency to heal. The patient was instructed to gradually bear weight. After six months of re-examination, the patient could walk with a walker. One year after the operation, the patient could walk without a walker and take care of himself at home. However, there was still stretch-like pain in the right lower back, but it was tolerable.

Conclusions

For patients with polyostotic fibrous dysplasia combined with proximal femoral shepherd deformity and pathological fracture of the femoral shaft with nonunion, osteotomy combined with intramedullary nailing is a simple and convenient way to correct the deformity and obtain correct fracture alignment.

Fibrous dysplasia mimicking bone metastasis in nasopharyngeal carcinoma: a case report and literature review

Fibrous dysplasia of bone (FDB) is a rare bone disease that may be misdiagnosed as bone metastasis in terms of some symptoms and imaging features. Therefore, the differential diagnosis between FDB and bone metastasis may be a challenge. To our knowledge, there are no reports in the literature to date regarding concomitant nasopharyngeal carcinoma (NPC) with FDB. The aim of this study was to report the case of a NPC patient with FDB, to highlight correct diagnosis and treatment. A 28-year-old young woman was investigated for accidental nasal bleeding. A mass on the right neck and local pain on right femur, and she was submitted to a standard imaging examination suggesting the presence of a solitary right femur metastasis from NPC. Then the patient was submitted to four cycles of chemotherapy, with a partial response (PR) for the mass in neck but no change in the bone metastasis. Because the bone lesion was single, pathologic biopsy was taken to confirm diagnosis. Surprisingly, it was a FDB instead of tumor. At five-year follow-up, she is free of recurrent disease. In this case, we believe that although NPC with FDB is rare, it should not be omitted when bone metastasis is suspected, especially when the metastasis is solitary, because it is crucial for diagnostic staging and treatment choice.

Pathological Fracture of the Tibia in a Monostotic Anterior Cortical Fibrous Dysplasia: Hybrid Fixation with UnicorticalOsteoperiosteal Non-Vascularized Fibula Graft - A Case Report

Introduction

Fibrous Dysplasia is a relatively rare Musculoskeletal disorders in which there is a defect in remodelling of immature bone to mature lamellar bone. Fibrous Dysplasia was first described by Von Recklinghausen in 1891, but it was Lichtenstein who labelled it polyostotic Fibrous Dysplasia in 1938. Union of Pathological Fractures in a bone affected by Fibrous Dysplasia poses a difficult set of Challenges for treating Physicians.

Case Report

We Report a 24 year-old female patient with a Pathological Fracture of the Tibia in a Monostotic Anterior Cortical Fibrous Dysplasia Hybrid Fixation with a UnicorticalOsteoperisoteal Non Vascularized Fibula Graft with a follow up until the union of fracture site on computed tomography scan and complete integration of unicorticalosteoperiosteal fibular graft .

Conclusion

We provide additional and independent evidence that removal of the diseased cortex which were parts of the proximal and distal fragment and reconstruction of the defect in the cortex with a press- fitunicortical Non vascularized osteoperiosteal fibular strut graft with a hybrid fixation is a good treatment modality for monostotic fibrous dysplasia. Hybrid fixation includes retrograde intramedullary transarticular rodding extending across the subtalar and ankle joint into the tibia and augmentation of the primary fixation with a mono-planar rail Fixation in compression mode.

Continued growth of locally aggressive fibrous dysplasia of 22 years duration after reaching adulthood: a case report

Fibrous dysplasia generally stops growing when patients reach adulthood. Locally aggressive fibrous dysplasia is an extremely rare subtype of fibrous dysplasia that is characterized by progressive enlargement after bone maturation, cortical bone destruction and soft tissue invasion but without malignant transformation. At 50 years of age, a tumor was found in the rib of a patient. The tumor gradually enlarged over time and imaging findings suggested a malignant tumor. The case was further complicated by restrictive lung disorder. Biopsies from multiple sites showed no malignant findings, and marginal resection with partial curettage was performed. The final diagnosis was locally aggressive fibrous dysplasia, and the restrictive lung disorder improved postoperatively. The natural history of the disease is also unknown. This is the first report in the literature to describe a case in which a lesion exhibited long-term growth over a period of 22 years after reaching adulthood.

Magnetic resonance imaging characteristics in patients with histopathologically proven fibrous dysplasia-a systematic review

OBJECTIVE

To examine the demographics, lesion location, and characteristic magnetic resonance imaging (MRI) findings in patients with histopathologically proven fibrous dysplasia (FD).

MATERIALS AND METHODS

A systematic literature search of the MRI findings in patients with histologically proven FD was performed. Altogether, 76 articles with 136 patients were evaluated.

RESULTS

The mean age of the patients was 35.0 + - 18.5 years (range 1 month-75 years). Fifty-eight of the cases were females, 51 males, and in 27 gender was not defined. The most common locations were craniofacial (n = 55 (40%)), long bones (n = 31 (23%)), and spine (n = 24 (18%)). The monostotic form of FD was the most common. Signal intensities (SI) on T1-weighted images were predominantly hypointense (n = 46 (37%)). The SI was highly variable on T2-weighted images with hyperintensity being most common (n = 22 (18%)). Contrast enhancement was found in 75 (55%) FD patients. Secondary aneurysmal bone cysts (ABCs) and malignant transformation in patients without prior radiotherapy was found in some patients.

CONCLUSION

Current knowledge of the MRI findings in patients with FD is based mainly on case reports. SI in patients with FD is variable and contrast enhancement is common. FD may explain etiology of spinal bone tumor in some patients. FD with malignant transformation should be considered also in patients without prior radiotherapy. Further studies are needed to clarify if FD displays specific characteristics allowing it to be distinguished from other bone tumors.

Locally aggressive monostotic fibrous dysplasia of the cervical spine mimicking malignancy: a case report and literature review

We report the case of a 30-year-old woman with histologically proven monostotic fibrous dysplasia of C2 revealed by a pathological fracture of the odontoid process. Radiological investigations showed a ground-glass mineralization of the vertebral body, a centimetric lytic area with poorly defined margins involving the inferior part of the vertebral body and inferior endplate and a fracture through an osteolytic area in the base of the odontoid process. Owing to the vertebral instability, a surgical procedure combining C0-C5 fixation and posterior bone grafting was performed. The surgical biopsy was inconclusive and pathological confirmation was finally obtained through a percutaneous needle biopsy under fluoroscopic guidance. At 26-month follow-up, the patient still experienced mild persistent cervical posterior neck pain and stiffness possibly related to a C5-6 laxity below the intervertebral fixation. This case combines three radiological findings, which are unusual in fibrous dysplasia: monostotic presentation involving the spine, some aggressive radiographic features, and a pathological fracture.

Monostotic craniofacial fibrous dysplasia: report of two cases with interesting histology

Fibrous dysplasia (FD) is a relatively rare osseous disease of unknown etiology, wherein the normal bone is replaced by collagen-rich tissue, comprising of fibroblasts and variably abundant immature woven bone. Clinically, it may involve a single bone or multiple bones. It commonly arises in the jaw bone, skull, rib, and proximal femur. Those arising in the skull and the jaw are together termed “craniofacial fibrous dysplasia.” The differential diagnosis at this location includes meningioma and metastatic carcinoma. In this report, we highlight two diagnostically challenging cases presenting with orbital swelling and headache as the main complaints. Our first case was misinterpreted as meningioma on intraoperative squash smear, and paraffin sections revealed characteristic features of FD. The second case highlights the morphological feature of non-specific cystic degeneration occurring in FD. Radiographs in such cases show cystic swelling, which is indicative of a secondary aneurysmal bone cyst.

Mutational analysis of high-grade spindle cell sarcoma of the femur in Mazabraud's syndrome

Mazabraud's syndrome is a rare disorder characterised by the association of fibrous dysplasia with intramuscular myxomas. We present a 36-year-old woman with right anterior knee pain and a buttock mass. Imaging showed aggressive bone destruction within an area of fibrous dysplasia in the right femur and a mass with myxoid signal characteristics in the right adductor region. Biopsy of the femur revealed both fibrous dysplasia and a high-grade spindle cell sarcoma. Biopsy of the adductor mass confirmed a soft-tissue myxoma. Molecular genetic analysis revealed an identical R201H substitution in the GNAS1 gene in the sarcoma, the myxoma, and also the conventional fibrous dysplasia.

Fibrous dysplasia of the jaws: Integrating molecular pathogenesis with clinical, radiological, and histopathological features

Fibrous dysplasia is a non-neoplastic developmental process that affects the craniofacial bones, characterized by painless enlargement as a result of bone substitution by abnormal fibrous tissue. Postzygotic somatic activating mutations in the GNAS1 gene cause fibrous dysplasia and have been extensively investigated, as well as being helpful in the differential diagnosis of the disease. Fibrous dysplasia may involve one (monostotic) or multiple bones (polyostotic), sporadically or in association with McCune-Albright syndrome, Jeffe-Lichenstein syndrome, or Mazabreud syndrome. This review summarizes the current knowledge on fibrous dysplasia, emphasizing the value of integrating the understanding of its molecular pathogenesis with the clinical, radiological, and histopathological features. In addition, we address important aspects related to the differential diagnosis and patient management.

Fibrous dysplasia: an unusual case of a very aggressive form with costo-vertebral joint destruction and invasion of the contralateral D7 vertebral body

Fibrous dysplasia (FD) is a benign fibro-osseous disease of the bone that may be solitary or multicentric. It is important to distinguish this type of lesion from low-grade osteosarcomas (LGOS) and from secondary sarcomas, because malignant transformation has rarely been reported. It is classically described as having a ground-glass appearance, endosteal scalloping, and thinning of the cortex. Cortical disruption is considered evidence of malignancy, but it can also be present in benign FD with aggressive behavior. We present an unusual case of aggressive FD of the 7th left rib, already diagnosed more than 22 years ago, where cortical and costo-vertebral joint disruption and 7th thoracic vertebral body involvement were not evidence of malignant behavior. From a histological perspective, FD and LGOS are similar; even if histology is of fundamental importance, the diagnosis has to be made based on the clinical and radiological aspects as well, although at imaging, differentiation between FD and LGOS can be difficult. In the present case, even though the histological examination suggested a benign lesion, the radiological examination instead consistently suggests malignancy. It is for this reason that there should be a high index of suspicion during follow-up and a new biopsy should be scheduled in case any changes occur during follow-up.

Locally Aggressive Fibrous Dysplasia Mimicking Malign Calvarial Lesion

Fibrous dysplasia is an unusual benign bone tumor. It is divided into 3 groups as monostotic, polyostotic, and craniofacial form. The authors reported an unusual patient with fibrous dysplasia with an aggressive radiologic appearance.

Mazabraud's Syndrome Mimicking Metastases on FDG PET/CT in a Patient With Colon Cancer

Mazabraud's, a syndrome consisting of fibrous dysplasia and soft tissue myxomas, is a rare disorder with less than 100 cases reported in the literature. Appearance of lesions in Mazabraud's syndrome on FDG PET/CT scan in an oncological scenario can be misinterpreted as malignancy. We present the case of a 69-year-old woman, diagnosed with metastatic colon carcinoma and suspected osseous as well as soft tissue metastases, who was later found to have concomitant Mazabraud's syndrome. This case describes the diagnostic dilemma associated with this unusual entity and importance of differentiating benign and malignant etiologies on FDG PET/CT scan.

Fibrous dysplasia imitating malignancy

Fibrous dysplasia is a benign bone disease, presenting as monostotic or polyostotic lesions, or as part of a syndrome (McCune-Albright/Mazabraud). Its clinical course shows a variegated picture and the progression of its growth is unpredictable. In the workup of 39 fibrous dysplasia cases in the cranio-facial area, four cases presented fast growth tendencies, of which two patients with McCune-Albright syndrome showed malignant-like rapid growth. This local aggressive form is extremely rare, and the concept of this issue has not been clearly defined. With regard to the speed of growth a volumetric-time analysis in one of our cases demonstrated a 74 days tumor doubling rate with an exponential growth curve. According to the literature the aggressive form presented extra-cranially mainly at an adult age, whereas its appearance in our cranio-facial patient collective was much younger. Distinguishing nonmalignant and malignant aggressive forms is difficult and highly inconsistent in the literature. We therefore implemented a quantitative growth measure analysis to define aggressive forms based on progression and speed of growth and impartial of type of FD, localization or functional incapacity. Due to our study findings and literature review we state a prevalence of an aggressive form might be possibly about 5 %.

Natural history of cranial fibrous dysplasia revealed during long-term follow-up: Case report and literature review

BACKGROUND

Fibrous dysplasia (FD) is a rare developmental disease characterized by the replacement of bone marrow with proliferating fibro-osseous tissue. There exist three forms of FD-monostotic, polyostotic, and that associated with McCune-Albright syndrome. The disease can present in different locations and with a variety of symptoms. One of the more common locations of FD occurrence is the craniofacial region. Treatment of asymptomatic FD often involves conservative management with serial imaging. Medical management with bisphosphonates is an option, though long-term efficacy data are lacking. Surgical resection is usually reserved for very large or symptomatic lesions.

CASE DESCRIPTION

We discuss the most unusual case of a 52-year-old male found to have a left pterional mass while being worked up for sinus headaches. The patient elected to follow this lesion conservatively, and imaging several years later showed obvious growth which accelerated in the last 4 years during an 18-year observational period. He ultimately underwent successful resection of an extradural and intradural FD.

CONCLUSIONS

The significant growth potential of these lesions was revealed in this patient, in whom conservative management had been adopted. Despite optimal surgical resection and outcome in this case, the importance of surveillance imaging and perhaps earlier intervention cannot be underestimated when managing cranial FD.

Xanthomatous Posttraumatic Fibro-Osseous Lesion of the Rib: A Rare and Underrecognized Entity. Case Report and Literature Review

Posttraumatic fibro-osseous lesion (PTFOL) is a rare lesion that typically affects the ribs and is probably a posttraumatic reactive process. Because PTFOL is often misdiagnosed as fibrous dysplasia, osteoid osteoma, benign fibrous histiocytoma or rib metastases, chest wall resection, leading to a significant morbidity, is the main treatment modality. We report the case of a 30-year-old male patient with no history of previous trauma presenting with chest pain. Computed tomography scan showed an eighth left rib well-defined ovoid and hypodense lesion with circumferential sclerotic margin and no cortical breakthrough. Posterolateral thoracotomy was performed and a histological diagnosis of xanthomatous posttraumatic fibro-osseous lesion of the rib was made. PTFOL is a benign lesion that should be recognized to avoid unnecessary surgical treatment and complications. We provide a summary of clinical, histopathological, and radiological aspects of PTFOL and discuss differential diagnoses.

Bone tumors of the pediatric foot: imaging appearances

Tumors of the foot are rare in children. This review illustrates radiographic, CT and MR imaging findings of foot bone tumors in children based on all cases presented in a tertiary pediatric hospital during the 15-year period of 1999-2014. This search revealed 155 tumors of the foot, 72 of the bones and 83 of the soft tissues. Osteochondroma, bone cyst and fibrous dysplasia were the most frequent benign bone lesions. Ewing sarcoma was the most common malignant osseous tumor. Some tumors showed higher prevalence in certain age ranges and others showed predilection for specific bones. Radiographs are useful for diagnosis in the majority of cases but CT and MR imaging provide additional valuable information in select cases for diagnosis and determining extent of the lesions. Radiologists should be aware of some typical imaging findings in bone tumors of the foot in order to establish diagnosis and facilitate patient management.

Implantable tissue isolation chambers for analyzing tumor dynamics in vivo

Recruitment of new blood vessels from the surrounding tissue is central to tumor progression and involves a fundamental transition of the normal, organized vasculature into a dense disarray of vessels that infiltrates the tumor. At present, studying the co-development of the tumor and recruited normal tissue is experimentally challenging because many of the important events occur rapidly and over short length scales in a dense three-dimensional space. To overcome these experimental limitations, we partially confined tumors within biocompatible and optically clear tissue isolation chambers (TICs) and implanted them in mice to create a system that is more amenable to microscopic analysis. Our goal was to integrate the tumor into a recruited host tissue - complete with vasculature - and demonstrate that the system recapitulates relevant features of the tumor microenvironment. We show that the TICs allow clear visualization of the cellular events associated with tumor growth and progression at the host-tumor interface including cell infiltration, matrix remodeling and angiogenesis. The tissue within the chamber is viable for more than a month, and the process is robust in both the skin and brain. Treatment with losartan, an angiotensin II receptor antagonist, decreased the collagen density and fiber length in the TIC, consistent with the known activity of this drug. We further show that collagen fibers display characteristic tumor signatures and play a central role in angiogenesis, guiding the migration of tethered endothelial sprouts. The methodology combines accessible methods of microfabrication with animal models and will enable more informative studies of the cellular mechanisms of tumor progression.

Mazabraud's syndrome and thyroid cancer, a very rare and confusing association: a case report

BACKGROUND

Mazabraud's syndrome is defined as the association between fibrous dysplasia and intramuscular myxomas. The syndrome was first described in 1967 and, up until now, less than 100 cases have been reported worldwide. Here we report the association between this rare syndrome and thyroid cancer. When a malignant disease occurs in a patient affected by this syndrome, the differential diagnosis between benign and malignant bone lesions should be undertaken carefully.

CASE PRESENTATION

We report the case of a 57-year-old Caucasian male, admitted for diffuse bone pain localized in the left leg and for the presence of an indolent, slow-growing mass in the left shoulder. The patient also presented with a thyroid nodule, highly suggestive of a malignancy. The radiologic examination showed multiple osteolytic lesions. The suspicion of multiple myeloma or bone metastases arising from a thyroid cancer was considered. Electrophoresis of proteins was negative and therefore excluded the diagnosis of multiple myeloma; the thyroid surgery was indicated. Thyroidectomy confirmed the papillary thyroid carcinoma, and the bone lesions were considered to be metastases from the thyroid cancer. After surgery, under thyroid-stimulated hormonal conditions, the patient underwent radioiodine therapy and a post-therapy radioiodine whole body scan. The lack of radioiodine uptake, both in the bone lesions and shoulder mass, suggested the possibility of less differentiated, non-avid radioiodine lesions, or the absence of any relation between pathologies. Considering the low level of the specific tumor marker, thyroglobulin, a bone biopsy and resection of the shoulder mass were indicated. The final diagnosis was intramuscular myxoma with polyostotic fibrous dysplasia in the deltoid muscle (Mazabraud's syndrome). A completely incidental cerebral tumor lesion was also discovered.

CONCLUSION

During the evolution of a malignant disease, Mazabraud's syndrome, known as the association of intramuscular myxoma with fibrous dysplasia, should be considered in the differential diagnosis of bone metastasis. This is the first report in the literature of Mazabraud's syndrome occurring in a patient with thyroid cancer.