Infantile Myofibromatosis of the Femoral Neck: A Case Report.

CASE: A 15-month-old boy who was being followed for developmental dysplasia of the hip because of breech presentation was discovered to have a solitary infantile myofibroma in the left femoral neck. The patient was avoiding weight-bearing on the affected extremity; thus, stabilization of the femoral neck was performed using a proximal femur locking plate. Postoperatively, he achieved all gross motor developmental milestones. CONCLUSION: This report is the first to describe a solitary infantile myofibroma in the femoral neck and demonstrates the utility of operative stabilization of these lesions.

Prenatal genetic diagnosis of disseminated infantile myofibromatosis: a case report and literature review.

BACKGROUND: Infantile myofibromatosis (IM) is a rare disorder characterized by the formation of nodules in the skin, muscle, bone, and, more rarely, visceral organs. Very few cases are detected prenatally, and the final diagnosis cannot be made until pathology is completed after birth. Here, we present a case of disseminated form IM (DFIM) with a diagnosis established on prenatal genetic grounds. CASE PRESENTATION: A woman at 23 weeks of gestation was referred for ultrasound evaluation of fetal kidney abnormality. Generalized masses in the skin and muscle of the fetus developed at 28 weeks. Prenatal genetic testing identified the pathogenic heterozygous variant c.1681C > T (p.R561C) of the PDGFRB gene inherited from the asymptomatic father. Intrauterine demise occurred at 31 weeks. Autopsy confirmed DFIM with involvement of the heart and kidney. All cases of prenatally detected IM were reviewed, revealing an association of high mortality with DFIM. CONCLUSIONS: Prenatal IM diagnosis is difficult. Initial detection is always based on ultrasound. DFIM has high mortality. The germline p.R561C mutation in PDGFRB may cause fetal demise due to severe visceral involvement of IM. Prenatal genetic testing provides a diagnosis before pathological results are available, leading to better counseling and management of pregnancy with a fetus with IM.

Giant intracranial infantile myofibromatosis of the skull base: report of two cases.

Infantile myofibromatosis is a rare and nonmalignant pediatric tumor of myofibroblastic origin that may occur in solitary or multifocal forms. Soft tissue of the head and neck, trunk, and extremities, skeleton, and viscera are usually involved. Intracranial involvement is reported to be extremely rare, and its clinical picture has been poorly characterized. We present two cases of giant infantile myofibromatosis of the skull base with intracranial involvement. The first case with prenatal diagnosis involved extensively the extradural space of the occipital region and was previously treated by chemotherapy for a previous diagnosis of hemangioperycitoma. Tumor was removed at the age of 5 months and no recurrence was observed during the 3-year follow-up. The second case in a 2-year-old baby involved the anterior cranial base, the nasal cavity, the right orbit, and presented massive involvement of the anterior cranial fossa. Surgery allowed complete removal and a recurrence-free period of 7 years after surgery. Treatment options for these unusual cases are presented and details of histological diagnosis are discussed.

Multicentric infantile myofibromatosis with extensive involvement limited to bone.

Infantile myofibromatosis (IM) is the most common benign fibrous tumor of infancy, characterized by the development of single or multiple nodules in the skin, soft tissues, bone, and/or viscera. Multicentric forms are less frequent and can affect different tissues simultaneously and their prognosis depends on their extension and visceral involvement. Rarely, these forms are limited to the skeleton, in which case the absence of extraosseous lesions makes it difficult to suspect this entity. We present the case of an infant with multiple radiolucent lesions involving the skull, ribs, spine, and long bones, discovered in a radiological study performed after a minor trauma. A broad differential diagnosis was considered based on the osteolytic and polyostotic nature of the lesions on imaging studies. This report details and illustrates the typical radiological findings in bony involvement of IM, which suggest this disorder over other diagnostic options.

Myofibroma/myofibromatosis: MDCT and MR imaging findings in 24 patients with radiological-pathological correlation.

BACKGROUND: The aim of this study was to characterize the radiological features of myofibroma on multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) and correlate the imaging findings with pathologic features. METHODS: The radiological findings of 24 patients with 29 myofibromas were retrospectively reviewed. All images were evaluated with emphasis on density, signal intensity, hypointense area, and enhancement, correlating these with pathologic findings. RESULTS: On plain MDCT scan, 4(26.7%) tumors were homogeneous isodensity, 4(26.7%) tumors were heterogeneous hyperdensity, and 7(46.7%) tumors were heterogeneous hypodensity. On contrast-enhanced MDCT scan, all tumors (9/9) showed heterogeneous enhancement with moderate in 3(33.3%) and marked in 6(66.7%) tumors, and their enhancements were higher compared to adjacent skeletal muscle (P = 0.0001). On MRI, heterogeneous slight hyperintensity, homogeneous slight hyperintensity, and heterogeneous hypointensity on T1-weighted imaging (T1WI) were observed in 14(82.3%), 1(5.9%) and 2(11.8%) tumors, respectively. On T2-weighted imaging (T2WI) and fat-suppressed (FS) T2WI, all tumors demonstrated heterogeneous hyperintensity. All tumors showed heterogeneous marked enhancement on FS contrast-enhanced T1WI. On T1WI, T2WI, FS T2WI, and FS contrast-enhanced T1WI, irregular strip or/and patchy hypointensities were found in 16(94.1%), 12(100%), 17(100%) and 17(100%) tumors, respectively, and pseudocapsule was seen in 5(29.4%) tumors. The hypointensities and pseudocapsule on MRI were exactly corresponding to pathological interlacing collagen fibers and fibrosis. The age of the recurrent group was lower than that of the non-recurrent group (P = 0.001) and the tumors without pseudocapsule were more likely to recur than those with pseudocapsule (P = 0.034). CONCLUSION: Myofibromas are characterized by heterogeneous density or signal intensity, with moderate or marked enhancement. The hypointensities and pseudocapsule on MRI may be helpful in diagnosis, and the absence of pseudocapsule and younger age may be risk factors for tumor recurrence.

Ultrasonography of Pediatric Superficial Soft Tissue Tumors and Tumor-Like Lesions.

Ultrasonography (US) is usually the first imaging examination performed to evaluate palpable or visible superficial soft tissue lesions that are common in children. Although clinical assessments, such as age at presentation, clinical course, and overlying skin discoloration, are important for the differentiation of pediatric soft tissue lesions, US allows a specific diagnosis of some typical benign lesions and helps in guiding further investigation since it provides detailed information about the lesion location, characterization including solid versus cystic, vascularity, and compressibility. Therefore, sufficient knowledge of the normal anatomy, proper ultrasonographic techniques, and the imaging findings of common and uncommon soft tissue lesions in children are crucial for accurate assessment and management of patients. In this article, we review the techniques and imaging findings focusing on the ultrasonographic features of a variety of superficial soft tissue lesions detected in children.

Massive infantile myofibromatosis of the upper lip causing airway distress in a newborn.

Infantile myofibromatosis is a rare condition characterized by benign spindle cell tumors most commonly involving the head, neck, and chest. An infant female with a prenatal diagnosis of a large facial mass was delivered via Cesarean at 34 weeks. Sparse prenatal care was received. Following delivery, the neonate was found to have an 8 cm ulcerative mass involving the upper lip and philtrum. Respiratory distress developed, and mask ventilation was difficult secondary to the size of the mass. The patient was successfully intubated after numerous attempts and then transferred to the children's hospital. Additional imaging demonstrated similar masses within bilateral iliopsoas and gluteal muscles, and her right gastrocnemius. A biopsy confirmed infantile myofibromatosis. At two weeks of life, she underwent resection with bilateral myocutaneous advancement flaps and successful extubation. She received adjuvant vinblastine and methotrexate for her pelvic and extremity disease with excellent response. We present the first case of airway distress secondary to myocutaneous myofibromatosis.

Utility of 18F-FDG PET/CT in Infantile Myofibromatosis.

Infantile myofibromatosis, a rare, nonmalignant disease seen almost exclusively in the pediatric population, can involve skin, muscle, soft tissues, bone, or viscera in either solitary or multicentric pattern. Although nonmalignant, visceral involvement in infantile myofibromatosis is a key prognostic indicator, which is associated with mortality in 75% of patients. Those with pulmonary involvement have a particularly poor outcome. This case illustrates the diagnostic utility of F-FDG PET/CT in defining disease extent in this unusual entity and compares it to other commonly used imaging modalities.

Infantile Myofibromatosis With Intracranial Extradural Involvement and PDGFRB Mutation: A Case Report and Review of the Literature.

Infantile myofibroma is a rare benign mesenchymal tumor that presents as solitary or multiple lesions (myofibromatosis) in the skin, soft tissue, bone, or internal organs. It most commonly affects the head and neck of infants and young children, but it can also affect adults. Intracranial involvement is reported to be extremely rare, and its clinical picture has been poorly characterized. Recently, it has been demonstrated that germline and somatic mutations in the platelet-derived growth factor receptor beta (PDGFRB) are associated with familial infantile myofibromatosis. We report a case of infantile myofibromatosis with predominant posterior fossa extradural involvement in a 14-year-old adolescent girl with a confirmed mutation in the PDGFRB gene.

Ruptured Infantile Myofibroma of the Head Presenting in a Neonate: Case Report and Review of the Literature.

BACKGROUND: Infantile myofibroma/myofibromatosis (IM/M) is a myofibroblastic proliferative disorder often seen in infants and children. IM/M can result in congenital tumors of the head and neck and may occasionally present to the neurosurgeon. CASE DESCRIPTION: We report a case of a solitary ruptured myofibroma of the head in a newborn patient. The lesion was initially suggestive of encephalocele. We describe the presentation and management of this patient, including relevant imaging, histopathologic evaluation, and surgical technique. We subsequently review the literature of IM/M of the head and neck, highlighting the 3 forms of the condition, each requiring a distinct management strategy. CONCLUSIONS: Although this tumor rarely presents to the neurosurgeon, it may do so in the process of ruling out other more dangerous conditions. It is therefore important to consider this diagnosis in masses that occur in the head and neck of newborns.

Unusual Presentation of Infantile Myofibroma in the Deep Palm of a Child: A Case Report and Discussion of the Differential Diagnosis.

Infantile myofibroma or myofibromatosis is a myofibroblastic and fibroblastic proliferation that is most commonly reported in children younger than 2 years of age. It is a benign process composed histologically of a biphasic pattern of spindle-shaped cells surrounding a zone of less differentiated cells in a hemangiopericytoma-like pattern. We report this tumor in a unique presentation in the deep palm of a 2-year-old child without skin ulceration and with an intimate association with the median nerve. The well-circumscribed nature of the tumor facilitated complete excision with neural preservation. Final pathology was consistent with an unusual type of myofibroma or myofibromatosis. Conservative management with partial excision has been advocated for these masses because of potential surgical morbidity and its benign nature. This case report highlights the differential diagnosis of uncommon soft tissue tumors in the pediatric hand as well as the importance of a surgeon's surgical assessment in guiding treatment.

Intracranial Infantile Myofibromatosis Mimicking Malignant Brain Tumor: A Case Report and Literature Review.

BACKGROUND: Myofibroma is a fibrous tumor of infancy that sometimes affects a single patient in a multiple fashion (infantile myofibromatosis). Its intracranial involvement is extremely rare, and its clinical picture has been poorly characterized. Here we report an interesting case of myofibromatosis with an intracranial lesion that behaved like an aggressive tumor and yet demonstrated very benign pathology. CASE DESCRIPTION: A 36-year-old man had never been diagnosed with infantile myofibromatosis despite his lifelong history of multiple tumors of various diagnoses. He presented with simple partial seizure and progressive right finger paresis. A series of brain magnetic resonance imaging scans revealed a rapidly growing lesion at his left frontal convexity, which corresponded to a high uptake area on a (18)F-fluorodeoxyglucose-positron emission tomography scan, highly suspicious of malignancy. He underwent complete tumor resection and his symptoms quickly resolved postoperatively. The pathological diagnosis was myofibroma with a MIB-1 labeling index of 1%-2%. A retrospective review of his previous tumors demonstrated the same pathology, which led to the diagnosis of myofibromatosis. Follow-up magnetic resonance imaging illustrated stabilization or regression of other preexisting lesions as well as formation of a new intracranial lesion. CONCLUSIONS: The discrepancy between rapid tumor growth associated with increased uptake on metabolic imaging and benign pathologic findings with a low proliferative index is noteworthy and should be recognized in the management of an intracranial lesion in a patient with infantile myofibromatosis. Given de novo formation of a lesion in this adult patient, long-term follow-up is essential in this disease.

Exome sequencing identifies a novel homozygous variant in NDRG4 in a family with infantile myofibromatosis.

Infantile myofibromatosis (IM) is a rare disorder characterized by the development of benign tumors in the skin, muscle, bone, and viscera. The incidence is 1/150,000 live births and the disease is the most common cause of fibrous tumors in infancy. Cases which lack visceral involvement generally have a more benign course, usually with spontaneous regression of the tumors. On the other hand, the prognosis tends to be unfavorable when there is involvement of vital organs, which can lead to significant mortality. The identification of rare variants in genes that may cause IM is the first step towards the possibility of targeted treatments; however, the molecular pathogenesis of IM is poorly understood. In the present study, we report the results of exome sequence analysis of two brothers diagnosed with visceral multicentric infantile myofibromatosis, and their healthy consanguineous parents. In the two brothers we identified novel homozygous variants in NDRG4 gene (N-myc downregulated gene family member 4) and in RLTPR gene (RGD motif, leucine rich repeats, tropomodulin domain and proline-rich containing). The healthy parents were heterozygous for both variants. Consistent with the phenotype of IM, NDRG4 is a tumor-related gene; its expression has been shown to be decreased in numerous tumor types, suggesting that it might be a tumor suppressor gene. Additionally, studies have demonstrated that NDRG4 may have a role in cell survival and tumor invasion. We thus propose that this homozygous variant in NDRG4 may be the causative variant of the autosomal recessive form of IM in the studied family and that it should be investigated in other cases of autosomal recessive infantile myofibromatosis.