Radiología de las tumoraciones palpables en el paciente pediátrico. Parte 2 / Imaging palpable tumors in pediatrics: Part 2

Las tumoraciones palpables en los niños son un motivo de consulta muy habitual para el radiólogo. El origen de las lesiones es muy variado, y algunas de ellas no reciben atención en los libros clásicos de Radiología, pese a encontrarse frecuentemente.El objetivo de esta serie de 2 artículos es revisar las características clínico-radiológicas de una selección de estas entidades que consideramos importante conocer. (AU)

Palpable tumors in children are a common reason for consulting a radiologist. The origin of these lesions varies widely, and although they are common, classic radiology books do not cover some of them.This series of two articles aims to review the clinical and radiological characteristics of a selection of palpable tumors in children that radiologists need to be familiar with. (AU)

A rare case of solitary palatal myofibroma in a young pediatric patient.

Myofibroma (MF) is a benign spindle cell neoplasm rarely found in the oral cavity. It is common in males than females (2:1) and mostly seen to develop before 2 years of age with few cases reported in adults. This article reports a rare case of solitary MF of the hard palate in an 8-year-old female child; highlighting the clinical features, histopathology, differential diagnosis while emphasizing the importance of immunohistochemistry in establishing an accurate diagnosis and management of the same. The objective should be to differentiate benign versus malignant spindle cell lesions of smooth muscle, nerve tissue, fibrocytic, and histiocytic origin. Rapid growth of the lesion often raises suspicion of malignancy and may lead to misdiagnosis and inappropriate management.

Epibulbar solitary myofibroma in an elderly patient: a case report.

A 93-year-old male patient presented with abrupt expansion of an old epibulbar mass at the temporal area of the left eye. He had a medical history of previously treated laryngeal cancer with surgery and radiotherapy. The tumor, despite being firmly attached to the underlying sclera, was excised completely and histopathological examinations revealed a solitary myofibroma. The patient had a 4-month uneventful follow-up with excellent wound healing. Solitary myofibroma may be a differential diagnosis for epibulbar masses in elderly patients.

Intraosseous solitary myofibroma of the orbit in an adolescent woman.

A 16-year-old woman presented with a painless, progressive, hard swelling in the left inferolateral orbital wall for the past 1 year. There was no diminution of vision or limitation of ocular motility. Imaging revealed an intraosseous, well-defined, expansile, soft tissue lesion in the inferolateral wall of the left orbit. A left anterior orbitotomy with complete surgical excision was performed. Histopathological evaluation of the specimen revealed fascicular pattern of spindle cells with a rich network of slit-like, branching blood vessels. Tumour cells exhibited smooth muscle actin and vimentin positivity but were negative for CD-34 and STAT-6. In absence of any systemic manifestation, a diagnosis of intraosseous solitary orbital myofibroma was made. The case highlights the importance of integrating clinical, radiological and histopathological features in overcoming the diagnostic challenge of differentiating myofibroma from other mesenchymal neoplasms. It also brings forth the importance of complete resection and curettage to prevent recurrence.

Oral myofibroma presenting as an aggressive gingival lesion.

Myofibromas are benign neoplasms of myofibroblastic origin and rarely encountered in the oral cavity. Myofibroma may frequently grow rapidly leading to suspicion of malignancy. This may lead to a tendency for aggressive management. The histopathology of this tumour has similarity with other spindle cell tumours and often requires immunohistochemical staining for diagnosis. Here, we present a case of myofibroma in a 15-year-old female patient who reported with an aggressive gingival swelling and discuss the various histopathological differential diagnosis.

Genetic variant of SRF-rearranged myofibroma with a misleading nuclear expression of STAT6 and STAT6 involvement as 3' fusion partner.

Pediatric neoplasms with a myofibroblastic differentiation are frequent in children, in particular myofibroma. Recently, a novel deep soft tissue myofibroblastic neoplasm has been described with high cellularity, a smooth muscle phenotype and SRF-RELA fusion. We report the case of a 15-year-old boy who presented with a tumor of the deep soft tissue of the arm, with overlapping histological features with the recently described SRF-RELA group of myofibromas but differing by the presence of calcifications, a novel SRF-STAT6 fusion transcript and nuclear expression of STAT6. No local recurrence nor distant metastasis was detected at the current follow-up of 29 months. The clinical relevance of this novel fusion requires further investigations.

Infantile Myofibroma: Case Report and Review of the Literature.

We report a case of solitary infantile myofibroma (IM) with partially CD34-positive neoplastic cells on the back of a newborn boy. Ultrasonography showed a multilocular mass with a hypoechoic center surrounded by an isoechoic rim. Histopathological analysis revealed that the lesion was composed of small, round cells that were tightly packed and uniform. The cells had oval nuclei and were pale, CD34-positive, and richly cellular. They had interlacing fascicles of spindle cells with features of myofibroblasts with α-smooth muscle actin positivity. We speculate that neoplastic cells in most IMs differentiate towards myofibroblasts. However, in rare cases, their differentiation is more primitive and they express CD34, with or without α-smooth muscle actin expression.

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.

Solitary intramuscular myofibroma in an adult: Case report and MR imaging findings.

Myofibroma is a benign, soft tissue neoplasm that predominantly affects infants and young children. Most occur in the skin or subcutaneous tissues, with a predilection for the head and neck regions. We describe the magnetic resonance (MR) imaging and histophathologic findings of a rare case of intramuscular myofibroma of the right deltoid in a healthy 30-year-old male. MR imaging revealed a well-circumscribed intramuscular mass, with isointense signal on T1-weighted images, hyperintense signal on T2-weighed images, and a "target-sign" with peripheral rim enhancement after gadolinium administration. The lesion was surgically excised with no complications, and the histopathologic analysis revealed the typical morphologic and histochemical markers of a myofibroma. We conclude that, although rare, myofibroma can be considered in the differential diagnosis of adults with lesions the above signal characteristics.

Solitary intraosseous myofibroma of the ilium in an adult patient: A case report and literature review.

BACKGROUND: Myofibroma is a rare benign tumor typically occurring in the skin and subcutaneous tissues of the head and neck in infants and young children. The incidence of solitary intraosseous and adult myofibroma is extremely low. Although there have been a few reported cases of solitary intraosseous myofibroma in adult patients, most of these cases involved the craniofacial bones. METHODS: We present the case of a 64-years-old woman presenting with minimal pain of the right buttock and groin. RESULT: Radiographs and computed tomography showed a huge tumor spreading around the ilium, and non-uniform calcifications were noted inside the tumor. Iliac tumor biopsy was conducted, and intraosseous myofibroma was suspected. We performed surgical resection of the mass, and a final diagnosis of myofibroma with metaplastic bone production was made. CONCLUSION: We have presented an extremely rare case of solitary intraosseous myofibroma in an adult patient.

Extended Endonasal Endoscopic Complete Resection of a Solitary Intraorbital Myofibroma: A Case Report and Literature Review.

BACKGROUND: Infantile myofibromatosis is a rare benign disease of mesenchymal origin. It occurs mostly in infants but can occur in children and adults. It presents in 2 forms: solitary and multicentric. The presence of an orbital component, whether as a solitary lesion or as part of the multicentric disease, is even rarer. Surgery is required when these tumors behave aggressively and grow rapidly or when they are large enough to cause compression symptoms. Several surgical approaches have been described to resect such lesions. CASE DESCRIPTION: We present a case of a solitary intraorbital myofibroma extending into the optic canal in a 6-year-old girl that was completely resected via an extended endonasal endoscopic approach. CONCLUSIONS: This case report highlights the advantages of the extended endonasal endoscopic approach in terms of intraoperative and postoperative factors.

Gene fusion involving the insulin-like growth factor 1 receptor in an ALK-negative inflammatory myofibroblastic tumour.

AIMS: Inflammatory myofibroblastic tumour (IMT) is a soft tissue tumour primarily affecting children and young adults. Approximately 50% of IMTs have gene fusions involving the receptor tyrosine kinase (RTK)-encoding ALK gene, providing a molecular rationale for treating IMT patients with unresectable tumours with tyrosine kinase inhibitors (TKI). However, a subset of IMT instead displays fusions affecting other RTKencoding genes, so far including NTRK3, PDGFRB and ROS1. Also, IMTs with variant RTK fusions may respond well to TKI treatment, but can be dif?cult to identify as they are negative for ALK staining at immunohistochemistry, the standard method for detection of ALK rearrangements. MATERIALS AND METHODS: We used RNA-sequencing to search for alternate fusion events in an ALK-negative IMT. RESULTS AND CONCLUSIONS: We found a novel fusion gene - FN1-IGF1R. The FN1 gene, encoding ?bronectin, is thought to provide a strong promoter activity for the kinase domain of the RTK insulin-like growth factor 1 receptor, a mechanism similar to previously described RTK fusions in IMT.

[Inflammatory Pulmonary Myofibroblast Tumor Suspected of Pulmonary Metastasis of the Lung Cancer;Report of a Case].

Inflammatory myofibroblastic tumor (IMT) of the lung is a rare disease. The patient underwent the chemoradiotherapy for primary left lung cancer which showed complete responce (CR) by the treatment. A different nodule of 10 mm in diameter was found in the left lung by computed tomography (CT). Positron emission tomography(PET) showed positive detection correspond to the nodule ( SUVmax 4.82). A partial lung resection was carried out, and the tumor was diagnosed as IMT pathologically.

Myopericytoma of the tongue base: A case report / Miopericitoma de la base lingual: presentación de un caso clínico

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The Clinical and Radiological Characteristics of Inflammatory Myofibroblastic Tumor Occurring at Unusual Sites.

Inflammatory myofibroblastic tumor (IMT) can occur rarely in the soft tissue or joint of the limb. We retrospectively collected IMT cases of these rare sites and analyzed their clinical and imaging appearance. Thirteen cases of IMT were clinically diagnosed and underwent surgical procedures, pathological analyses, and postsurgical follow-up in our two hospitals. Other than one case of IMT of the bladder wall that presented with gross hematuria, none presented with local swelling, fever, or weakness. All the cases of IMT occurring at the bone showed destruction and parosteal soft tissue masses. The boundaries between the mass and normal bone were vague, without calcifications or any periosteal reaction. Five cases of IMF showed continuous enhancement on CT; seven cases demonstrated iso- or hyposignal intensity on T1WI; one case showed hypersignal intensity on T1WI, and eight cases demonstrated a hypersignal intensity signal on T2WI. All the masses located in soft tissues showed clear and sharp boundaries with different sizes of the swelling regions surrounding muscle interspaces. Three cases showed homogeneous enhancement, one case demonstrated heterogeneous enhancement, and two cases showed edge enhancement on enhanced MRI scans. On pathology, all the lesions showed an absence of a pseudocapsule, and four cases of ALK were positive. The radiological manifestations of IMT located at the soft tissue and bones were similar to benign tumors in shape; however, peritumoral edema, parosteal soft tissue, and the invasive rim of IMT are similar to the features of malignant tumors. Different radiological methods should be used to obtain an accurate diagnosis.