Aggressive infantile fibromatosis. Pulmonary metastases documented by plain film and computed tomography

Aggressive infantile fibromatosis, one of the juvenile fibromatoses, is generally considered a benign lesion, but it does tend to recur locally because of its invasive nature. Distant metastases are considered rare. This case report documents pulmonary metastases arising 2 years after resection of the primary lesion from the thigh of an infant. This is the seventh reported case of distant metastasis from aggressive infantile fibromatosis. Computed tomography of the original lesion as well as the metastases are presented.     

Infantile fibromatosis in childhood: findings on MR imaging and pathologic correlation

AIM: The objective of this study was to analyse the MR imaging findings of infantile fibromatosis of childhood and to correlate them with histopathological features. MATERIALS AND METHODS: Seven patients with histologically proven infantile fibromatosis were included in this study. The findings on MR images were retrospectively evaluated and then correlated with the pathological features. Findings on MR imaging evaluated included signal intensity, extent of hyperintense area on T2-weighted images, margins of the lesion, the degree and pattern of enhancement and the presence of fatty tissue. Pathological features evaluated included cellularity, collagenization, and myxoid change. A five point scale was used for the evaluation of the extent of hyperintense area on MR imaging, and each of pathological features. RESULTS: On T1-weighted images, the lesions were iso-intense in two patients; iso- and hypointense in three; and iso-, hypo- and hyperintense in two. On T2-weighted images, iso-, hypo- and hyperintense areas were mixed in all patients, the hyperintense area being the largest portion of the lesion. The margins of the lesions were infiltrative in four patients (57%), smooth in two (29%) and mixed in one (14%). Enhancement was marked in five patients (72%) and diffuse in five (71%). Regardless of the hyperintense signal intensity on T2-weighted images, the grades of each pathologic feature were variable. CONCLUSION: Infantile fibromatosis on MR imaging causes an enhancing mass, that is largely hyperintense on T2-weighted images. Areas of high signal intensity on T2-weighted images corresponded to variable grades of cellularity, collagenization, or myxoid change.     

Juvenile ossifying fibroma: CT and MR findings

We describe the CT findings in four patients and the MR imaging in one patient with juvenile ossifying fibroma. Three lesions involved the maxillary sinus and extended to the surrounding structures; one lesion was confined to the maxillary bone. CT scan revealed well-defined, expansile lesions with variable amount of calcifications. On MRI one lesion had intermediate signal intensity with significant contrast enhancement.     

MR imaging in fibromatosis: results in 26 patients with pathologic correlation

Fibromatoses are a diverse group of soft-tissue lesions that have been inconsistently categorized and treated. The purpose of our study was to establish the range of appearances of fibromatoses on MR images and perform a pathologic correlation to explain the variable signal-intensity patterns. During a 3-year period, 26 patients with deep fibromatoses were examined with MR. The MR images were evaluated for signal-intensity characteristics, and findings were correlated retrospectively with the pathologic diagnoses. The results showed that the MR appearance of fibromatoses is similar to that of other soft-tissue lesions, and the signal intensities vary greatly from lesion to lesion and within lesions themselves. The fibromatoses were either hyperintense, isointense, hypointense, or of mixed signal intensity relative to adjacent skeletal muscle. The hypointense areas appear to be zones of hypocellularity and dense collagen deposition. Microscopically all of the lesions invaded adjacent structures, but the MR appearances of the margins varied and were judged to be well demarcated (n = 14), intermediate (n = 5), or poorly demarcated (n = 6). Our experience shows that fibromatoses have a variable MR appearance no different from that of other soft-tissue lesions, and this variability reflects the composition and cellularity of the lesions.     

Osseous metastasis from renal cell carcinoma: "flow-void" sign at MR imaging

PURPOSE: To characterize the appearance and determine the importance of the "flow-void" sign on magnetic resonance (MR) images of patients with osseous metastasis from renal cell carcinoma. MATERIALS AND METHODS: Three musculoskeletal radiologists retrospectively and independently reviewed the medical records of 16 patients who had undergone MR imaging and in whom 20 osseous metastatic lesions from renal cell carcinoma had been diagnosed on the basis of clinical and radiologic findings. They assessed the MR images for the presence and frequency of the flow-void sign--multiple dot-like or tubular structures with low signal intensity. They then compared these findings on MR images with the corresponding areas on available images obtained with radiography (n = 16), computed tomography (CT) (n = 6), and digital subtraction angiography (n = 3) and with the results of histopathologic analysis for the same patient group. They noted the location, diameter, and appearance of the lesion and the flow-void sign, as well as variations in signal intensity within the lesion and among lesions. Statistical analysis was performed to determine the level of interobserver agreement. RESULTS: Radiographic findings and the level of signal intensity on MR images were nonspecific for diagnosis of osseous metastasis from renal cell carcinoma. The flow-void sign was identified at the lesion core or margin with a mean frequency of 76.7% by the three observers (in 15, 16, and 15 of 20 lesions, by observers 1, 2, and 3, respectively). Most of these areas of low signal intensity were tubular structures of less than 3 mm in diameter; in three lesions, they measured 5-8 mm in diameter. In 14 lesions, these structures corresponded to dilated blood vessels or veins identifiable on CT images (six lesions) or digital subtraction angiographic images (four lesions) or at histopathologic analysis (four lesions). The flow-void sign on MR images corresponded to vessels depicted on the CT scans available for six lesions and on the angiographic images available for four lesions. CONCLUSION: Observation of the flow-void sign in lesions depicted on musculoskeletal MR images may prove helpful for diagnosing osseous metastasis from renal cell carcinoma and for treatment planning, especially in patients with occult or forgotten primary renal tumor.     

Nodular fasciitis in the head and neck: CT and MR imaging findings

BACKGROUND AND PURPOSE: The purpose of this study was to describe the CT and MR imaging findings of nodular fasciitis occurring in the head and neck region. METHODS: CT (n = 6) and MR (n = 4) images obtained from 7 patients (3 men and 4 women; mean age, 19.4 years; age range, 1-48 years) with surgically confirmed nodular fasciitis in the head and neck were retrospectively reviewed. All patients presented with a palpable mass in the head and neck that was noticed 1-3 months earlier: 5 in the face, one in the occipital scalp, and the remaining one in the supraclavicular fossa. We investigated the CT and MR imaging characteristics with emphasis on the location, size, internal content, margin, enhancement pattern, and signal intensity of the lesion. RESULTS: All lesions appeared as a discrete mass on imaging, ranging from 1.0 cm to 4.6 cm in diameter (mean, 2.2 cm). Six lesions, all of which appeared benign, were located in the subcutaneous tissue superficial to the deep cervical fascia. The remaining lesion was located deep to the temporalis muscle and showed an aggressive imaging appearance, markedly eroding the bony orbit and skull. Five lesions were solid, and 2 lesions were partly or completely cystic in appearance. Five lesions were well defined, whereas 2 lesions were ill defined. Four of 5 solid lesions showed moderate to marked diffuse enhancement, whereas the remaining lesion demonstrated mild enhancement. Two cystic lesions showed peripheral, nodular, or rim-like enhancement. Compared with muscle, both solid lesions had isointense signal intensity on T1-weighted images and hyperintense signal intensity on T2-weighted images, whereas the signal intensity of the solid portions of the deep-seated, partly cystic lesion was isointense on both T1-weighted and T2-weighted images. CONCLUSION: Although rare, nodular fasciitis occurs as a discrete solid or cystic mass in the head and neck, depending on the predominant stromal components. When one sees a head and neck mass with a superficial location and moderate to marked enhancement on CT and MR imaging, nodular fasciitis should be included in the differential diagnosis, especially in patients with a recently developed, rapidly growing mass and a history of recent trauma.     

侵袭性纤维瘤病的MRI诊断

目的 分析侵袭性纤维瘤病(AF)的MRI特点,提高对该病的认识和诊断水平.方法 回顾性分析66例经手术病理证实的AF( 19例原发,47例复发)的临床资料和MRI表现,并与术后病理进行对照.结果 66例患者中位年龄31岁,男女比例1∶3.4.共检出肿瘤80个.浅表纤维瘤病5个;深部纤维瘤病75个,其中发生于腹内2个,腹壁6个,腹壁外67个.肿瘤长径平均大小为(8.7±5.4)cm,浅表肿瘤长径为(5.7±2.8)cm,深部肿瘤长径为(8.9±5.5)cm.98.8％( 79/80)表现为肌肉内占位病变;58.8％ (47/80)肿瘤呈卵圆形或分叶状,27.5％(22/80)呈不规则浸润状;60％(48/80)病灶边界清晰,其中4个可见假包膜.大部分肿瘤与肌肉相比在T1WI呈等、稍高或稍低信号,T2WI呈不均匀高信号,增强后可见明显不均匀强化.所有患者均未见囊变坏死和瘤周水肿.2个肿瘤见邻近骨质破坏.结论 侵袭性纤维瘤病在MRI上具有一定特征性,MRI对该病的诊断、肿瘤侵犯范围及其与周围结构关系的评估有重要价值.     

Calcifying Aponeurotic Fibroma: Case Report with Radiographic and MR Features

Calcifying aponeurotic fibroma is a rare, benign fibroblastic tumor. The lesion has a propensity for local invasion and a high recurrent rate. Therefore, accurate preoperative diagnosis and complete excision are important to prevent the recurrence of the tumor after surgical removal. However, radiographic and magnetic resonance imaging findings of calcifying aponeurotic fibroma have been extremely rarely described in the radiology literature. Thus, we report a rare case of calcifying aponeurotic fibroma affecting the dorsal wrist in a 67-year-old man, describe radiographic and MR findings, and discuss the differential diagnosis of the tumor.     

Eosinophilic granuloma: MRI manifestations

The appearance on magnetic resonance imaging (MRI) of 16 cases of pathologically proven eosinophilic granuloma were reviewed retrospectively and correlated with the radiographic appearance of the lesion. The most common MR appearance (ten cases) was a focal lesion, surrounded by an extensive, ill-defined bone marrow and soft tissue reaction with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, considered to represent bone marrow and soft tissue edema (the flare phenomenon). The MRI manifestations of eosinophilic granuloma, especially during the early stages, are nonspecific, and may simulate an aggressive lesion such as osteomyelitis or Ewings sarcoma, or other benign bone tumors such as osteoid osteoma or chrondroblastoma.     

Misleading aggressive MR imaging appearance of some benign musculoskeletal lesions.

After plain radiography has been performed, magnetic resonance (MR) imaging is considered the modality of choice for the evaluation of suspected musculoskeletal lesions because of its exquisite sensitivity to changes in the signal intensity of marrow and soft tissue. That sensitivity, however, may lead to an overestimation of the aggressiveness and extent of some benign bone lesions, particularly in children. Such lesions include chondroblastoma, osteoid osteoma, eosinophilic granuloma, and stress fractures. Potentially misleading MR features commonly seen include prominent marrow edema, soft-tissue edema, and apparent mass effect adjacent to the bone lesion. Features that these lesions have in common that may explain the MR findings include associated inflammatory reactions caused by the lesions and their occurrence in childhood, when the periosteum is more loosely attached. Knowledge of the potential pitfalls encountered with MR imaging may help explain the discrepancy between the radiographic and MR appearances of these benign lesions and avoid misplaced reliance on MR imaging for a diagnosis. Radiography remains the single most valuable modality in determining a differential diagnosis for bone lesions.     

Pigmented villonodular synovitis: a report of MR imaging in two cases

Although magnetic resonance (MR) imaging has been used to evaluate many musculoskeletal lesions, the MR appearance of pigmented villonodular synovitis (PVNS) has not been described in detail. The authors describe two cases of PVNS in the knee imaged with both computed tomography and MR. In both cases parts of each lesion had very low signal intensity on both short repetition time (TR)/echo time (TE) sequences and long TR/TE sequences. Other portions of both lesions had intermediate signal intensity (equal to or higher than that of muscle but lower than that of fat) on short TR/TE sequences and increasing signal intensity on longer TR/TE images. In one case, the lesion also had a cystic component that showed MR changes typical of complex fluid. The authors propose that the MR signal characteristics demonstrated in these cases may be explained by the unique tissue components of the lesion, particularly hemosiderin and fat.     

Parenchymal abnormalities associated with cerebral venous sinus thrombosis: assessment with diffusion-weighted MR imaging

BACKGROUND AND PURPOSE: The common entity cerebral venous sinus thrombosis is associated with the poorly characterized imaging finding of parenchymal abnormalities; diffusion-weighted imaging has offered some insight into these manifestations. We assessed the relationship between the diffusion constant from apparent diffusion coefficient (ADC) maps in patients with cerebral venous thrombosis (CVT) with follow-up imaging findings and clinical outcome. METHODS: We evaluated the medical records and T2-weighted MR images of 13 patients with CVT complicated by intraparenchymal abnormality. Diffusion-weighted (DW) images and ADC maps were evaluated for increased, decreased, or unchanged signal intensity and were compared with signal intensity of contralateral, normal-appearing brain. In addition, ADCs were obtained in nine pixel regions of interest in abnormal regions in eight of the 13 patients. RESULTS: Eight patients had superficial CVT, and five had superficial and deep CVT. CVT of deep veins was associated with deep gray nucleus and deep white matter abnormalities, whereas superficial CVT was associated with cortical and subcortical abnormalities. Twenty-four nonhemorrhagic lesions were identified in 10 of 13 patients on the basis of follow-up imaging findings. Four patients without seizures had lesions with decreased diffusion that appeared hyperintense on follow-up T2-weighted images, three patients with seizures had lesions with decreased diffusion that resolved, and seven patients had lesions with increased diffusion that resolved. Three of 10 patients had more than one lesion type. No difference was noted in mean ADCs for lesions with decreased diffusion that resolved compared with lesions with decreased diffusion that persisted. CONCLUSION: DW imaging in these patients disclosed three lesion types: lesions with elevated diffusion that resolved, consistent with vasogenic edema; lesions with low diffusion that persisted, consistent with cytotoxic edema in patients without seizure activity; and lesions with low diffusion that resolved in patients with seizure activity. This information may be important in prospectively determining severity of irreversible injury and in patient treatment.     

Radiologic-Pathologic Correlation of Unusual Lingual Masses: Part II: Benign and Malignant Tumors

Because the tongue is superficially located and the initial manifestation of most diseases occurring there is mucosal change, lingual lesionscan be easily accessed and diagnosed without imaging analysis. Some lingual neoplasms, however, may manifest as a submucosal bulge and be located in a deep portion of the tongue, such as its base; their true characteristics and extent may be recognized only on cross-sectional images such as those obtained by CT or MRI.Some uncommon tongue neoplasms may have characteristic radiologic features, thus permitting quite specific radiologic diagnosis. Lipomas typically manifest at both CT and MR imaging as homogeneous nonenhancing lesions. Relative to subcutaneous fat they are isoattenuating on CT images, and all MR sequences show them as isointense. Due to the paramagnetic properties of melanin, metastases from melanotic melanoma usually demonstrate high signal intensity on T1-weighted MR images and low signal intensity on T2-weighted images.Although the radiologic findings for other submucosal neoplasms are nonspecific, CT and MR imaging can play an important role in the diagnostic work-up of these unusual tumors. Delineation of the extent of the tumor, and recognition and understanding of the spectrum of imaging and the pathologic features of these lesions, often help narrow the differential diagnosis.     

Infantile fibromatosis of the neck with intracranial involvement: MR and CT findings.

CT and MR imaging studies were performed in a 3-year-old boy with infantile fibromatosis arising from the infratemporal fossa and extending into the middle cranial fossa. On CT scans, the lesion was hyperattenuating (44-49 Hounsfield units [HU]), enhancing significantly after application of contrast material (63-66 HU). The MR images showed a multilobulated lesion of heterogeneous signal intensity. The tumor was markedly hypointense on T2-weighted images and slightly hypointense on T1-weighted images relative to brain tissue, iso- or slightly hyperintense relative to tongue muscle on both T2- and T1-weighted images, and enhanced strongly after administration of gadopentetate dimeglumine.     

Primary musculoskeletal tumors of fibrous origin

Tumors of fibrous origin include fibrous dysplasia (FD), fibroxanthoma (nonossifying fibroma), cortical desmoid, desmoplastic fibroma, fibrosarcoma, and malignant fibrous histiocytosis (MFH). Benign fibrous lesions (FD, fibroxanthoma, and cortical desmoid) frequently demonstrate pathognomonic radiologic characteristics obviating the need for biopsy. Indeed, biopsy of these lesions can occasionally lead to confusion with more aggressive lesions. Desmoplastic fibroma and the malignant fibrous lesions (fibrosarcoma and MFH) often reveal nonspecific imaging features of a solitary nonmineralized lesion with aggressive characteristics. However, imaging is important as with other neoplasms in delineating the extent of involvement for staging purposes. This article reviews the spectrum of clinical characteristics, pathology, imaging appearances, treatment, and prognosis of lesions of fibrous origin in bone.     

Mucocutaneous and peripheral soft-tissue hemangiomas: MR imaging

Hemangiomas are common congenital lesions that may have devastating sequelae. The extent and location of a lesion determines the therapeutic approach. We describe 11 patients with mucocutaneous or peripheral soft-tissue hemangiomas to illustrate the ability of magnetic resonance (MR) imaging to define clearly and noninvasively the extent and anatomic relationships of hemangiomas. The major advantage of MR imaging over computed tomography or angiography is the exquisite difference in contrast between hemangiomas and the surrounding structures on T2-weighted MR images, in which hemangiomas have a relatively intense signal. Hemangiomas demonstrated relatively low signal intensity (similar to muscle) on T1-weighted images, which were markedly inferior to T2-weighted images in defining the extent of the lesions. Phleboliths and feeding or draining vessels were rarely visible. The information obtained with MR imaging may be valuable clinically in planning surgical resection or laser therapy of aggressive lesions, in evaluating effectiveness of medical or embolic therapy, and in defining recurrence.     

Granular cell tumor of the extremity: magnetic resonance imaging characteristics with pathologic correlation

Objective The purpose of this study is to delineate the magnetic resonance (MR) appearance of a granular cell tumor (GrCT) of the extremity and to correlate the imaging appearance with the microscopic findings.Design and patients A retrospective review of five patients with a histopathologic diagnosis of GrCT and pre-operative MR imaging of the neoplasm was done. The images were reviewed by two musculoskeletal radiologists in a consensus fashion. Lesion location, size, shape, margination, and signal intensity characteristics were assessed. MR findings were correlated with histopathological examination.Results The benign subtype of GrCT is usually isointense or brighter than muscle on T1-weighted sequences, round or oval in shape, superficial in location, and 4 cm or less in size. On T2-weighted sequences, benign lesions may demonstrate a high peripheral signal, as well as a central signal intensity that is isointense to muscle or suppressed fat. A significant stromal component in the tumor and, hypothetically, a ribbon-like arrangement of tumor cells may influence the signal intensity demonstrated on the T1 and T2-weighted sequences. The malignant subtype may demonstrate signal intensity characteristics and invasion of adjacent structures often seen with other aggressive neoplasms; sizes larger than 4 cm and association with major nerve trunks can be seen.Conclusion Benign GrCT has imaging characteristics which may distinguish this tumor from other soft tissue neoplasms, as well as the malignant type of this tumor.     

Desmoid-type fibromatosis in the head and neck: CT and MR imaging characteristics

Introduction

In the head and neck region, desmoid-type fibromatosis is an uncommon tumor, and the imaging features have not been well described. The purpose of this study was to describe imaging features with their pathologic correlation of desmoid-type fibromatosis in this region.

Methods

Computed tomographic (CT) and magnetic resonance (MR) images of nine consecutive patients (five women and four men; age range, 2–72 years; mean age, 28 years) with desmoid-type fibromatosis in the head and neck were retrospectively evaluated, focusing on lesion location, size, shape, presence of a rim of surrounding fat, CT attenuation, signal intensity, and enhancement characteristics on MR with pathologic correlation.

Results

Desmoid-type fibromatosis involved perivertebral space (n?=?5) and carotid space (n?=?1) in six adult patients. In three pediatric patients, the fibromatosis primarily involved submandibular space (n?=?2) and masticator space (n?=?1) with frequent invasion to the adjacent spaces (3/3). A mean greatest dimension of 5.8 cm, elongated shape (7/9), and rim of surrounding fat (8/9) were the common features of the desmoid-type fibromatosis. Tumors often showed iso (3/7) or high attenuation (3/7) on postcontrast CT, high signal intensity (6/9) on T2-weighted image, iso signal intensity (8/9) on T1-weighted image, and strong MR enhancement (8/9). Characteristic nonenhancing low signal intensity bands (8/9) on all MR sequences were well correlated with dense collagenous stroma.

Conclusions

Desmoid-type fibromatosis in the head and neck of adults frequently involves perivertebral space. Along with various common imaging features, desmoid-type fibromatosis shows characteristic nonenhancing low signal intensity bands on MR images.     

Desmoplastic fibroma of bone: MRI features

Desmoplastic fibroma of bone is a very rare benign tumor, which may be locally aggressive. In contrast to the well-documented radiological appearance, the literature on MR imaging features of this tumor is scarce. The MR imaging characteristics in our case are compared to those previously reported. Although there is a considerable overlap in the MR imaging features with other bone tumors, an interesting MR feature of desmoplastic fibroma is the presence of low to intermediate signal intensity foci on T2-weighted images, which radiographically does not correspond to calcifications. This feature may help narrow the differential diagnosis. Received: 24 May 1999 Revision requested: 30 June 1999 Revision received: 8 October 1999 Accepted: 14 October 1999     

Cross-sectional imaging patterns of desmoplastic fibroma

The aim of this study was to work out the cross-sectional imaging characteristics of desmoplastic fibroma (DF). In 3 patients with histologically proven DF, the imaging characteristics obtained with cross-sectional techniques were reviewed retrospectively. Radiographs and CT scans were available in all patients, and plain and contrast-enhanced MR examinations in 2 patients. Compared with conventional radiographs, CT allowed more accurate assessment of the extent of bone destruction including cortical breakthrough and articular invasion. Intramedullary tumor growth and soft tissue extension was best detected with MRI. Apart from heterogeneity on MR images, DF displayed nonspecific low signal intensity on unenhanced T1-weighted images and an intermediate to high signal intensity including areas of low intensity on T2-weighted images. Desmoplastic fibroma showed a distinct, inhomogeneous gadolinium enhancement. Although cross-sectional imaging features of DF are nonspecific, some MR characteristics, such as inhomogeneous contrast enhancement and the presence of low-intensity regions on T2-weighted images, are helpful in determining the differential diagnosis. Cross-sectional imaging of DF is useful for local staging of the tumor because it provides valuable information about the extent of bone destruction as well as medullary and extraosseous spread.