Fibroepithelial Lesion Spectrum: A Case Report Documenting a Possible Transformation to a Malignant Phyllodes Tumor.

We discuss the radiological-pathological aspects of a rare case of transformation of a presumed fibroadenoma (FA) to a malignant phyllodes tumor (PT) and review the literature. Phyllodes tumors often show heterogeneous histologic features with some areas indistinguishable on core needle biopsy. A core biopsy is often a small representation of a larger lesion. As such, a complete excisional biopsy is often needed for a definitive pathologic diagnosis. Careful clinical and imaging correlation and follow-up are necessary, even in a benign fibroepithelial lesion (FEL).

Giant mucocele secondary to cocaine abuse.

Mucoceles are benign lesions originating in the paranasal sinuses. Presented here is a novel case of a giant frontoethmoidal mucocele extending into the orbit and causing proptosis. The etiology was chronic transnasal cocaine abuse leading to extensive scarring and distortion of the nasal anatomy.

Graft maturity of the reconstructed anterior cruciate ligament 6 months postoperatively: a magnetic resonance imaging evaluation of quadriceps tendon with bone block and hamstring tendon autografts.

PURPOSE: The purpose of this study was to report the potential differences associated with graft maturity measured on magnetic resonance imaging (MRI) between quadriceps tendon with bone block and hamstring tendon autografts 6 months after ACL reconstruction. METHODS: Twenty-six patients (15 male, 11 female; mean age 29.4 ± 17 years, range 13-46 years) who had undergone anatomic SB ACL reconstruction with either hamstring or quadriceps tendon with bone block autografts and had postoperative MRI 6 months after surgery. In 12 cases, the quadriceps tendon with bone block was used and hamstring in 14 cases. The signal/noise quotient was calculated to compare the difference between quadriceps tendon with bone block and hamstring autografts. RESULTS: Mean signal/noise quotient is lesser in quadriceps tendon with bone block (1.74 ± 0.39) compared with HS (2.44 ± 0.61) autografts (p = 0.020). For hamstring autograft, the distal region showed a significantly lower mean signal/noise quotient value compared with middle region, and the mean signal/noise quotient value in proximal region was the highest (distal vs middle p < 0.001; middle vs proximal p = 0.007; proximal vs distal p < 0.001). The mean signal/noise quotient of proximal region in quadriceps tendon with bone block autograft was lesser than that in hamstring. The middle region of the quadriceps tendon with bone block graft demonstrated the greatest signal/noise quotient [distal vs middle p = 0.001; middle vs proximal p = 0.027; proximal vs distal (n.s.)]. CONCLUSION: The maturity of quadriceps tendon with bone block was better in comparison with hamstring 6 months after anatomic SB ACL reconstruction. This study is clinically relevant in that modifying the individual rehabilitation according to the extent of graft maturity may be necessary to optimize patient function and prevent re-injury of the ACL graft.

Comparison of Insall-Salvati ratios in children with an acute anterior cruciate ligament tear and a matched control population.

OBJECTIVE: An anterior cruciate ligament (ACL) injury is an increasingly recognized cause of knee pain in young patients and in athletes in particular and can be detected non-invasively with MRI. Anecdotal information suggests that patella alta may be more common in the setting of this injury, but no study has documented this phenomenon. This study sought to test whether an ACL tear is associated with an increased Insall-Salvati ratio suggestive of patella alta. MATERIALS AND METHODS: Measurements of patellar height, patellar tendon length, and the Insall-Salvati ratio obtained from MRI of the knee were compared for 34 children with an arthroscopically proven ACL tear (mean age ± SD, 12.4 ± 1.4 years) and 36 control subjects with normal knee examinations (12.8 ± 2.1 years); these measurements were performed independently by two observers. RESULTS: Patellar tendon length (47.6 ± 6.6 mm vs 40.4 ± 5.7 mm) and patellar position calculated as the Insall-Salvati ratio (1.16 ± 0.16 vs 0.99 ± 0.14) were significantly greater in the knees with an ACL injury than in those without an internal injury, respectively, on MRI (p < 0.001). Patella length was not significantly different between the two groups (patients vs control subjects, 41.1 ± 4.2 mm vs 40.6 ± 2.7 mm, respectively; p = 0.523). There was good to excellent interobserver and intraobserver correlation for all measurements. CONCLUSION: There is a significant association between an ACL tear and increased patellar tendon length with a greater Insall-Salvati ratio. The mechanism for this finding is unclear, but this association provides support to suggest relative patella alta may be a risk factor for ACL injuries in pediatric patients.

Evaluation of Contrast Extravasation as a Diagnostic Criterion in the Evaluation of Arthroscopically Proven HAGL/pHAGL Lesions.

Purpose. The validity of preoperative MRI in diagnosing HAGL lesions is debated. Various investigations have produced mixed results with regard to the utility of MRI. The purpose of this investigation is to apply a novel method of diagnosing HAGL/pHAGL lesions by looking at contrast extravasation and to evaluate the reliability of such extravasation of contrast into an extra-articular space as a sign of HAGL/pHAGL lesion. Methods. We utilized specific criteria to define contrast extravasation. We evaluated these criteria in 12 patients with arthroscopically proven HAGL/pHAGL lesion. We also evaluated these criteria in a control group. Results. Contrast extravasation occurred in over 83% of arthroscopically positive cases. Contrast extravasation as a diagnostic criterion in the evaluation of HAGL/pHAGL lesions demonstrated a high interobserver degree of agreement. Conclusions. In conclusion, extra-articular contrast extravasation may serve as a valid and reliable sign of HAGL and pHAGL lesions, provided stringent criteria are maintained to assure that the contrast lies in an extra-articular location. In cases where extravasation is not present, the "J" sign, though nonspecific, may be the only evidence of subtle HAGL and pHAGL lesions. Level of Evidence. Level IV, Retrospective Case-Control series.

Lymphatic filariasis disseminating to the upper extremity.

Lymphatic filariasis is the most common cause of acquired lymphedema worldwide (Szuba and Rockson, 1998). It is endemic to tropical and subtropical regions, and its effects are devastating. With over 100 million infected persons, it ranks second only to leprosy as the leading cause of permanent and long-term disability. Wuchereria bancrofti is the etiologic agent in 90% of cases. There is a dearth of published MRI findings with pathologically proven active infections, making this entity even more of a diagnostic dilemma. Imaging may provide the first clue that one is dealing with a parasite and may facilitate proper treatment and containment of this disease. This is the first report of pathologic correlation with MRI findings in the extremity in active filariasis. The magnetic resonance images demonstrate an enhancing, infiltrative, mass-like appearance with partial encasement of vasculature that has not been previously described in filariasis. Low signal strands in T2-hyperintense dilated lymphatic channels are seen and may depict live adult worms. We hypothesize that the low signal strands correspond to the collagen rich acellular cuticle. This, in combination with the surrounding hyperintense T2 signal, corresponding to a dilated lymphatic channel, may provide more specific MRI findings for active nematodal infection, which can prompt early biopsy, pathological correlation, and diagnosis.

Prevalence of idiopathic cuneate gyrus herniation based on emergency room CT examinations.

Idiopathic brain herniation caused by a focal dural defect can be confused for a mass or post-traumatic herniation. The prevalence of idiopathic brain herniation has never been described. We sought to ascertain the prevalence of idiopathic cuneate gyrus herniation in a general emergency room (ER) population on computed tomography (CT) imaging. The purpose of this study is to elucidate cuneate gyrus herniation and differentiate it from other pathologic conditions such as mass or traumatic herniation and to provide its anatomical prevalence in an ER population. Consecutive emergency room CT scans of the brain were evaluated prospectively for cuneate gyrus herniation over a 1 year period by a neuroradiologist. Of 1,500 brain CT scans evaluated, 11 patients demonstrated idiopathic cuneus gyrus herniation. The prevalence was 0.73 %. CT manifestations are normal brain tissue herniating into the superior cerebellar cistern. Idiopathic brain herniation can be mistaken for a pathologic process. We found the prevalence of one such idiopathic brain herniation, involving the cuneus gyrus, to be exceedingly rare. CT imaging demonstrates normal brain tissue herniating beyond the dural boundary.

Passive Posterior Tibial Subluxation on Routine Knee MRI as a Secondary Sign of PCL Tear.

The posterior drawer test is an accurate clinical test to diagnose posterior cruciate ligament (PCL), indicating laxity of the PCL that allows posterior tibial translation. This study aimed to determine whether posterior tibial translation relative to the femur on routine MRI could serve as an additional sign of PCL tear. Routine knee MRI in eleven patients (7 males, 4 females) with arthroscopically confirmed isolated PCL tears were reviewed independently by two musculoskeletal radiologists. Measurements of tibial translation were made in the medial and lateral compartments of patients and controls (10 males, 12 females) without clinical or MRI evidence of ligament injury. Significant medial compartment posterior tibial translation was present in patients with PCL tear compared to controls (+2.93 mm versus +0.03 mm, P = 0.002) with excellent interobserver agreement (intraclass correlation coefficient (ICC) = 0.94). No significant difference in lateral compartment tibial translation was observed (+0.17 mm versus -0.57 mm, P = 0.366) despite excellent interobserver agreement (ICC = 0.96). Posterior tibial translation in the midmedial compartment may be a secondary sign of isolated PCL tear on routine knee MRI with passive extension without manipulation or weight bearing. Additional work in a larger cohort may better address the accuracy of this finding.

The cyamella, a lost sesamoid: Normal variant or posterolateral corner anomaly?

Cyamella, an accessory sesamoid ossicle of the popliteus in the region of the proximal myotendinous junction, is an extremely unusual finding, with a paucity of current published literature describing its MR appearance. In this case study, we describe MRI findings in a 44-year-old female presenting with pain after a stretching workout. Bone edema in the cyamella, edema in the myotendinous portion of the popliteus, and pericapsular edema at the posterolateral corner were identified. While commonly seen in certain mammalian species, cyamella is rare in humans. The upright walking posture of humans requires posterolateral corner structures to play a greater role in structural support and weight-bearing. We hypothesize that the cyamella, while intrinsic to certain mammalian species, may interfere with these biomechanical functions in upright walking posture, thereby predisposing to isolated injury of the posterolateral corner in humans.

Nature abhors a vacuum: bilateral prominent rotator cable in bilateral congenital absence of the long head of the biceps tendon.

Bilateral agenesis of the long head of the biceps tendon is an exceedingly rare anomaly and can be a challenging diagnostic dilemma whose differential diagnosis includes tear. We present the third case of bilateral agenesis of the long head of the biceps tendon. Absent or shallow intertubercular sulcus is a constant finding and serves to differentiate this entity from tear. Our case is unique in that there was a radial ray anomaly, where prior reports of bilaterality did not demonstrate associated congenital anomalies. We also describe the newly reported finding of thickening of the rotator cable without the presence of rotator cuff tear. Thickening of the rotator cable may be an associated finding with agenesis of the biceps tendon.

Fibrolipomatous hamartoma of the median nerve on CT.

Fibrolipomatous hamartomas are rare lesions with a pathognomonic appearance on MRI. I describe CT findings that parallel the pathognomonic description on MRI. While these lesions are typically evaluated on MRI, they may be discovered incidentally on a CT scan of the upper extremity. In addition, contraindications to MRI may require CT evaluation in some cases. The findings of soft tissue with components of isointense fatty signal splaying out the nerve fascicles described as pathognomonic on MRI may also be applied on CT. While there is no surgical pathology of the lesion in this case, these lesions are not typically treated surgically. The pathognomonic findings on MRI can also be reproduced reliably on CT. Knowledge of these findings on CT can prevent unnecessary biopsy.

Cervical carotid artery dissection: current review of diagnosis and treatment.

Carotid artery dissection is a cause of stroke, especially in young and middle-aged patients. A dissection occurs when there is an intimal tear or rupture of the vasa vasorum, leading to an intramural hematoma, which is thought to result from trauma or can occur spontaneously, and is likely multifactorial, involving environmental and intrinsic factors. The clinical diagnosis of carotid artery dissection can be challenging, with common presentations including pain, partial Horner syndrome, cranial nerve palsies, or cerebral ischemia. With the use of noninvasive imaging, including magnetic resonance and computed tomography angiography, the diagnosis of carotid dissection has increased in frequency. Treatment options include thrombolysis, antiplatelet or anticoagulation therapy, endovascular or surgical interventions. The choice of appropriate therapy remains controversial as most carotid dissections heal on their own and there are no randomized trials to compare treatment options.

MRI Appearance of Nerve Regeneration in a Surgically Repaired Ulnar Nerve.

BACKGROUND AND PURPOSE: Magnetic resonance imaging (MRI) findings for surgical repair of a transected nerve have not been published. We describe the first reported postoperative MR imaging findings of a repaired transected ulnar nerve. METHODS: A patient presented to our institution following surgical repair of a severed ulnar nerve at the level of the forearm. MRI was obtained to evaluate postsurgical outcome and potential complications. RESULTS: Magnetic resonance imaging demonstrates the presence of nerve fascicles that are clearly depicted above and below the level of injury but appear indistinct at the level of transection. CONCLUSION: To our knowledge, the MRI appearance of a repaired transected nerve has not been previously described. We believe that the MRI findings may be used to assess the anatomic progress of nerve healing and, when combined with a series of progressively favorable results from a focused neurologic exam, provide convincing evidence of nerve regeneration.

Complex carpal malformation without a cause.

Carpal dislocation is an uncommon event. We present a 4-year-old male child who had the clinical appearance of a Madelung's deformity; however, he failed to fulfill the radiological criteria for a Madelung's deformity. The carpal bones had not yet ossified making it difficult to arrive at a diagnosis using radiograph alone. Magnetic resonance imaging was diagnostic because of the ability to delineate the carpal cartilaginous ossification centers. Chronic wrist dislocation should be considered in the differential diagnosis of a long-standing wrist deformity that clinically resembles a Madelung's deformity in a young child.

Comparison of endovascular versus open repair of abdominal aortic aneurysms: a review.

The purpose of this review is to highlight the indications, complications, and outcomes observed with endovascular or open repair for abdominal aortic aneurysms. We selected literature published during 2005 to 2008, encompassing a research period from 1987 to 2005 which compared these 2 techniques and followed various outcomes of morbidity and mortality.

Three cases of benign giant cell tumor with unusual imaging features.

OBJECTIVE: Imaging findings for giant cell tumors (GCT) of the spine displaying aggressive characteristics have not been widely reported. MATERIALS AND METHODS: Patients with biopsy-proven GCT were included in the study. Three cases fulfilled these criteria. RESULTS: MRI and CT demonstrated disc space involvement and vertebral body compression. CONCLUSION: Acute fracture, subluxation, and extension through the disc space have not been previously described and, while atypical for benign lesions, may in fact be typical for GCT of the spine.

Conventional intramedullary chondrosarcoma with subarticular involvement.

A 78-year-old female patient with a lesion in the distal tibia is shown to have conventional intramedullary chondrosarcoma. Typical considerations for this end-of-bone neoplastic lesion are giant cell tumor, clear cell chondrosarcoma, and chondroblastoma. Salient clinical and radiographic features and behavior of this lesion broaden the typical view of conventional intramedullary chondrosarcoma.

The tibial sulcus as a reference point for total knee arthroplasty.

Determining the amount of tibial resection is an important aspect of knee arthroplasty. The tibial sulcus is a reference point that should be unaffected by degenerative processes. This study compared the tibial sulcus and plateau height for 50 arthritic knees to 50 normal knees on magnetic resonance imaging. The tibial sulcus measured 17.09 mm in arthritic knees and 17.88 mm in normal knees. Sulcus height differences were not statistically significant. Based on these findings, a tibial cut 12 to 14 mm from the sulcus is recommended as a reference point in arthritic knees. This measuring technique has application in limited incision knee arthroplasty.

MRI findings of rhabdomyolysis from streptococcal pharyngitis.

Rhabdomyolysis has been described as a rare sequela of severe infections by group A streptococcus related to toxic shock syndrome in adults. Streptococcal pharyngitis, on the other hand, has never been reported to cause rhabdomyolysis. We report a case of rhabdomyolysis in a child after an uncomplicated course of group A streptococcal pharyngitis. Although MRI of rhabdomyolysis from other causes has been described in a few case reports, this is a unique MRI description of its occurrence with streptococcal pharyngitis.