Magnetic resonance imaging of peripheral soft tissue hemangiomas

Synovial Angioma of the FDP Flexor Sheath: A Rare Cause of Carpal Tunnel Syndrome

It has been previously noted that synovial haemangiomas in the hand and wrist are very rare pathological entities. We report the case of a 34-year-old right hand dominant male who presented to his general practitioner with an enlarging left volar wrist/ palmar mass, who further developed symptoms consistent with carpal tunnel syndrome. An MRI scan subsequently confirmed a large, complex mass with area of necrosis and peripheral enhancement. The rate of mass growth and radiological features raised the possibility of a soft tissue malignancy, and the gentleman was urgently referred to our unit for surgical exploration and removal of tumour. Surgical exploration demonstrated a tan-coloured soft tissue mass on the ulnar aspect of the median nerve. It appeared to arise from, and marginally infiltrated, the tendon sheath of the FDP tendon to the ring finger and the lumbrical muscle of the fourth ray; the distal and proximal extent of the tumour was difficult to define due to the diffuse growth of the tumour. Resection was achieved with macroscopic margins, with excellent functional recovery immediately and at 6 month follow-up. Histological analysis was consistent with a synovial haemangioma, comprising of numerous thin-walled blood vessels with a central cystic cavity containing blood and fibrin. Our case further demonstrates the diagnostic challenges posed by compressive neuropathy due to soft tissue masses, even with thorough clinical and radiological assessment. In the context of a rapidly growing tumour, malignancy must always be suspected and might highlight a role for pre-operative biopsy.

Hemangiomas of the fingers: MR imaging evaluation

PURPOSE

To report the magnetic resonance (MR) imaging features of finger hemangiomas.

MATERIALS AND METHODS

Sixteen patients clinically suspected of having hemangioma of the finger underwent 1.5-T MR imaging with a customized local gradient coil. The location, size, margins, signal intensity, and enhancement patterns of the lesions were noted. In accordance with the literature on MR imaging of deep hemangiomas, the authors' findings could be divided into those with typical features-that is, high signal intensity at T1- and T2-weighted imaging, lobulated appearance, strong enhancement, and heterogeneous pattern with flow void artifacts-and those with atypical features. The reference standard was surgery (n = 12) or clinical outcome (n = 4).

RESULTS

One posttraumatic hematoma was excluded. Most lesions were in the fingertip (n = 10), with involvement of the nail bed and/or the pulp (n = 5). Hemangiomas were classified as typical in ten cases and atypical in five. The mean size of typical lesions was larger than that of atypical lesions. The unique imaging features of atypical hemangiomas included a masslike appearance, which was either homogeneous with diffuse enhancement-suggestive of hypervascularity (n = 2)-or heterogeneous with poor enhancement (n = 3).

CONCLUSION

MR imaging characteristics of finger hemangiomas can be classified as typical or atypical. Knowledge of both patterns can be helpful in the distinction of soft-tissue abnormalities at this location.

Magnetic resonance imaging of intramuscular haemangiomas with emphasis on contrast enhancement patterns

Fifteen patients with intramuscular haemangiomas were evaluated with magnetic resonance imaging (MRI). Phleboliths were demonstrated by plain films or CT in six cases, which are characteristic for haemangioma. MRI showed intermediate or slightly high signal intensity on T1-weighted spin-echo images, and overall extremely bright signal on T2-weighted images. Twelve patients had a heterogeneous signal intensity and serpentine pattern on all sequences. A draining vessel was identified in a patient with histologically confirmed diagnosis of arteriovenous type of hemangioma. In three cases with localized small lesions, the MR appearance on T1 and T2-weighted conventional spin-echo sequences was homogenous. Two of the three showed a serpentine pattern on contrast enhanced images. In a patient with a soft tissue mass suspected of representing a haemangioma, MRI may provide more specific information, regarding the characteristics and extent of the lesion than other imaging techniques. In small localized lesions, contrast enhanced MRI may also offer significant advantage, making the identification of serpentine pattern possible which is a characteristic morphological feature of haemangioma.

MR imaging of skeletal muscle hemangiomas. A report of 16 cases

PURPOSE

Our purpose was to evaluate how MR imaging depicts the vascular fibrofatty structure of hemangiomas.

MATERIAL AND METHODS

MR images of 16 histologically proven skeletal muscle hemangiomas were reviewed retrospectively in a nonblinded manner. One patient was examined at 0.5 T, 9 at 1.0 T, and 6 at 1.5 T, and the imaging protocols varied.

RESULTS

All lesions were lobulated/tubular. Signal characteristics of fat were seen in 13 lesions as lace-like thin septa within or around the tumor. All 16 studies exhibited a hyperintense signal on T2-weighted spin-echo (SE) (n=15) or T1-weighted fast fat suppressed inversion recovery SE images (n=1). Postcontrast images showed marked signal enhancement in parts of the areas, both of high and low T2-weighted signal. Surgical staging based on MR images was correct in all lesions.

CONCLUSION

MR images display the characteristic vascular fibrofatty structure of hemangiomas and may allow correct diagnosis.

Synovial hemangioma: imaging features in eight histologically proven cases, review of the literature, and differential diagnosis

OBJECTIVE

This study was undertaken to describe the imaging characteristics of synovial hemangioma, with the goal of improving the disappointing rate (22%) of clinical diagnosis of this condition. A review of the literature and the differential diagnosis of intra-articular lesions, including synovial osteochondromatosis and pigmented villonodular synovitis, are also presented.

PATIENTS

The subjects of the study were 8 patients (4 males, 4 females; age range: 5-47 years; mean age: 19 years) with histologically confirmed synovial hemangioma involving the knee (n = 7) or wrist (n = 1). We retrospectively examined the imaging studies performed in these patients, including plain radiography (n = 8), magnetic resonance imaging (MRI; n = 4), angiography (n = 3), arthrography (n = 2), and contrast-enhanced computed tomography (CT; n = 2).

RESULTS

Plain radiographs showed a soft tissue density suggesting either joint effusion or a mass in all patients. Phleboliths and bone erosions on plain films in four patients with extra-articular soft tissue involvement pointed to the correct diagnosis. Angiography, showing fine-caliber, smooth-walled vessels, contrast pooling in dilated vascular spaces, and early visualization of venous structures, was diagnostic in two patients. Neither arthrography nor CT yielded specific enough findings. MRI was consistently effective in allowing the correct diagnosis to be made preoperatively, showing an intra-articular or juxta-articular mass of intermediate signal intensity on T1-weighted images and of high signal intensity of T2- or T2*-weighted images with low-signal channels or septa within it. A fluid-fluid level was found in two patients with a cavernous-type lesion.

CONCLUSION

Despite the limited nature of this study, it shows clearly that MRI is the procedure of choice whenever an intra-articular vascular lesion such as synovial hemangioma is suspected. Nonetheless, phleboliths and evidence of extra-articular extension of plain radiographs point to angiography as an effective procedure of first resort because it can be combined with embolotherapy.

Pictorial review: magnetic resonance imaging of benign soft tissue masses of the hand and wrist

Magnetic resonance imaging (MRI) is the imaging method of choice for evaluating the presence and extent of soft tissue masses. It is particularly useful for assessing masses in the wrist and hand, where benign lesions predominate. A specific diagnosis may be made, or strongly suspected, from the characteristic MRI features found in certain conditions like ganglion, haemangioma, arteriovenous malformation, giant cell tumour of the tendon sheath and lipoma.

MRI of soft tissue tumors

Magnetic resonance imaging (MRI) is the only noninvasive method of defining a soft tissue tumor. The extent of the tumor and the question of involvement or noninvolvement of various adjacent tissues and structures can be determined. This information, determination of lymphatic and distant metastatic spread, is invaluable for staging and management of the disease. Whether or not the tumor type can be reliably determined, or even whether the malignant or benign nature of the tumor can be ascertained on MRI examination, is open to question. Review of the literature indicates proponents on both sides of the issue. This review illustrates the imaging features that are relevant to suggesting a histologic diagnosis, and the pitfalls that are encountered in trying to determine the malignancy or benignity of a lesion. The clinical significance of these determinations is also discussed.