Medial notch of the superior border of the scapula: a rare anatomical variation mimicking a bone tumour.

The scapula is a flat, triangular bone overlying the posterior chest wall and forming the posterior aspect of the shoulder girdle. To the best of our knowledge, there is no previous description of a notch of the medial aspect of the superior border of the scapula in the literature. The imaging findings of a supero-medial scapula border notch mimicking a bone tumour are presented in this case report.

Imaging of giant cell tumour of the tendon sheath.

Giant cell tumours of the tendon sheath (GCTTS) and pigmented villonodular synovitis (PVNS) are part of a spectrum of benign proliferative lesions of synovial origin that may affect the joints, bursae and tendon sheaths. This review article describes the clinicopathological features and imaging findings in patients with GCTTS. GCTTS usually presents as a soft tissue mass with pressure erosion of the underlying bone. Magnetic resonance (MR) imaging of GCTTS typically shows low to intermediate signal on T1- and T2-weighted spin-echo sequences due to the presence of haemosiderin, which exerts a paramagnetic effect. On gradient-echo sequences, the paramagnetic effect of haemosiderin is further exaggerated, resulting in areas of very low signal due to the blooming artefact. Ultrasonography shows a soft mass related to the tendon sheath that is hypervascular on colour or power Doppler imaging.

Magnetic resonance imaging appearances of fibrous dysplasia.

Fibrous dysplasia is a developmental disorder in which normal bone marrow is replaced by fibro-osseous tissue. The radiographic, CT and scintigraphic appearances of this condition are well known. The MRI appearances of fibrous dysplasia have not been widely published. The lesions are largely isointense with areas of hypointensity on T(1) weighted images and appear heterogeneously hyperintense on T(2) weighted images. The enhancement pattern is patchy central, rim, homogeneous, or a combination. The MRI features reflect the variable tissue components of this entity. This pictorial review aims at highlighting the MRI appearances, with pathological correlation.

Synchronous large tumoral pseudoangiomatous stromal hyperplasia (PASH) in the breast and axilla with subsequent carcinoma in the contralateral breast: routine and strain imaging with histopathological correlation.

Pseudoangiomatous stromal hyperplasia (PASH) is a benign breast disorder with the tumoral variety being extremely rare. We report a rare case of synchronous, massive axillary and breast tumoral PASH in a 55-year-old post-menopausal woman. Mammography, ultrasonography and sonoelastography features are illustrated with histopathological correlation. A high-grade invasive ductal carcinoma was detected in the contralateral breast on annual follow-up imaging. Radiologists need to be familiar with the imaging appearances of PASH and be aware of its association with subsequent cancer risk. To the best of our knowledge, the present case of synchronous tumoral PASH in the breast and axillary tissue is the second reported case till now.

Metanephric adenofibroma: report of a case and review of the literature.

The recent recognition of a variety of pediatric renal tumors of different biologic behavior places an ever-increasing demand on the surgical pathologist for an accurate diagnosis. Although metanephric adenofibroma is one of the rarest benign renal tumors, the clinical importance of correctly diagnosing it cannot be overemphasized because it can potentially be mistaken as Wilms' tumor. We describe the clinical, radiologic, and pathologic features of a case of metanephric adenofibroma and discuss its differential diagnosis. The neoplasm was composed of two discrete components: a major fibroblastic element and a minor immature epithelial element. The latter formed a small nodule beneath the renal capsule, which could barely be detected by magnetic resonance imaging. This subcapsular nodule, however, was slightly soft and tan and was distinctly different from the white, whorled cut surface of the main tumor. It was formed by closely packed small immature epithelial cells in a slightly edematous background, which was histologically identical to metanephric adenoma and closely resembled epithelial Wilms' tumor. Unlike Wilms' tumor, however, the epithelial cells were very bland with no mitoses. The main bulk of the tumor was formed by spindle fibroblastic cells that were cytologically similar to the spindle cells in congenital mesoblastic nephroma. The tumor, however, was well demarcated without the irregular infiltrating edges of congenital mesoblastic nephroma. In contrast to the randomly distributed epithelial element throughout the stromal component in previous reported cases of metanephric adenofibroma, our finding of the exceedingly small and discrete epithelial component expands the known histologic spectrum of the disease. In addition, the presence of such minute epithelial nodule underscores the importance of diligent pathologic examination and careful sampling of tissue for histologic examination.

Day case hematuria diagnostic service: use of ultrasonography and flexible cystoscopy.

OBJECTIVES: To assess the efficacy of a day case diagnostic service employing ultrasonography and flexible cystoscopy in the evaluation of patients presenting with painless gross hematuria. METHODS: From July 1994 to June 1997 a prospective study was conducted for 312 consecutive patients presenting with painless gross hematuria. They were evaluated in a day case diagnostic service setting, where ultrasonography and flexible cystoscopy were performed together with other laboratory investigations. Intravenous urography was subsequently performed for possible additional diagnostic information. RESULTS: Eighty-one urinary malignancies were detected in 78 patients; 51 were carcinoma of the bladder, and the next most common was renal cell carcinoma (n = 15). Definitive diagnoses were made in 68 patients and an abnormality was noted in 9 other patients after the day case workup. The day case diagnostic workup has led to highly selective use of computed tomography scans with high diagnostic yield; intravenous urography only added important diagnostic information, not available from the earlier workup, in 9 patients. CONCLUSIONS: Day case diagnostic service is a feasible arrangement. By combining ultrasonography and flexible cystoscopy, most carcinomas were diagnosed and abnormalities detected. Such a service enhances rapid completion of diagnostic workup, and operations for surgical conditions can be scheduled more promptly.

Intrafracture fluid: a new diagnostic sign of insufficiency fractures of the sacrum and ilium.

MRI is generally regarded as being sensitive but non-specific for the detection of insufficiency fractures affecting the sacrum and pelvic ring. The finding of intrafracture fluid is described in two elderly patients with insufficiency fractures. This MR feature is believed to be a new diagnostic sign of these fractures affecting the sacrum and ilium.

Case report: intraventricular meningioma with cerebellopontine angle and drop metastases.

A 34-year-old Chinese woman underwent successful gross total excision of a benign fibroblastic meningioma, pre-operatively diagnosed by computed tomography (CT), arising from the left lateral ventricle of the brain. After a quiescent period of 5 years, CT and magnetic resonance imaging (MRI) demonstrated tumour recurrence at the same site. Despite two further excisions of progressively malignant intraventricular meningiomas and treatment with radiotherapy, the patient rapidly developed bilateral cerebellopontine angle and spinal drop metastases. CT and MRI were useful in demonstrating the location and extent of recurrent intraventricular meningiomas, as well as metastatic spread via the cerebrospinal fluid.

Lymphography--still useful in the diagnosis of lymphangiomatosis.

Lymphangiomatosis is diagnosed by lymphography in two patients. One case presented with life threatening pleural effusion and was found to have skin haemangiomata, underlying lymphangiomatosis and massive osteolysis of the pelvic bones in the same topographic distribution. The aetiology of this condition is discussed and the role of lymphography emphasized.

The magic angle phenomenon in tendons: effect of varying the MR echo time.

Increased signal intensity on magnetic resonance (MR) imaging of tendons arising from the magic angle phenomenon is well recognized. This study aimed to evaluate the effect of varying the echo time (TE) upon tendon signal intensity, and to determine if a modified TE value produces acceptable T1 and proton density (PD) weighted images. Fresh bovine tendons were imaged in a 1.5 T MR scanner using spin echo (SE) T1 and PD weighted sequences and utilizing a number of different coils. For each set of sequences, the tendon was orientated at 55 degrees to the main magnetic field (B0) and imaged using constant TR and incremental TE values. Signal intensity was measured on images at each TR/TE value and compared with the signal intensities of tendons orientated at 0 degree to B0, obtained using minimum TE values. This experiment was repeated with a 1.0 T MR scanner and utilizing a spine coil. The Achilles tendon of a human volunteer was similarly imaged using a general purpose flex coil. For bovine and human tendons orientated at 55 degrees to B0, the signal intensities decreased exponentially with increasing TE. A critical TE value exceeding 37 ms, for each sequence, reduced the signal intensities to the levels obtained with the tendons orientated at 0 degree to B0, such that the magic angle phenomenon could be avoided. Although there was variability of the signal intensities with different coils, the critical TE value remained constant and the anatomical clarity was not degraded. The critical TE value was unaltered using two MR scanners of different field strengths.

Percutaneous vertebroplasty: indications, contraindications, and technique.

Percutaneous vertebroplasty is an emerging interventional technique in which surgical polymethylmethacrylate is injected via a large bore needle into a vertebral body under imaging guidance. This technique provides increased strength and pain relief in vertebrae weakened by a variety of bone diseases. The current indication for vertebroplasty is intractable non-radicular pain caused by compression fractures due to osteoporosis, myeloma, metastases and aggressive vertebral haemangioma. Contraindications include bleeding disorder, unstable fracture and lack of definable vertebral collapse. Our technique of percutaneous vertebroplasty is illustrated in this pictorial review.

Case report: variable imaging appearances of angiomyolipomas of the liver.

Angiomyolipomas of the liver are rare benign tumours. We describe the variable imaging appearances of these tumours in three women. The first two patients underwent ultrasound, computed tomography (CT) and angiography, which demonstrated lesions resembling focal nodular hyperplasia and hepatocellular carcinoma, respectively. Both had histologically-proven liver angiomyolipomas surgically resected. The third patient was incidentally found to have typical features of multicomponented liver angiomyolipoma on CT. Variable proportions of fatty tissue in these tumours are the most likely explanation for their different imaging appearances on CT.

Case report: lymphangiomyomatosis with spontaneous peritoneal rupture.

Radiological appearances of pulmonary and retroperitoneal lymphangiomyomatosis in a 47-year-old Chinese woman are described. Onset of abdominal symptoms and development of ascites heralded spontaneous rupture of retroperitoneal lymphangiomyomatosis, which is illustrated on computed tomography.

Case report: perinephric angiomyolipomas in tuberous sclerosis.

Bilateral large perinephric angiomyolipomas in a young Chinese woman with tuberous sclerosis are reported. Computed tomography (CT) demonstrated large fatty masses, containing abnormally dilated blood vessels and muscle strands, within the Gerota's fascia bilaterally. There were multiple foci of involvement in both kidneys. The diagnosis was confirmed on histological examination of the excised left perinephric angiomyolipoma and nephrectomy specimens. The patient subsequently developed bilateral pneumothoraces which were surgically treated. High resolution CT showed extensive thin-walled cysts in both lungs.

Case report: magnetic resonance imaging of primary lymphoma of the cauda equina.

Malignant lymphoma of the central nervous system is usually confined within the cranium, with primary involvement of the spinal cord and nerve roots being very rare. The occurrence of primary lymphoma in the cauda equina in a 16-year-old Chinese male is reported. Contrast enhancement during magnetic resonance imaging is useful in accurately demonstrating disease extent prior to surgery.

Spontaneous rupture of renal tumours: the role of imaging in diagnosis and management.

This study aimed to evaluate whether patients presenting with spontaneous haemorrhage from renal tumours could be accurately diagnosed and initially managed conservatively, and evaluate the role of imaging in guiding the timing and type of subsequent operation. The clinical features, imaging findings and management of seven patients presenting with spontaneous rupture of renal tumour over a 5-year period were reviewed. The information from various imaging studies was evaluated in relation to the subsequent course of intervention. The tumours consisted of six angiomyolipomas and one renal cell carcinoma. In all cases, imaging studies were diagnostic, with computed tomography being the most useful single modality. Emergency surgery was required in one patient for evacuation of suspected infected haematoma and wedge excision of angiomyolipoma. Three elective nephrectomies were performed, while three other patients with ruptured angiomyolipoma were treated conservatively and remained well, without any intervention. In conclusion, patients presenting with spontaneous rupture of renal tumour can be managed conservatively initially. Imaging facilitates accurate pre-operative diagnosis, which was angiomyolipoma in all but one patient in this series. The subsequent intervention can be tailored according to the lesion type and the anticipated risk of re-haemorrhage.

Case report: Acute haemorrhagic presentation of trigeminal neuroma.

The acute presentation of trigeminal neuroma, due to sudden haemorrhage, in a 26-year-old Chinese man, is described. The clinical, CT and MRI features are reviewed together with the other four cases reported in the literature.

Magnetic resonance imaging of subcutaneous diffuse neurofibroma.

A 31-year-old woman presented with increasing pain and tenderness of a long-standing soft tissue mass on her back. MRI showed a network of interconnecting tubular areas, which were T1 isointense and T2 hyperintense relative to skeletal muscle, and displayed marked Gd-DTPA enhancement. The lesion was situated within the subcutaneous fat. Clinically and radiologically, this mass was considered to be a subcutaneous venous haemangioma. Histological examination of the excised mass showed a diffuse neurofibroma with ectatic vessels and entrapped adipose tissue. Similar MRI appearances of subcutaneous haemangioma and diffuse neurofibroma may result in failure to make the correct diagnosis and in inappropriate management.

Spontaneous renal pseudoaneurysm rupture presenting as acute intraabdominal haemorrhage.

A 39-year-old man with a known history of end-stage renal disease presented with hypovolaemic shock and acute abdominal pain. Blood-stained peritoneal fluid was present. Right perirenal and extensive mesenteric haematomas were seen at laparotomy and CT. Right renal arteriography demonstrated a small renal artery pseudoaneurysm, and embolization was performed. The patient later developed intractable sepsis and died despite nephrectomy and drainage of the infected haematomas. Although there is an increasing trend towards conservative management of spontaneously ruptured kidneys from benign causes, embolization followed by early surgery should be considered in cases of extensive intraabdominal haemorrhage.

Intraosseous venous drainage anomaly of the tibia treated with imaging-guided sclerotherapy.

A 23-year-old man presented with a pre-tibial soft tissue mass. Magnetic resonance images demonstrated the subcutaneous, intracortical and intramedullary components of an intraosseous venous drainage anomaly, which was confirmed by direct venography. Sclerotherapy using absolute alcohol was subsequently performed under imaging guidance with complete resolution of the subcutaneous component of the lesion.