PSEUDOTUMORAL TOPHACEOUS INVOLVEMENT OF THE ACHILLES PARATENON.

Gout is the most common form of microcrystalline arthropathy which usually does not pose a diagnostic challenge when patients have typical presentation, appropriate biochemical picture and classical radiographic appearance. However, formation of gouty tophi in unusual locations and with atypical presentations may mislead clinicians and radiologists, thereby justifying gout nickname as the "great mimicker". When interpreting images of tendon related masses, radiologists should be aware of gouty tophi as a possible differential given its variable and nonspecific imaging appearance. In this article, we present a case of a patient with a painless tophaceous gout nodule, adjacent to the Achilles tendon.

New concepts in understanding evolution of desmoid tumors: MR imaging of 30 lesions.

The objective of this study was to evaluate the appearance and the natural evolution of desmoid tumors on MR imaging, given histologic correlation. The MR images of 30 desmoids (20 primary and 10 recurrent) in 26 patients were scored for a multiplicity of morphological parameters, signal intensity (SI) on different pulse sequences, and behavior after contrast administration. Natural evolution was evaluated in 2 primary and 3 recurrent lesions, and correlated with evolution on histologic specimens. Desmoid tumors are mostly found in muscles of shoulder and hip girdle and are often fusiform with partially ill-defined margins. Rare subcutaneous desmoids have a more stellar morphology. Variable amounts of low-SI areas are present on all sequences. On T1-weighted images (T1-WI), most lesions are near homogeneous and isointense to muscle, whereas on T2-WI they are more heterogeneous with an overall SI equal to or slightly lower than fat. Histologic correlation reveals that SI on T2-WI cannot be explained solely by cellularity. After initial growth, spontaneous evolution of desmoids is characterized by shrinking and an increase in low-SI areas on T2-WI. While distal lesions shrink, the more recent lesions in asynchronous multicentric desmoids have a tendency to develop proximally in the same limb, and should not be confused with recurrences. Fast growth, extracompartmental spread, and bone involvement are often seen in recurrences. Follow-up MR imaging of desmoids indicates natural regression of desmoids and more aggressive behavior of recurrences, which may justify a more conservative therapeutic approach.

Anal tenesmus caused by seminal vesicle cyst.

Congenital cysts of the seminal vesicles with ipsilateral renal aplasia or dysplasia are rare but have been well described in the literature. We report the first case where anal tenesmus was the only presenting symptom. Another unique feature was the combination of this anomaly with a duplication of the inferior vena cava.

Chondrosarcoma of the skull base: CT, MR and pathological features.

We report on CT and MR image findings of a skull base chondrosarcoma. Chondroid mineralisation, a histological feature of chondrosarcoma, can be recognised on CT and is, together with the off-midline position of the tumour, the most characteristic finding. Differentiation is usually made by histological and immunocytochemical staining. Surgery, proton radiation therapy and stereotactic single high-dose irradiation have been used to treat patients with chondrosarcoma. It is worth mentioning that it was likely that the chondrosarcoma in our patient represented a malignant degeneration of an enchondroma that had been resected 30 years earlier.

Cervical spinal arteriovenous malformation.

Cervical spinal arteriovenous malformations and fistulas are rare but important entities because they are potentially curable. MRI and angiography are the most useful imaging modalities for the diagnosis. On contrast-enhanced CT imaging, they can mimic a tumor. A case report of cervical spinal arteriovenous malformation, initially believed to be a tumor, is presented.

Spontaneous rupture of the bladder: an uncommon finding on excretory urography.

A case of recurrent intraperitoneal bladder rupture is reported. Tearing occurred after minor trauma in a woman who had suffered a fracture of the pelvic rim 6 years earlier. Spontaneous rupture of the bladder is rare. The symptoms of an intraperitoneal bladder rupture may suggest intestinal disease and intravenous urography may be misleading. A retrograde cystogram is required to obtain the diagnosis.

Microgeodic phalangeal syndrome in an infant.

A new case is reported of the curious disease described by Maroteaux as Microgeodic phalangeal syndrome in infancy, of unknown etiology. The purpose of this communication is to describe an additional case of this rare condition, described for the first time by Maroteaux in 1970, and affecting the fingers of infants and children. The condition consists of a swelling of the fingers and multiple microgeodes in the phalanges. It is a benign disease and the lesions disappear totally after a few months.