Retrorectal developmental cysts in adults: clinical and radiologic-histopathologic review, differential diagnosis, and treatment

Developmental cysts are the most common retrorectal cystic lesions in adults, occurring mostly in middle-aged women. They are classified as epidermoid cysts, dermoid cysts, enteric cysts (tailgut cysts and cystic rectal duplication), and neurenteric cysts according to their origin and histopathologic features. Although developmental cysts are often asymptomatic, patients may present with symptoms resulting from local mass effect (eg, constipation, rectal fullness, lower abdominal pain, dysuria), with a palpable retrorectal mass at digital rectal examination, or with a complication. Infection with fistulization, bleeding, and malignant degeneration are the major complications of developmental cysts. A well-defined, unilocular or multilocular, thin-walled cystic lesion is the main imaging feature. Uncommonly, a sacral bone defect and calcifications are associated with developmental cysts. The differential diagnosis includes cystic sacrococcygeal teratoma, anterior sacral meningocele, anal duct or gland cyst, necrotic rectal leiomyosarcoma, extraperitoneal adenomucinosis, cystic lymphangioma, pyogenic abscess, neurogenic cyst, and necrotic sacral chordoma. Complete surgical excision is indicated to establish the diagnosis and avoid complications.

[Inner ear and subarachnoid spaces: relations and diseases]

The purpose of this article is to describe, with 5 clinical cases, the physiological communications between the inner ear and the subarachnoid spaces (SAS) and present the imaging features with regard to. Therefore we briefly illustrate abnormal communications between SAS and perilymphatic fluids in certain cochlear and internal acoustic meatus (IAM) malformations and their consequences. Imaging features may depict diffusion pathway of bacterial meningitis to membranous labyrinth via the cochlear aqueduct or via the IAM. Rarely, in some patients referred for cochleovestibular symptoms, imaging features may display skull base tumors involving the area of cochlear or vestibular aqueduct aperture. Therefore, in patients referred for cochleovestibular symptoms, MR and CT study should carefully scrutinise not only the IAM but also the aperture of the cochlear and the vestibular aqueducts and the cerebellopontine meninges.

[Imaging mechanical complications of inferior vena cava filters]

Filter placement within the inferior vena cava is performed to prevent pulmonary embolism in patients with contraindications or failure of anticoagulant therapy. Several complications of vena cava filters have been described. However, mechanical complications related to IVC filters may not be of any clinical significance. The purpose of this pictorial essay is to present the imaging features of complications related to inferior vena cava filter placement.

MR angiography for the long-term follow-up of dissecting aneurysms of the extracranial internal carotid artery

OBJECTIVE

We used MR angiography to examine and follow up the changes of dissecting aneurysms of the extracranial internal carotid artery (ICA).

MATERIALS AND METHODS

We retrospectively reviewed the records of 101 consecutive patients with dissecting aneurysms of the extracranial ICA. Twenty patients with 26 spontaneous dissecting aneurysms were followed up with MR angiography every 1-2 years (men, 16; women, four; age range, 28-67 years; mean age, 51 years).

RESULTS

The mean duration of follow-up was 41 months (range, 10-93 months). At MR angiography follow-up, 20 aneurysms did not change, four decreased from their original size by 33-53% (mean, 43%), and two resolved. One patient had an asymptomatic recurrent dissecting aneurysm of the extracranial ICA. Clinically, no patient had a thromboembolic stroke or transient ischemic attack during the follow-up period.

CONCLUSION

MR angiography revealed that dissecting aneurysms of the extracranial ICA remain stable, decrease in size, or resolve--but they do not increase in size.

Long-term follow-up of aneurysms developed during extracranial internal carotid artery dissection

OBJECTIVE

To evaluate the clinical course of aneurysms developed during extracranial internal carotid artery (ICA) dissection.

BACKGROUND

Aneurysms developed during extracranial ICA dissection are detected angiographically in 5 to 40% of cervical artery dissections. The clinical and radiologic course of these aneurysms is not known, and it is not known how they should be treated.

METHODS

Fifty-eight consecutive patients with extracranial ICA dissection were reviewed, and those with radiographically detectable dissecting aneurysm at the acute stage or during early follow-up were included in this study. All patients had regular clinical and MR angiography examinations. Sixteen patients (27.5%) with a total of 20 ICA dissecting aneurysms were followed for a mean period of 36.9+/-21 months (range, 10 to 93 months).

RESULTS

No clinical symptoms suggestive of aneurysmal rupture or embolization from the aneurysm were identified. Extracranial ICA aneurysms remained unchanged in 65% of patients, were resolved in 5% of patients, and decreased in size in 30% of patients.

CONCLUSIONS

The clinical course of dissecting aneurysms was benign, although spontaneous radiologic resolution occurred rarely. Medical management with antiplatelet therapy alone (after early anticoagulation) is generally sufficient, and surgical management was seldom required.

Diffuse cavernous hemangioma of the rectosigmoid colon: imaging findings

Diffuse cavernous hemangioma of the rectosigmoid colon (DCHR) is an uncommon disease that affects mainly young adults. As the main symptom is non-specific chronic rectal bleeding, the clinical diagnosis is difficult and often delayed. In this essay, we illustrate the imaging features of DCHR, including plain radiograph, barium enema, CT and MR study, and echoendoscopy. Pitfalls in diagnosis and the role of imaging study in the diagnosis, in the preoperative staging, and in the follow-up of the patients are defined.

MR imaging of diffuse cavernous hemangioma of the rectosigmoid colon

OBJECTIVE

We retrospectively reviewed five pathologically proven cases of diffuse cavernous hemangioma of the rectosigmoid colon to define the MR imaging features of this entity.

CONCLUSION

Diffuse cavernous hemangioma of the rectosigmoid colon is revealed as rectosigmoid wall thickening with high signal intensity on T2-weighted MR images. Such wall thickening is associated with abnormal perirectal fat. The extent of bowel involvement and extrarectal locations are well shown on T2-weighted MR images.

Perichiasmatic granuloma occuring after radical mastoidectomy: MR findings

A case of chronic chemical meningitis occurring after a radical mastoidectomy is reported. Imaging and surgical findings were suggestive of a dissemination of cholesteatoma debris within the subarachnoid spaces. Chemical meningitis has been described in epidermoid and dermoid cyst rupture. This report illustrates that clinicians should be aware of this possible complication. Skull base imaging is mandatory before considering the diagnosis of idiopathic meningitis. Only treatment of the abnormal communication between cerebrospinal fluid and middle ear may eradicate the origin of this rare meningitis.