Quadrigeminal cistern lipoma

The clinical and radiological features of cisternal and pericallosal lipomas

PURPOSE

To demonstrate the clinical and radiological features of pericallosal and cisternal lipomas and to compare these two groups in terms of radiological and clinical features.

METHODS

This retrospective study included 23 patients diagnosed with pericallosal and cisternal lipoma between 2010 and 2017. The patients comprised 12 females and 11 males with a mean age of 38.8 years (range 12-69 years). Magnetic resonance imaging was applied to all the patients. Computed tomography (CT) was also performed in 10 patients.

RESULTS

9 lesions were pericallosal and 14 were cisternal (7 were right quadrigeminal cistern, 3 were left quadrigeminal cistern, 1 was interpeduncular cistern, 1 was left cerebellopontine cistern, 1 was right cerebellopontine cistern, and 1 was supracerebellar cistern). The mean size of the lesions was 18.7 ± 10 mm. The shape of the lesions was curvilinear in 10 patients (43.5%) and tubulonodular in 13 patients (56.5%). The mean CT density of the lesions was - 87.7 ± 25.6 HU. The size of pericallosal lipomas (mean 27.5 mm) was statistically significantly larger than that of cisternal lipomas (mean 13.1 mm) (p = 0.001). No statistically significant difference was determined between the two groups in terms of lesion shape (p = 0.478), gender (p = 0.707), age (p = 0.639), and symptoms (p = 0.084).

CONCLUSIONS

In this study, the incidence of pericallosal lipomas was 0.011% and the incidence of cisternal lipomas was 0.017%. Although rare, the knowledge of the clinical and radiological features of pericallosal and cisternal lipomas will play an important role in the accurate diagnosis and follow-up of the patient.

Holoprosencephaly or severe hydrocephalus: T1 sequence tells the story

Intracranial lipoma is a relatively rare benign lesion. Many are incidental findings; however, some others may present with headache, hydrocephalus or other neurological symptoms; thus, correct diagnosis of this condition is important. These lesions are of high signal intensity on T2-weighted MRI and especially those close to cerebrospinal fluid (CSF) spaces, can easily be overlooked in the background of high signal intensity of CSF. Here, we present a case of tectal lipoma, with subsequent severe hydrocephalus and absence of septum pellucidum which was initially misinterpreted as a form of holoprosencephaly, due to inadequate attention to T1-weighted images.

Role of intraoperative squash smear cytology as a diagnostic modality in lipoma of quadrigeminal cistern

Quadrigeminal lipoma is a rare tumor that has been categorized as developmental malformation rather than a hamartoma or true neoplasm, due to its origin from abnormal persistence and mal-differentiation of meninx primitiva during the development of the subarachnoid cisterns. Reported admixture of adipose tissue with heterotopic elements also supports a developmental origin. Quadrigeminal lipomas are frequently asymptomatic and detected incidentally. Though a favorable clinical course is usually expected, recurrences may occur due to partial removal of lesions in close relation to vital structure. We describe the role of intraoperative squash smear cytology as a diagnostic aid in quadrigeminal cistern lipoma and an alternative to frozen sections that are technically difficult to obtain due to presence of lobules of fibro-adipose tissue. With radiological correlation, squash cytology can be an economical method for intraoperative diagnosis, pending subsequent histopathological confirmation.

Quadrigeminal plate cistern lipoma

Intracranial lipomas are rare benign neoplasms accounting for <0.1% of all primary brain tumours. Most lipomas were incidentally detected by autopsy or computed tomography (CT).These slow growing benign lesions are usually asymptomatic and rarely require surgery. We report the case of a 70-year-old Nigerian woman who presented with persistent headaches following involvement in a road traffic accident 20 days previously. CT demonstrated a quadrigeminal cistern lipoma with no evidence of raised intracranial pressure or compression of neural structures. Her headaches resolved with conservative care. We describe the CT findings with a brief review of the literature.