Recurrent Cerebellar Liponeurocytoma with Supratentorial Extension

Abstract

662Cerebellar liponeurocytoma (LPN) is a rare central nervous system tumour recently recognized as a distinct clinicopathological entity. It was included in the previous 2000 edition of the World Health Organization (WHO) classification as a grade I neoplasm under the heading of glioneuronal tumours 1 . With increasing recognition of this entity and longer clinical follow-up periods in its investigation, it has become clear that this tumour has a rate of recurrence that is higher than previously thought and not compatible with a grade I designation. In light of the substantial rate of tumour recurrences, the current 2007 WHO classification assigns the cerebellar liponeurocytoma to WHO grade II tumour 2 . In this paper, we report a new case of a recurrent cerebellar LPN with supratentorial extension despite persistently benign histological features. To the best of our knowledge, recurrent cerebellar LPN with supratentorial extension has never been reported before, as the nine cases of recurrent cerebellar LPN published to date were confined to the posterior fossa. CLINICAL HISTORYA 42-year-old previously healthy man, presented with a fivemonth history of headaches, vertigo, visual disturbance and progressive unsteadiness of gait. On admission, neurological examination showed signs of cerebellar dysfunction, including ataxia, wide-based gait, right dysmetria on finger-to-nose testing and a positive Romberg sign. The fundus examination revealed unilateral papilloedema. Computed tomogram scan ( Figure 1) demonstrated a hypodense lesion within the vermis and right cerebellar hemisphere compressing the 4th ventricle and enhancing after contrast injection. Magnetic resonance imaging (MRI) scan showed a heterogeneous mass measuring 5 × 4 cm, characterized by discrete hyperintensity on T1-weighted images and high signal intensity on T2-weighted images. Several central parts of the lesion were very hyperintense on both T1 and T2-weighted sequences suggesting fat content. An intra-operative frozen section was reported as being consistent with a medulloblastoma. A gross total resection of the tumour was achieved. Histological examination of the surgical specimen revealed cerebellar tissue infiltrated by a highly cellular tumour formed by sheets of isomorphic small round cells (Figure 2). A significant proportion of the tumour demonstrated lipomatous differentiation characterized by large areas of cells containing a single cytoplasmic vacuole displacing the nucleus to the periphery mimicking mature fat cells (Figure 2A). There were only occasional mitotic figures and a low rate of proliferation Figure 2B) and neuron-specific enolase. Glial fibrillary acidic protein immunopositive tumour cells confirmed the presence of an additional glial component. All of these features were considered to be consistent with the diagnosis of cerebellar liponeurocytoma. A post-operative MRI performed three days after the surgery, demonstrated no residual tumour. No adjuvant radiation therapy was administered post-operatively. At the last rout...

Cerebellar Liponeurocytoma

“…[18][19][20] However, some tumors recur in the absence of such atypical histopathologic features. 21,22 It remains to be seen whether these atypical features are truly predictive of more aggressive biologic behavior.…”

Cerebellar liponeurocytoma: A case report and review of the literature

“…According to the study by Patel et al, in which 42 cases of liponeurocytoma from the literature were reviewed in 2009, there is no gender predominance (4). The WHO classified cerebellar liponeurocytoma as a grade II tumor, with a tendency to recur in the follow-up period (2).…”

“…Limaiem et al reported a recurrent cerebellar liponeurocytoma with supratentorial extension, and upon reviewing all 9 recurrent cases presented in the literature, the study suggested that the tumor may recur due to mitoses present in the lesion and >10% Ki-67-positive cells (2). However, one confusing element was that, even when treated with total resection, recurrence appeared unavoidable, showing that the cerebellar liponeurocytoma was similar to a malignant lesion (3).…”

“…Since it was first reported in 1978 (1), several names had been applied, such as lipomatous medulloblastoma, medullocytoma, neurolipocytoma, lipomatous glioneurocytoma and lipidized mature neuroectodermal tumor of the cerebellum (1). In 2000, The World Health Organization (WHO) classified this rare tumor as a distinctive entity, prior to characterizing it as a grade II tumor in 2007 (2). Cerebellar liponeurocytoma is most commonly found in adults, without gender predominance (2-4).…”

“…The current preferred treatment strategy is radical surgery, and adjuvant radiotherapy is recommended in cases of residual tumor. As the tumor has potentially long-term malignant characteristics, close follow-up is recommended (2)(3)(4). However, the clinical characteristics and optimal treatment strategy of the cerebellar liponeurocytoma remain unclear.…”