|Case of the Week - Patient Summary 13939|
Peer Reviewed and Certified -
|Demographics: 44 y.o. man|
|History & Chief complaint:|
| 44-year-old man presented in 2008 with acute onset of confusion and dizziness. Brain MRI scan showed a lesion in the left temporal lobe. A biopsy of the lesion was performed in 2009. He presented almost exactly three years later, in 2011, for his regular follow-up Brain MRI scan. The clinical profile of the patient now includes progressive cognitive decline, severe motor dysfunction, muscle weakness and difficulty in speech. |
|Physical exam and Laboratory:|
| Neurological examination (March 2011) reveals signs of spasticity (muscle weakness, clonus, exaggerated deep tendon reflexes).
His drug screen was negative for meth and heroin. He did have evidence of rhabdomyolysis.
|Summary of Findings:|
|The first Brain MRI scan (March 2008) demonstrates the presence of an ill-defined , T2 hyperintense, T1 hypointense lesion in the medial part of the left temporal lobe, with no associated edema or mass effect. Post contrast images reveal no enhancement of the lesion. Interestingly, there is enlargement of the areas affected by the lesion.
Brain MRI scan (March 2011) shows an obvious increase in the size of the lesion which extends in the right cerebral hemisphere through the anterior commissure and the corpus callosum. The lesion demonstrates mass effect and is characterized by perilesional angiogenic edema and ring pattern of enhancement. The lesion contains areas of hemorrhage and necrosis.
All the aforementioned features are compatible with the malignant degeneration of a low grade astrocytoma to a high grade brain glioma (Multiforme Glioblastoma).
|Differential diagnostic list of a low -grade astrocytoma comprises of infarction , lymphoma and encephalitis.
The main differential diagnosis of a butterfly-type lesion includes GBM, lymphoma, oligodendroglioma and demyelinating disease.
| Secondary Glioblastoma, 3 yrs from primary astrocytoma |
|Confirmed by: Ιmaging findings and biopsy|
|Treatment and Followup:|
|He has been receiving chemotherapy schemes and undergoing radiotherapy. Currently, he is in bad clinical condition. He suffers from severe muscle weakness, cognitive decline and visual impairment.
|Patient Specific Discussion: (Also Read the Disease Discussion)|
|The patient underwent a course of radiation treatment on June 2010. Also, he has been receiving chemotherapy on a regular basis . So, we have to note that part of the tumor necrosis and enhancement as well as some of the white matter T2 hyperintesity changes are due to radiation effects .|
|Astrocytic tumors are divided into two large catego-
ries. Tumors with diffuse growth, characterised by poor prognosis, belong to the first category. They make up about 75% of all astrocytic neoplasms. Tumors with increasing (different) degree of anaplasia from low-malignant astrocytoma to glio-blastoma, characterised by the absence of clear macro- and
microscopic borders separating tumor with surrounding tissue, belong to this category.
The second category of tumors is delimited tumors, with better prognosis (pilocytic astrocytoma, pleomorphic xanthoastrocytoma and subependymal giant cell astrocytoma). They are characterised by a clear border between tumor and normal tissue.
The WHO classification (2000) divides diffuse astrocytic glioma into three groups according to the
degree of malignancy from low-grade astrocytoma (LGA) to anaplastic astrocytoma (AA) and then to glioblastoma (GBM). The criteria include the presence of nuclear and cellular polymorphisms, proliferation of vessel endothelium, presence of mitosis, and foci of necrosis. It should be noted, however, that despite benign histological structure, all infiltrative low-ma-
lignant astrocytoma have poor prognosis.
Low-degree astrocytoma has better prognosis than does the malignant form. Unfortunately, the prognosis of such diseases is always poor.
Macroscopically LGA has grey colour, various
consistency (from dense to gelatine-like) and it is difficult to separate it from brain tissue .
Microscopically, the fibrillary astrocytoma consists of mature tumor astrocytes, with a rare arrangement of cellular bodies and rather monomorphic nuclei. Mitosis, haemorrhages and proliferation of vessel endothelium are absent.
The CT image of LGA is a hypodense area without clear
borders with surrounding brain tissue . Sometimes,
isodense types of tumor can be observed, leading to their late diagnosis if only CT examinations were conducted. Intravenous contrast administration usually does not lead to density change, or it can result in a separate hyperintense foci on a background of hypodense zone.
On MRI, LGA is iso- or (more often) hypointense on
T1-weighted images . As a rule, the tumor is
hyperintense with relatively homogeneous signal on T2 sequences. FLAIR imaging leads to highly heterogeneous signal from tumor tissue.
However, even MRI poorly detects tumour borders. It should be noted that infiltrative growth leads to the spreading of tumour tissue beyond the area of signal change visible on the T2-weighted image.
The gradual transformation of LGA into AA and then to
GBM is a well-known fact. In such observations, it is possible to simultaneously visualise within the same tumor the density changes (on CT) and MR signal changes (on MRI), typical for separate nosological forms of glioma , a combination of different forms of glioma or transformation of changes on follow-up scans. Moreover, it is known that about 10% of benign lesions can develop into more (sinister) malignant forms.
GBM is the most malignant of all glial tumors, and it occupies a great portion of the astrocytoma spectrum. It is the most frequent primary CNS tumor, whose incidence is about 10–20% of all intracranial tumors . GBM makes up approximately half of all gliomas,
and it is the most frequent supratentorial tumor in adults; usually it is observed in patients after age 50 years and is rare before 30 years.
Recently, GBMs have been divided into primary or secondary types. Primary GEMs are more common in adults and arise de novo. Secondary GEMs are found in younger patients and represent the malignant degeneration from originally lower-grade astrocytomas. Tumors undergo a series of mutations before becoming GBMs. Macroscopically, GBM usually is a formation that has a heterogeneous structure with central necrosis and highly vascularised stroma.
According to histological data, GBM is a tumor with a high level of cytological atypia and mitotic a ...
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