English

Abstract

Glioblastoma multiforme is a primary brain neoplasm, consisting of a genetically and phenotypically heterogeneous group of tumours.1 The term glioblastoma multiforme (GBM) was introduced by Cushing in the second half of the nineteenth century, while the first operation on a patient suffering from this type of tumour was conducted in Vienna in 19041. Ninety percent of glioblastoma multiforme cases develop de novo (primary glioblastoma) from normal glial cells by multistep tumorigenesis.1 The remaining 10% of gliomas are cases of secondary neoplasm, developing through progression from low-grade tumours (diffuse or anaplastic astrocytoma’s), which takes about 4–5 years.1 Secondary glioma is diagnosed mostly in persons with the mean age of 39 years, grows more slowly and has a better prognosis.1 Glioblastoma multiforme, which develops de novo, grows within 3 months. 1 Although the genetic basis, as well as the molecular pathways underlying development of primary and secondary gliomas are different these two types show no morphological differences.1 Alkaptonuria is an ultra-rare (1:250.000–1.000.000 incidence) autosomal recessive inborn error of catabolism of the aromatic amino acids’ phenylalanine and tyrosine due to a deficient activity of the enzyme homogentisate 1,2-dioxygenase. This leads to the accumulation of homogentisic acid (HGA, 2, 5- dihydroxyphenylacetic acid).2 HGA oxidizes to benzoquinone acetic acid (BQA), which in turn forms melanin-based polymers, deposited in the connective tissue of various organs, causing a pigmentation known as ochronosis, leading to dramatic tissue degeneration. 3 A severe form of arthropathy is the most common AKU clinical presentation.4