Primary spinal cord neoplasia (PSCN) include a group of neoplasia which originate from the parenchyma of the spinal cord or from tissues that are contained within the surrounding spinal canal such as meninges and nerves among many others [1,2,3]. The prevalence of the PSCN has been reported to range from 4 to 8% of all the neoplasia involving the nervous system [1, 2]. However, a prevalence of 12% was once reported in the literature [6]. When considering secondary spinal cord neoplasia (SSCN), it has been found that majority (84%) are extramedullary and the remaining 16% of them are intramedullary. Additionally, over 50% of the SSCN are a result of metastatic lung carcinomas particularly small cell lung carcinoma (SCLC) [7, 8]. Both males and females are affected equally with PSCN [6, 7, 9]. Paediatric PSCN are rare compared to the general population, and they account for less than 6% of all the SCN tumours [10]. According to the Central Brain Tumor Registry of the United States report of 2012, it was reported that the incidence rate of PSCN among children is 0.19 per 100,000 person-years compared to 0.7 per 100,000 person-years in adults, and the incidence rate increases with the increase in age [11].
Anatomically, the PSCN have been divided into two main types: extradural and intradural types based on their vicinity to the thecal sac which encloses the spinal cord and cauda equina [12, 13]. Extradural PSCN are located outside the thecal sac, and they account for approximately 60% of all PSCN [12]. The intradural types whose incidence is 30% are further subdivided into two types: extramedullary and intramedullary types [6, 13, 14]. Approximately 10% of the PSCN are naturally associated with both intradural and extradural components of the spinal cord parenchyma [12]. Intradural extramedullary PSCN adhere to the external areas of the spinal cord parenchyma, and the intradural intramedullary PSCN usually affect the true spinal cord parenchyma [6].
PSCN may sometimes be categorized based on the type of cells and/or tissue affected [15]. Based on this categorization, there are gliomas, meningiomas and nerve sheath neoplasia. Gliomas arise from glial cells; for example, ependymoma, astrocytoma, and oligodendroglioma [6, 9, 14]. On the other hand, the peripheral nerve tumours include schwannoma and neurofibromas [3, 8]. Of the gliomas, astrocytomas are the most common tumours with male predilection followed by ependymomas [1, 2, 9]. Meningiomas are the most common types of PSCN with unknown aetiology albeit they have been linked with radiation and neurofibromatosis [16]. They have female predilection with a reported male-to-female ratio of 1:4 [16].
PSCN present clinically with a variety of clinical symptoms. One study that included children aged less than 3 years of age who were diagnosed with intramedullary tumours reported that the majority of the children were presenting with pain and other symptoms included motor regression, abnormal gait, torticollis, and kyphoscoliosis [17]. Other studies reported that pain, weakness, and sensory disturbances are the commonest symptoms among 430 patients who were both children and adults [1, 18, 19]. Therefore, this shows that pain is the most common clinical feature among patients with PSCN.
Majority of the PSCN are benign and tend to be extradural unlike intramedullary ones, which are by far the rarest PSCN accounting for only 7% [20]. As it is for benign PSCN, even malignant neoplasia affecting the spinal cord are commonly found to be intradural, and most of them result from metastasis in the surrounding tissues particularly the spines [5,6,7].
This study aimed to determine the frequency of occurrence of the different PSCN for the cohort of 53 patients who attended at a tertiary hospital in the central part of Kampala, Uganda, between January 2011 and December 2019.
