DISCUSSION
We report the unusual cases of two children with symptoms suggestive for
acute myelopathy, who resulted both affected by Primary Intramedullary
Spinal Cord Lymphoma (PISCL). Though considered rare spinal canal
tumors, PISCL should always be included in the differential diagnosis of
acute myelopathy, because any delay in diagnosis and treatment could
significantly impact on the prognosis of this disease.
Among the oncological causes of compressive myelopathy in the pediatric
population, non- Hodgkin lymphomas (LNH) are the main group. LNHs are
represented by a heterogeneous group of malignant neoplasms of lymph
node tissue derived from the progenitors or mature B lymphocyte cells
or, with lower frequency, T lymphocyte cells. While in adult the
predominant subtype is low-grade, clinically indolent, lymphomas in
pediatric age are mainly high-grade and characterized by an aggressive
behavior (1). Extra nodal location in LNH of the child-adolescent, which
differs from that of the adult, is more frequent, with involvement of
the mediastinum, abdomen, head-neck district, bone marrow or central
nervous system (2). Symptoms often develop rapidly, over a period of 1-3
weeks (see Table 1 for signs and symptoms). The onset of
lymphadenopathy, with lymph nodes increased in size and indolent, is
common as well as compression symptoms on the surrounding structures.
Our two clinical cases emphasize how clinical presentation of LNH
frequently constitutes a challenge for the pediatrician because of the
variety of possible onset manifestations and the different types of
lymphomas and areas involved. For example: a chronic, deep, dull
abdominal pain, devoid of specificity and precise localization, can
characterize the onset of a LNH with primitively medullary localization.
The main cause of this clinical sign is the stimulation of the nerve
endings present in the wall of the bowel by the neoplasia (see Table 2
for red flags of PISCL).
However, acute abdominal pain is frequently a diagnostic challenge in
children due to the difficulty in correctly interpreting a nonspecific
symptomatology. Acute paraplegia in children is also a rare clinical
presentation of lymphoma, with signs and symptoms reflecting spinal cord
dysfunction. The 4 main etiological groups (see Table 3) of motor
paralysis and/or functional deficit of the lower limbs in pediatric age
consist of:
- trauma (for example, from falls or road accidents);
- vascular pathologies, including epidural spinal hematoma, caused by
the rupture of epidural veins in correspondence of a locus minoris
resistentiae following a sudden increase in intrathoracic or
intra-abdominal pressure, due to efforts (even when of low intensity
such as cough or defecation);
- inflammatory diseases (including primary infections, abscesses,
polyradiculoneuropathy and infection associated processes, such as
transverse myelitis and encephalomyelitis);
- compressions (tumors, syringomyelia) (11-12).
According to an Australian case study, the most common cause of acute
flaccid paralysis of the lower limbs (up to 47% of cases) is GBS (5).
Malignant compression of the spinal cord (MCSC), whether it is caused by
a primary tumor localization or as the consequence of a metastasis, can
be divided into two types, depending on location: extradural (the most
frequent in adults, extending from the vertebral bodies or from
structures external to the dura mater) and intramedullary (14). Despite
their impact on morbidity and mortality, only a small amount of data on
the incidence of the disease are available in the pediatric population.
Acute spinal cord compression can occur in a not negligible percentage
of children with cancer, often at the time of diagnosis (15). Tumors
associated with medullary compression in childhood are shown on table 4.
In an italian case study in pediatric oncology, motor deficit was the
onset symptom of MCSC in all patients, while pain was reported in 60%
of cases and sphincter deficit in 43% (3). MRI is the diagnostic
technique of choice in all cases when there is suspicion of medullary
involvement (3). This exam should be carried out as soon as possible
because the neurological prognosis is strongly related to the promptness
of spinal cord decompression surgery (11). Complications of spinal cord
compression, such as urinary dysfunction, fecal incontinence,
spasticity, painful syndromes and psychological sequelae are complex
problems for children and adolescents (13). According to the latest 2013
guidelines of the American Association of Neurological Surgeons and the
Congress of Neurological Surgeons, the use of glucocorticoids in acute
traumatic spinal cord injury is no longer recommended.
The American Academy of Emergency Medicine states that glucocorticoid
treatment remains an acceptable option. Many experts affirm that there
are compelling and undeniable data justifying the clinical use of
glucocorticoids, particularly in patients with incomplete lesions. The
molecule to be used should be methylprednisolone, administered
intravenously. The therapeutic scheme is:
30 mg/kg in bolus in 15 minutes
After 45’, 5,4 mg/kg infused every hour for 23 hours. (18)
A bladder dysfunction can lead to difficulties in urination associated
with changes in intravesical pressure, an increased risk of infection
and kidney damage as well as a source of social distress. Urinary
symptoms can be very variable, ranging from an increase in urinary
frequency to a complete urinary retention. It is therefore mandatory to
perform a proper neurological examination (complete with evaluation of
sphincter function and reflexes), a mintional diary, to measure residual
post-mintional volumes and to execute urodynamic studies. Similarly, the
presence of neurogenic bowel can be a source of serious social distress
and skin impairment. Laxatives or anti-diarrheal drugs with pelvic floor
rehabilitation can improve sphincter control (14). On the other hand,
several studies show how neurological recovery in childhood is better
than in adulthood (6) thanks to the greater plasticity of the immature
spinal cord (7-8). In a recent work, the presence of residual muscle
activity in children, found in electromyography analysis of the motor
sites located below the level of injury, documents the existence of a
residual descending influence from the spinal motor circuits. This
observation, independently of its immediate functional relevance, can
represent an objective indicator of the potential recovery of both
intentional and postural motor function (16). Physiotherapy, following
damage to the spinal cord, is still one of the key processes in the
rehabilitation of the patient (9-10). Age at the time of diagnosis,
location and degree of spread of the spinal cord injury are the main
prognostic factors for the recovery of gait. Children under 5 years of
age, with incomplete injuries, located in thoracic or lumbar spine, have
the best chance of functional recovery thanks to physiotherapy (17).