Epidural spinal cord compression as initial clinical presentation of an acute myeloid leukaemia: case report and literature review

The spinal cord compression revealing acute myeloid leukaemia is unusual. Nine cases
have been reported from 2005 to 2015 3]–11] (Table 1). It often appears like a solid tumour known as granulocytic sarcoma or myeloid,
or also chloroma as seen in our patient 12]. It corresponds to the migration outside of the bone marrow of myeloid cells that
proliferate on their own 1]. The first case was described in 1811 by Burns in 1893 and Dock who reported its
association with leukaemia 13], 14]. It is reported in 3.1 to 9.1 % of patients with acute myeloid leukaemia 15]. We found ten cases from 2005 to 2015 which were reported in literature. In those
cases epidural space was occupied by granulocyt sarcoma [3-9 11, 15]. Surgically excision
of the tumour appeared to be the first treatment option in these cases. Granulocytic
sarcoma is frequently diagnosed simultaneously with or after the start of an acute
myeloid leukaemia or may be the initial sign of a relapse in a patient in remission
3]–9], 11], 15]. In non-leukemic patients, myeloid granulocytic sarcoma usually precedes acute myeloid
leukaemia 16]. In 87 to 88 % of patients without hematologic abnormalities at diagnosis, acute
myeloid leukaemia develops in the 10.5 to 11 following months 17]. Myeloid sarcoma may occur in all tissues but they are frequently localized on the
skin, bone, soft tissues of the head and neck (especially on the orbit) and adenopathies
18]. Spinal localization and especially epidural is rare. Thoracic localization is the
most frequent spinal localization followed by lumbar and sacral localizations. Clinical
signs are in most cases made of spinal cord compression. Sometimes they involve isolated
rachialgia 3]–9], 11], 15]. MRI is the best choice for neuroimaging examination to show epidural tumour lesions.
It is also the best neuroimaging examination 3]–9], 11], 15] to show the epidural tumour lesions without being specific. Granulocytic sarcoma
is iso-intense in T1 and T2 with in general a contrast enhancement 3]–9], 11], 15]. The therapeutic strategy of this myeloid sarcoma is based on chemotherapy, radiation
therapy, surgical decompression and bone marrow transplantation and any combination
of these methods 3]–9], 11], 15]. 1n cases of granulocytic sarcoma in particular by acute myeloid leukaemia with neurological
signs, priority should be given to chemotherapy and/or radiation therapy rather than
surgery. In our patient the diagnosis of acute myeloid leukaemia was made from full
blood count after surgery. Surgery was only justified by the acuteness and quickly
worsening neurological disorders. Despite some cases of more or less complete neurological
recovery with a variable remission, most patients present with neurological sequellae
and die from haematological complications dominated by sepsis.

Table 1. Literature review from 2005 to 2015. characterization of acute myeloid leukemia associated
to spinal cord compression