Case Report
In July 2020, a 49-year-old woman was referred to our orthopedic spine
clinic by an orthopedist colleague with diagnosis of lumbar disc
herniation causing cauda equina syndrome. She had low back pain from six
months ago, which was aggravated since the last week and was severe
enough to completely disable the patient from her job and daily life.
She described it as radicular to both lower extremities. It was
aggravated by a short walk, 10 steps, and relieved only partially by
lying decubitus and rest for at least 30 minutes. She described
nocturnal pain since the beginning, but had no fever, malaise, and
history of recent trauma, drug, or alcohol abuse. She mentioned no
perianal/perineal anesthesia but some paresthesia of dorsal aspect of
both feet.
On past medico-surgical history, she had invasive ductal carcinoma of
right breast (ER-, PR-, HER2-) and had undergone right lumpectomy
(2009). In 2017, she developed the same pathology in her left breast and
was treated by left lumpectomy. She underwent standard chemoradiotherapy
regimen after both surgeries and had no sign of recurrence in her
regular follow-up.
On examination, there was no sign of skin rash or palpable mass in
lumbar area. She had difficulty in walking. Mild tenderness was found
over the lower lumbar vertebrae. Straight leg raise (SLR) and Cross SLR
tests were positive bilaterally. The lower extremity muscle forces were
4/5 proximally and 3/5 distally. The dorsiflexion force of both ankles
was 2/5. No sensory deficit was elicited. Patellar and Achilles deep
tendon reflexes were decreased in both sides. There was no Babinski
sign.
The magnetic resonance imaging (MRI) was in favor of a severe L4-L5 disc
herniation with a large teardrop shaped sequestrum, which migrated
caudally and caused severe canal stenosis at L5-S1 level. Sagittal and
axial cuts showed compression of both L5 roots by the sequestrated disc
in the L5-S1 neural foramina (Figure 1). However, due to the history of
breast cancer and some MRI features, discussed in the ‘discussion’
section, we were suspicious of the diagnosis of DS. Her past follow-up
positron emission/ computed tomography (PET/CT) in November 2019 showed
increased FDG uptake in L5 and lower L3 endplate, which was interpreted
as degenerative changes with no sign of metastatic lesions. Her last
whole body bone scan (May 2020) also had shown only degenerative changes
in L5.
Considering the eminent CES, we scheduled the patient for urgent
decompressive laminectomy and discectomy. We performed the surgery
through posterior midline incision by bilateral partial laminectomy and
foraminotomy. However, after laminectomy, we found suspicious lobular
tissue at the level of L4-L5 intervertebral disc bulging posteriorly
into the spinal canal. As the patient had known history of breast
cancer, we considered the tissue as metastasis, and tried to decompress
the spinal canal and foramina by carefully removing the intra-canal
mass, first diagnosed as a disc sequestrum on MRI by radiologist. Mass
resection was performed with as minimal dissection as possible to avoid
probable local tumor contamination. The whole resected tissue was sent
for pathologic study (Figure 2). The intervertebral disc was completely
intact, and we did not perform any discectomy. After sufficient
decompression of canal and nerve roots, standard hemostasis and wound
closure was performed.
The patient started ambulation the evening after surgery according to
our postoperative protocol. Lumbar pain was significantly relieved. She
was discharged after two days.
The pathology report was positive for metastatic breast -invasive
ductal- carcinoma (Figure 3). We referred the patient to
radio-oncologist, and she underwent a course of radiotherapy. Now, we
have a seven-month follow-up of her, and she has had no recurrence so
far.