CASE 10328 Published on 21.09.2012

Intradural Spinal Lipoma Without Spinal Dysraphism With Subcutaneous Extension

Section

Neuroradiology

Case Type

Clinical Cases

Authors

1Nitesh Shekhrajka, Krishnakumari A. Modi, Ajay Mehta, Vishesh Agarwal, Karam Chand Sharma

Patient

65 years, male

Categories
Area of Interest Musculoskeletal soft tissue, Musculoskeletal spine, Neuroradiology spine, Management, Musculoskeletal system ; Technique CT, CT-High Resolution, MR
Clinical History
20 year history of gradually progressive swelling on the back in the inter-scapular region. Associated progressive para paresis in lower torso and lower limbs and urinary retention for past 6 months.
Imaging Findings
Large, multilobulated, soft tissue mass lesion measuring 28 cm x 20 cm (approx.) Located subcutaneously in the back in the midline with right paraspinal predominance from Th7 to L1. Mass involving the musculature and thoracic cage.
Erosion of the right sided pedicles from Th9 to Th12. Expansion of the intervertebral foraminae from Th9 to Th12 with extension via the enlarged foramina into the extramedullary intradural compartment of spinal canal.
Pressure erosion of the adjacent lower right ribs to extend in the posterior mediastinum.
The mass is hypodense on CT. No calcification.
On MRI, the mass is relatively well defined and is hyperintense on T1 and T2 –weighted images with thin linear streaks of low signal intensity. The lesion shows suppression on fat saturated images on MR - represents Lipoma.
Discussion
BACKGROUND-

Spinal lipomas are congenital tumours usually presenting as slow growing benign tumours. 60% are localised intradurally and 40% extradurally.[1]

Intradural spinal lipomas are slightly more common in men than in women (2, 6, 7)
Lipomas are benign tumours that are histologically identical to normal body fat (4).

Intradural spinal lipomas are rarely diagnosed in patients who do not have neural tube defects. These congenital, histologically benign neoplasms account for less than 1% of all spinal cord tumours[2, 3] and are most often found in cervical and thoracic regions.
It is rare to diagnose intradural spinal lipoma in patients who do not exhibit dysraphism (5)
Most spinal lipomas originate in the dorsal juxtamedullary region of the spinal cord (10);
however, the embryologic defect that leads to the development of these tumours is unknown. Several hypotheses have been proposed to explain how spinal cord lipomas arise. The most widely accepted theory is that a developmental malformation occurs during the formation of the neural tube and leads to inclusion of embryonic crests of fat cells (6, 11). Although the aetiology is unclear, many characteristics of these tumours indicate that they are growing hamartomas. Specifically, they are relatively often associated with other spinal malformations such as spina bifida, and histological evidence also points to a hamartomatous origin (2, 6, 8, 12).
Guifffre's 1966 review stressed that most spinal lipomas are subpial, and are never completely enclosed by neural tissue.(2)

CLINICAL PERSPECTIVE-

The typical neurological manifestation of this condition is a slowly progressive course of spastic para- or tetraparesis and pain (2, 8, 9, 10). Most of these tumours extend over multiple spinal levels and reach a significant volume before they are detected.The typical extent is at least four or five vertebral body segments. The characteristic finding on myelography is widening of the spinal cord in the area of the tumour (13)

IMAGING PERSPECTIVE-
The intimate association of spinal lipomas with adjacent neural structures is best delineated with MRI (14), and high signal intensity on T1-weighted images is characteristic of lipomas. T2-weighted images of these lesions tend to be variable, and the mass may appear hyper-, iso- or hypointense compared to normal neural parenchyma (3, 5, 15).

MANAGEMENT IN THIS PARTICULAR CASE-

D8-L1 laminectomy and subtotal resection of tumour were performed.
Spinal adhesions were relieved under microscope.
The diagnosis of lipoma was confirmed on histopathology.
The patient showed good neurological improvement post-operatively.
Differential Diagnosis List
Intradural Spinal Lipoma Without Spinal Dysraphism With Subcutaneous Extension
Meningioma
Myelomeningocele
Metastatic tumour
Neurofibroma
Lipoma
Final Diagnosis
Intradural Spinal Lipoma Without Spinal Dysraphism With Subcutaneous Extension
Case information
URL: https://www.eurorad.org/case/10328
DOI: 10.1594/EURORAD/CASE.10328
ISSN: 1563-4086