Related Experiment Video
Updated: Jan 26, 2026

Microscopic Cyst Resection for the Treatment of Patients Diagnosed with Epididymal Cyst
Published on: March 31, 2023
Filar cysts in rare cases may progress in size, particularly when associated with filar lipoma
Kyoichi Seo1, Hirofumi Oguma1, Rieko Furukawa2
1Department of Neurosurgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, Japan.
Purpose:
Filar cysts (FCs) are detected incidentally on ultrasonography (US) of the neonatal spine. Their clinical significance has not been widely discussed in the literature because FCs are usually asymptomatic. This study aimed to investigate the clinical features of FCs and distinguish FCs that warrant attention.
Methods:
We retrospectively analyzed 396 patients with lumbosacral skin stigmata. Patients who were younger than 1 month old at reference underwent US initially, and those older than 1 month of age underwent magnetic resonance imaging (MRI) at the age of 5-12 months. Patients with an FC in the US underwent subsequent MRI at the age of 5-12 months. Patients with an FC were followed clinically for at least 3 years.
Results:
FCs were identified in 56 (14.1%) patients. Of the 195 children who underwent US initially, FCs were detected in 49 (25.1%) children. FCs were detected in seven children who underwent MRI initially. Of the 50 children with FCs who underwent MRI at the age of 5-12 months, FCs in 20 patients (40%) showed natural regression and FCs in 30 patients (60%) remained. Two of these 30 patients showed progression in size of the FC, and in both cases, the FCs were associated with a filar lipoma; however, the resected cysts were not neoplastic and did not have obvious clinical significance.
Conclusions:
Our study characterizes clinical features of filar cysts. Two-thirds of FCs remained in late infancy. The best sequence of MRI to follow-up FCs is heavily T2-weighted images.
Related Concept Videos
Genome Size and the Evolution of New Genes
Tumor Progression
Colon cancer is one of the best-documented examples of tumor progression. Early mutation in the APC gene in colon cells causes a small growth on the colon wall called a polyp. With time, this polyp grows into a benign, pre-cancerous tumor. Further...
Cell Size
Surface Area
Cells can take in nutrients and water via diffusion through the plasma membrane itself or through specific channels in the membrane. The area of the membrane surrounding...
mTOR Signaling and Cancer Progression
The mTOR pathway or the...
Brick Sizes
Modular bricks are the most common type and are sized to include the mortar joint, which is essential for...
Maximum Size of Aggregate

