Intramuscular granular cell tumor of the forearm: a rare case and diagnostic challenge.
Jiro Ichikawa, Tomonori Kawasaki, Masanori Wako et al.
✦ AI-curated · Sources linked
Case in brief
A 55-year-old woman presented with a painless, enlarging mass on the ulnar side of her left forearm. MRI indicated a poorly defined intramuscular lesion in the flexor carpi ulnaris, with features suggestive of a granular cell tumor (GCT). Histopathological examination confirmed the diagnosis, revealing benign GCT characteristics. Despite positive surgical margins, no recurrence was noted at two-year follow-up.
What made this case unusual
The case highlights the presence of the stripe sign on gadolinium-enhanced MRI, which may be more specific for GCT compared to other imaging findings.
Diagnostic / clinical pearl
Histopathological confirmation is crucial for diagnosing granular cell tumors, as MRI findings can be variable and nonspecific.
Why it matters
This case underscores the importance of recognizing specific MRI features, like the stripe sign, which may aid in the differential diagnosis of intramuscular lesions.