Benign Schwannoma of the Thumb; a diagnostic challenge

Abstract

Benign Schwannomas are one of the less frequently encountered soft tissue tumours of the hand. We report an interesting case of an 80-year-old gentleman with a painful soft tissue swelling on the radial aspect of his thumb. Ultrasound revealed a well-defined lesion separate from bone and tendon, with mixed echogenicity and moderate internal vascularity. Magnetic resonance imaging demonstrated a 15 × 10 × 23mm lesion with low signal on T1 and high signal on T2. Following surgical excision, histology confirmed benign schwannoma.

Rare Benign Tumors and Tumor-Like Lesions of the Hand without Skin Damage—Clinical, Imagistic and Histopathological Diagnosis, Retrospective Study

“…Tumor mobility in the transverse plane, with its significant limitation in the longitudinal plane, can guide the diagnosis [ 2 ]. Although the Tinel sign is present in 5% to 75% of schwannoma cases, in our study group, it was present in 100% [ 2 , 22 ]. The preoperative presence of neurological signs is suggestive of an unfavorable prognosis [ 2 ].…”

“…The preoperative presence of neurological signs is suggestive of an unfavorable prognosis [ 2 ]. MRI examination can make the diagnosis of schwannoma in 90% [ 22 , 23 ]. However, no imaging study has a specificity above 95% in its diagnosis [ 23 ].…”

Schwannoma of the Tongue: Ultrasonography

“…According to Kang et al (2007), neurilemmomas (i.e., schwannomas) may originate from any peripheral, cranial or autonomic nerves of the body (except of the olfactory and the optic nerves). 9 Schwannomas reported in pancreas 10 , kidneys 11 , hands 12 , thumbs 13 , floor of the mouth 14,15 , soft palate 16 , maxillary alveolus 17 , tongue 4,18−19 , etc. Pfeifle et al (2021) indicate that total of 25 percent of neurilemmomas occur in the head and neck area, but only 1 percent are intraorally located.…”