Large malignant granular cell tumor with suprascapular nerve and brachial plexus invasion: A case report and literature review

Granular cell tumor of the brachial nerve in a dog: A case report

Here, we describe the first case of a granular cell tumor (GCT) derived from the brachial nerve. Eleven-year-old neutered female Chihuahua presented to the hospital with a bulge from the left neck to the axilla. The dog had a spherical subcutaneous mass on the cervical subcutis, and cytology hinted at adenocarcinoma or neuroendocrine tumor. However, the origin of the tumor remains unknown. During resection of the mass, bleeding was difficult to control owing to the high blood flow, and tumor removal was extremely difficult. The caudal aspect of the mass was attached to the brachial nerve and had to be removed, along with parts of the nerve fibers. The patient's postoperative course was fair, but it developed paralysis of the left thoracic limb. Pathology revealed that the mass was positive for S100 and vimentin, and GCT was diagnosed. Non-oral GCTs are extremely rare. The clinical diagnosis of GCT is difficult and is often confirmed histopathologically by excision. Although most cases of GCT are benign, they must be recognized as hemorrhagic, indistinct masses that mimic malignancy. Excision carries the risk of hemorrhage and damage to the surrounding tissues to secure margins.

Granular cell tumors of the urethra

Granular cell tumors (GCTs) are a rare type of mesenchymal tumors that are histologically derived by Schwann cells and rise within soft tissues such as skin and mucosal surfaces. Differentiation between benign and malignant GCTs is often difficult and relies on their biological behavior and metastatic potential. While there are no standard guidelines for management, upfront surgical resection, whenever feasible, is key as a definitive measure. Systemic therapy is often limited by poor chemosensitivity of these tumors; however, accumulating knowledge of their underlying genomic landscape has opened some opportunities for targeted approaches, for example, the vascular endothelial growth factor tyrosine kinase inhibitor pazopanib, which is already in clinical use for the treatment of many types of advanced soft tissue sarcomas.

Diffusion-weighted MR is useful to assess peripheral nerve invasion of soft tissue tumor

To investigate the feasibility of readout-segmented diffusion-weighted (rsDW) magnetic resonance (MR) in assessing nerve invasion of soft tissue tumor. Forty-four patients with soft tissue mass in upper leg suspected of nerve invasion underwent rsDW MR. Nerve invasion by tumor was rated by 2 radiologists, respectively. Sensitivity and specificity of rsDW MR in identifying nerve invasion were calculated, with operation findings as reference of standard. Apparent diffusion coefficient and fraction of anisotropy of nerve were obtained using DW MR, and then were compared between invaded nerves and noninvasion cases. Inter-reader agreement in using rsDW MR to rate nerve invasion was excellent (kappa = 0.891 ± 0.043, P < 0.001). Sensitivity and specificity of rsDW MR in identifying nerve invasion were 89% and 88%, respectively. Apparent diffusion coefficient was significantly higher in invaded nerves versus normal nerves (1.45 ± 0.67 × 10-3 mm2/s vs 1.39 ± 0.46 × 10-3 mm2/s, P < 0.05). Fraction of anisotropy was significantly lower in invaded nerves versus normal nerves (0.22 ± 0.11 vs 0.37 ± 0.13, P < .05). Readout-segmented DW MR was feasible in assessing sciatic nerve invasion by soft tissue tumor in selected patients.

Long-term Improvements of Neuroplasty and Scalene Muscle Resection in LTN-injured Winged Scapula Patients

Injuries to the long thoracic nerve, which directly branches off of the C6, C7, and C8 brachial plexus nerve roots, can cause scapular winging and affect shoulder movements. Long thoracic nerve injuries resulting from accidents, violence, or overuse can be severe lesions requiring challenging surgeries. We evaluated the long-term functional outcomes of neuroplasty and the scalene muscle resection procedures in patients with long thoracic nerve injury and winging scapula.

Methods

All 15 patients who underwent scalene muscle resection with decompression and neurolysis of the long thoracic nerve in a single institution to treat winged scapula and limited shoulder movements between March 2007 and May 2020 with follow-up over 2 years were included in the study.

Results

Shoulder abduction and arm flexion improved significantly to 158 ± 52 degrees and 165 ± 53 degrees from a mean of 108 ± 54 degrees and 104 ± 52 degrees (P < 0.02) over 2 years after surgery (mean 3.4 years). Overall, there was a significant reduction in the scapular winging, as assessed by estimating the decrease in the angle between the scapular plane and the posterior chest wall. The extent of the score greatly improved post-surgically from a mean of 1.2 ± 0.4 to 3.5 ± 0.9 (range 1-4; 1-severe, 2-moderate, 3-mild, and 4-minimal) (P < 0.01).

Conclusion

The improvement in shoulder movements and reduced scapular winging was significant and stable over 2 years of surgery in 81% of our study patients.