PMC9909008_01
Intra-operative findings of the patient's first operation in our hospital. (a) The intraoperative photograph of the mass in the left hand of the patient. (b) The close-up detailed photograph of the mass in the left forearm shows the petroleum-like exudate. (c) The overall photographs of the mass in the left forearm of the patient. (d) The representative HE staining image of the resected tumor. (e) The representative Ki67 immunohistochemical staining image of the resected tumor. (f) The representative S100 immunohistochemical staining image of the resected tumor. Scar bar, 100 mum.
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F1
A spindle-shaped enlarged mass was found in the thenar region of the left hand, which was completely black and connected with the digital nerve (Figure 1a). After cutting open the mass, melanotic nerve fibers and black tumor-like hyperplasia were found, accompanied by black petroleum-like exudate (Figures 1b, c). Postoperative pathological confirmed MS and it was pathologically manifested as massive melanin deposition in tumor cells, and immunohistochemical staining suggested S100 and Ki67-positive, indicating that this tumor has a potential malignant tendency (Figures 1d-f).
The preoperative examination of the patient's second operation in our hospital. (a) The photograph of the patient trying to abduct his bilateral shoulders. (b) The photograph of the patient trying to flex his bilateral elbows. (c) The photograph of the patient trying to extend his bilateral fingers. (d) The photograph of the patient trying to flex his bilateral fingers. (e) The radiological image of the patient's chest. (f) The representative CT images of the patient's chest. (g) The bone scan images of the patient.
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F2
The patient's muscle strength of left wrist flexion, forearm pronation, finger extension, and intrinsic hand muscles was grade 0, and that of left finger flexion, wrist extension, forearm supination, elbow flexion, elbow extension, shoulder abduction, and adduction was grade 3 (Figures 2a-d). Chest X-ray and CT showed multiple quasi-circular negative lesions in both lungs, which were considered metastatic lesions (Figures 2e, f), while the patient did not complain of dry cough or hemoptysis. Bone scanning suggested metastatic lesions in the left humeral head and left eighth rib (Figure 2g).
The intra-operative photographs of the patient's second operation in our hospital. (a) The overall photograph of the mass in the patient's left arm. (b) The intraoperative photograph of the mass in trunks of the brachial plexus. (c) The close-up detail photograph of the black changed the nerves of the patient. (d) The close-up detail photograph of the black changed nerve shows the change of the never fibers intra epineurium. (e) The representative HE staining image of the resected tumor. (f) The representative Ki67 immunohistochemical staining image of the resected tumor. Scar bar, 100 mum.
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F3
During the surgery, it was found that from the clavicle to the elbow, the median nerve was completely melanotic, and the ulnar, radial, and musculocutaneous nerves were partially melanotic (Figures 3a, c). Exploration of the roots and trunks of the brachial plexus revealed that the upper, middle, and lower trunks of the brachial plexus were completely melanotic, but the suprascapular nerve was not melanotic (Figure 3b). All these phenomena suggest the growth pattern of the tumor spreading along the nerve fibers (Figure 3d). The Ki67 immunohistochemical staining was positive, which was consistent with the previous pathological results (Figures 3e, f).