PMC10312018_01
Appearance of the right middle finger at the time of initial examination. A smooth erythematous nodule 7 mm in size was observed on the ulnar lateral nail fold. The nail is shifted to the radial side. The subcutaneous area under the nodule was indurated, swollen, and tender. (left) Dorsal side of the affected finger. (right) Palmar side of the affected finger.
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The subcutaneous area of the nodule was tender around the lesion with induration, with his nail shifted to the radial side (Figure 1).
Ultrasound findings. B-mode images revealed a well-defined hypoechoic region seen protruding from the subcutis to the outside of the body. Color doppler images showed pulsatile vascular inflow from deep within the lesion (arrowhead).
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Ultrasonography revealed a borderline clear hypoechoic area extending continuously from the nodule to the subcutis of the fingertip (Figure 2).
Magnetic resonance imaging findings. An iso-intensity in T1 and high-intensity in T2 weighted images lesion was observed protruding subcutaneously to the body surface on the ulnar aspect of the distal phalanx (arrowhead).
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Furthermore, magnetic resonance imaging (MRI) showed a weighted images lesion of continuous iso-intensity in T1 and high-intensity in T2 on the ulnar aspect of the distal phalanx from subcutaneous through to outside the body (Figure 3).
Intraoperative findings. (a) Intraoperative Photograph. A terminal branch of the digital artery flowed into the deep part of the lesion (arrowhead). (b) Photograph of the resected lesion. The lesion was hourglass-shaped, separated by the skin.
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The lesion was hourglass-shaped, divided into internal and external parts by the skin, and was found to be in continuity with the terminal branches of the finger arteries in the deeper region of the lesion (Figure 4a, b).
Histopathological findings. Hematoxylin-eosin stained images at 40x magnification. Scale bar = 500 microm. (a) Pathological findings for the lesion. The three-layered structure of the arterial wall was disrupted, consistent with the finding of a pseudoaneurysm. (b) Pathological findings of one region of the lesion. Capillary dilation and edematous stromal hyperplasia were observed, which were characteristic of pyogenic granuloma.
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Histopathologic examination revealed that the lesion had resulted in loss of the three-layer structure of the arterial wall and as such was diagnosed as a pseudoaneurysm (Figure 5a). Furthermore, some regions of the lesion also showed dilated capillaries and edematous stromal growth with features of PG (Figure 5b).
Appearance 6 months after surgery. No recurrence of lesions was noted, and finger morphology and nail shift improved.
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His pain resolved quickly postoperatively, with no recurrence at 6 months, and his finger morphology and nail shift improved (Figure 6).