PMC8088493_01
Clinical/radiologic findings at patient presentation. (a) Photograph showing a 4 x 3 cm subcutaneous mass in the left temporal area of the head (white asterisk) and a previous skin incision (white arrowheads). (b) Computed tomography imaging showing destruction of the left temporal bone and a partially calcified mass lesion. (c and d) T1-weighted contrast-enhanced magnetic resonance imaging showing an enhancing mass with intracranial and extracranial cystic components.
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F1
She was found to have a 4 x 3 cm subcutaneous mass in the left temporal area of the head [Figure 1a]. Computed tomography (CT) imaging showed destruction of the left temporal bone and a partially calcified mass lesion [Figure 1b]. T1-weighted contrast-enhanced magnetic resonance imaging (MRI) showed an enhancing mass with intracranial and extracranial cystic components (5 cm and 3 cm in diameter, respectively) [Figures 1c and  d]. The scar of the previous operation [Figure 1a] was reincised, preserving a frontal branch of the superficial temporal artery.
Operative photographs. (a) Photograph showing that the skin and the temporal muscle covering the subcutaneous mass were left on the tumor side (white asterisk), and the skin flap was flipped. An artificial bone constructed in the previous surgery existed on the vertex side of the tumor (white arrow). A continuous narrow craniectomy was performed surrounding the tumor and the artificial bone (white arrowheads), and a dural incision was made using the space created by this narrow craniectomy. (b) Photograph showing the specimen obtained by en bloc resection of the tumor with adjacent skin (white asterisk), temporal muscle and extracranial lesion (white square), temporal bone (white arrows), dura mater, and intracranial lesion (white circle).
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F2
The surrounding skin flap was then flipped, and artificial bone constructed during the previous surgery was observed on the vertex side of the tumor [Figure 2a]. Subsequently, a continuous narrow craniectomy approximately 1 cm in width was performed surrounding the tumor and the artificial bone [Figure 2a]. A dural incision surrounding the tumor and the previous artificial bone were made using the space created by the narrow craniectomy [Figure 2a]. Subsequently, en bloc resection of the tumor with adjacent skin, temporal muscle, skull, dura mater, and a thin slice of the temporal lobe cerebral cortex was achieved [Figure 2b].
Illustration of the operative procedure. (a) Illustration showing intraoperative tissue expansion of the adjacent scalp using a 30 ml balloon in a 20-French Foley catheter after a small skin incision. The Foley catheter was inserted into the subcutaneous pocket, and the balloon was inflated with 30 ml of saline for 5 min and then deflated for 3 min. (b) Illustration showing intraoperative tissue expansion of the scalp on the parietal side with two Foley catheters. Repeated expansions were performed until sufficient expansion for a primary closure was achieved. (c) Illustration showing that the local rotation skin flap was created on the dorsal side of the skin defect. (d) Illustration showing that the skin defect was covered with this rotation skin flap and the expanded surrounding scalp, and a primary closure of the skin of the head was achieved. Thin black arrows show the skin incisions. Thick black arrows show the order of the procedures. Red arrows show the direction of the skin rotation.
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F3
After repeated intraoperative tissue expansion of the adjacent scalp using a 30 ml balloon in a 20-French Foley catheter [Figures 3a and b], a local rotation skin flap was created on the dorsal side of the skin defect [Figures 3c and  d].
Postoperative photographs and computed tomography imaging. (a) Photograph showing the surgical head wound on postoperative day 1. (b) Photograph showing the condition of the surgical head wound on postoperative day 90. (c) Postoperative computed tomography imaging showing the temporal bone defect adequately reconstructed with artificial bone.
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F4
The skin defect was covered with this rotation skin flap and the expanded surrounding scalp, and a primary closure of the skin of the head was achieved [Figure 4a]. The temporal bone defect was shown to be adequately reconstructed with artificial bone on postoperative CT imaging [Figure 4c]. The condition of the skin of the temporal region remained excellent without any signs of infection [Figure 4b], and no recurrence was found on follow-up MRI at 1 year after surgery [Figure 5c and d].
Postoperative magnetic resonance imaging. (a and b) Postoperative T1-weighted contrast-enhanced magnetic resonance imaging showing no residual tumor. (c and d) T1-weighted contrast-enhanced magnetic resonance imaging at 1 year after surgery showing no recurrence of the tumor.
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F5
No residual tumor was identified on postoperative T1-weighted contrast-enhanced MRI [Figures 5a and b]. The condition of the skin of the temporal region remained excellent without any signs of infection [Figure 4b], and no recurrence was found on follow-up MRI at 1 year after surgery [Figure 5c and d].
Micro-photographs of the specimens after hematoxylin and eosin staining. (a) The tumor was comprised atypical spindle cell components with focal cartilaginous differentiation. (b) Nuclear atypia and mitosis were occasionally seen.
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F6
Histological analysis revealed that the tumor was comprised atypical spindle cell components with focal cartilaginous differentiation [Figures 6a and b].