PMC8456086_01
The lesions indicated by arrows at different time points. (A1, A2) Lesions were observed before surgery in the CT images in April 2019. (B1, B2) Images after surgery in May 2019. (C1, C2) Partial remission of the lesions after two cycles of CHOP. (D1, D2) New lesions can be seen in March 2020 after a PFS of 2 months. (E1, E2) The lesions were expanded after two cycles of ABVD chemotherapy. (F1, F2) The lesions shrunk after 3 cycles of sintilimab and lenvatinib. (G1, G2) Partial remission of the lesions were shown after 6 cycles.
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An abdominal computed tomography (CT) scan showed an 8.9 x5.7 cm solid mass in the left abdominal cavity (Figure 1A1), and many soft tissue density shadows were observed in the abdominal cavity, especially in the rectovesical pouch (Figure 1A2). The CT after surgery showed multiple nodules in the mesentery, pelvic cavity and rectovesical pouch, and the largest nodule was 2.5*2.2 cm located in the rectovesical pouch (Figure 1B). Following two cycles of CHOP chemotherapy, partial response (PR) was achieved based on the CT evaluation, and the largest lesion in the rectovesical pouch was 1.7*1.4 cm. (Figure 1C). The mass in the left midabdomen was 2.7 cm*2.8 cm (Figure 1D1), and the largest lesion in the rectovesical pouch was 2.0 cm*1.6 cm (Figure 1D2). However, the mass in the left midabdomen enlarged to 3.2 cm*3.0 cm, and the lesion in the rectovesical pouch increased to 2.0 cm*1.9 cm in June 2020 (Figure 1E). After three cycles of treatment, the lesions size decreased (Figure 1F). December 2020 (Figure 1G2). During the course of sintilimab combined with lenvatinib, the patients presented good tolerance to the combined approach.
(A, B) Hematoxylin-eosin staining of primary tumors: small intestinal spindle cell tumors. (C) Immunohistochemical staining for CD21 (C1), CD23 (C2) and CD35 (C3).
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Partial intestinal resection was performed with a mechanical side-to-side anastomosis and negative margins were confirmed intraoperatively in April 2019.The pathological result after the operation was as follows: small intestinal spindle cell tumor (Figures 2A, B ). Immunohistochemistry (Figure 2C): tumor cells CD21 (+, partial), CD23 (+ partial), CD35 (weak positive), sstr-2 (+, partial), CD163 (+ partial), cd68/pgm-1 (+, focal area), HMB45 (-), PCK (-), ALK (-), LCA (-), EMA (-), STAT-6 (-), syn (-), TLE (-), DOG-1 (-), SDHB (without delated), CD117 (-), DES (-), CD34(-), SMA (-), S100 (-), Ki-67 (+, 10% - 20%), in situ hybridization EBER1/2 (-), PD-1 (-), and PD-L1 (+90%) (Figure 3).
Immunohistochemical staining of tumor cells for PD-LI (22C3) in our patient. PD-L1 expression was 90%.
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Immunohistochemistry (Figure 2C): tumor cells CD21 (+, partial), CD23 (+ partial), CD35 (weak positive), sstr-2 (+, partial), CD163 (+ partial), cd68/pgm-1 (+, focal area), HMB45 (-), PCK (-), ALK (-), LCA (-), EMA (-), STAT-6 (-), syn (-), TLE (-), DOG-1 (-), SDHB (without delated), CD117 (-), DES (-), CD34(-), SMA (-), S100 (-), Ki-67 (+, 10% - 20%), in situ hybridization EBER1/2 (-), PD-1 (-), and PD-L1 (+90%) (Figure 3).
PET/CT did not show focal hypermetabolism of those lesions corresponding to the nodules in CT.
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However, PET/CT did not show focal hypermetabolism of those lesions corresponding to the nodules in CT (Figure 4).
Timeline scheme of major clinical event of the patient since diagnosis.
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PFS was 7 months following sintilimab and lenvatinib (Figure 5).