case_images: PMC10561767_01
case_images: Two-dimensional Color Doppler images of the lesion in the right lower abdomen and spleen obtained by transabdominal ultrasound. (A) Longitudinal view of the transabdominal ultrasound scan of the right lower abdomen, showing a mixed cystic and solid echo. The solid part (asterisk) was eccentric, most of the surrounding tissue was cystic, and a radial stripe light band was seen in the dark area connected to the solid part. (B) Color Doppler of the mass showed minimal linear blood flow in the solid part; heterogeneous echogenicity was observed in the right adnexa, mainly anechoic around some hyperechoic echogenicity in the center. (C) Transabdominal ultrasound of the spleen showing a mixed cystic and solid mass ( ) in the left hypochondrium, with irregular dark liquefied areas septate (left-right diameter of the mass: 7.52 cm). (D) Color Doppler image showing sparse blood flow in the solid part and no significant blood flow distribution in the cystic part.
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case_images: f1
case_images: Ultrasound of the lower abdomen revealed a mixed, and mainly cystic, mass with heterogeneous, measuring 6.5 cm x 4.2 cm at the right end and increased echogenicity in the center (4.5 cm x 2.1 cm) (Figure 1A). Color Doppler flow imaging (CDFI) revealed minimal flow in the center with a resistance index of 0.56 (Figure 1B). There was an incomplete splenic capsule with a mixed echo (size: 7.0 cm x 5.7 cm x 7.5 cm), with irregular morphology and an ill-defined border, obscuring differentiation from the normal splenic tissue (Figure 1C). However, CDFI showed little flow in the mixed echo area, except in the anechoic part (Figure 1D).
case_images: CEUS shows a lesion in the right lower abdomen and spleen. (A) In the transabdominal contrast-enhanced ultrasound examination, the solid capsular part of the mass in the right lower abdomen began to perfuse at 11 s (yellow arrow). (B) Isoenhancement is seen in the center (yellow arrow), and no contrast perfusion is observed in the cystic portion. (C) During the transabdominal contrast-enhanced ultrasound examination, the mixed mass of cystic and solid capsulated in the spleen began to perfuse at 14 s (yellow arrow). The contrast agent was unevenly distributed, with visible perfusion in the solid part but not in the cystic part. (D) The contrast agent entered the solid part (yellow arrow), which was isoenhanced, and the enhancement subsided at 37 s, which was earlier than that of the normal spleen tissue.
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case_images: To define the microvasculature of the mass, CEUS was performed, in which the agent was perfused within 11 s in the solid part of the mass in the right lower abdominal region (Figure 2A). The signal was equal to that of the intraperitoneal intestinal tract and regressed simultaneously but without any contrast agent perfusion in the anechoic part (Figure 2B). In the CEUS of the spleen, the solid part began to enhance at 14 s, and the contrast agent perfused with equal enhancement; the regression began at 37 s, which was earlier than that for the normal splenic tissue (Figures 2C, D).
case_images: Transvaginal ultrasound images of the uterus and bilateral adnexa of the patient. (A, C) Atrophic right and left ovaries can be visualized. (B) TVU image revealing an atrophic uterus without intimal thickening.
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case_images: f3
case_images: Based on the preliminary findings of a mass in the right lower abdomen of a female patient, a transvaginal ultrasound scan was performed to visualize the uterus and bilateral adnexa, which revealed an atrophied uterus without intimal thickening (Figure 3B), and both ovaries could be visualized (Figures 3A, C).
case_images: MRI and CT findings of the lesion in the right lower abdomen and spleen. (A, B) Axial view of the abdominal magnetic resonance scan revealed a slightly short T2 signal, a heterogeneous high signal in the diffusion-weighted image, and high signal intensity in the solid part (white arrow). (C) Axial view of contrast-enhanced computed tomography showing a multilocular cystic focus at the lateral splenic border (white arrow), which showed no significant enhancement after intracystic contrast perfusion, and intensity enhancement of the cyst wall after contrast perfusion. (D) Axial view of contrast-enhanced computed tomography revealed a mixed mass in the right lower abdomen, with significant enhancement in the central solid part.
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case_images: T2WI and a heterogeneous high signal on diffusion-weighted imaging (Figures 4A, B). The contrast-enhanced CT scan revealed that the solid part of the mass was significantly enhanced, and the periphery was connected to the omentum (Figure 4D), suggestive of pelvic inclusion effusion or a teratoma. The contrast-enhanced CT scan demonstrated a multilocular cystic focus at the lateral splenic border, which showed no significant enhancement in the intracystic region or cystic wall after contrast addition (Figure 4C). These findings indicated a diagnosis of LAMN.
case_images: Intraoperative view during exploratory laparoscopy and microscopic histopathological examination of lesions. Intraoperative view during exploratory laparoscopy revealed a yellow cystic mass in (A) the appendix region, with a milky white flocculent light band (red arrow) in the cyst. (B) Intraoperative view during exploratory laparoscopy revealing multiple yellow vesicular nodules (black arrow) in the peritoneum. (C) Hematoxylin and eosin (HE) staining of a low-grade mucinous tumor of the spleen, involving both the parenchyma and exterior of the splenic capsule and low-grade mucinous epithelial cells in the mucus lake. Original magnification: x10.
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case_images: f5
case_images: Eventually, the patient was prepared for laparoscopic exploratory surgery, which revealed a yellow-colored 7.0 cm cystic mass in the right lower abdomen (Figure 5A). Multiple yellow vesicular nodules were found in the peritoneum (Figure 5B), and histopathological examination of the biopsy specimen revealed a low-grade mucinous tumor in the appendix, involving the entire appendix and surrounding fat tissue (Figure 5C), along with invasion of the spleen and peritoneum.