PMC6768671_01
Mucinous adenocarcinoma arising from fistula-in-ano in a 54-year-old male (case 1).. (a) EAUS showing irregular, multiloculated complex echoic mass located in the posterior ischiorectal fossa. The mass consists of multiple hypoechoic locules of various sizes, thin septations with a latticed appearance, and a variable amount of isoechoic solid components (arrowhead). The mass exhibits communication with a trans-sphincteric fistula with an internal opening at 6 o'clock (arrow).. (b) Histological findings of endosonography-guided biopsy (hematoxylin-eosin stain, x40 magnification) showing mucinous adenocarcinoma.. (c) T2-weighted MRI showing a markedly hyperintense heterogeneous mass located in the posterior ischiorectal fossa.. (d) Macroscopic images of a surgical specimen depicting a multiseptated tumor with multiple mucous locules of various sizes.
2432-3853-1-0100-g001.jpg
PMC6768671_01_2432-3853-1-0100-g001.jpg
g001
Tokyo, Japan) real-time system with a linear rectal probe with a 7.5-MHz transducer, and it revealed an irregular, multiloculated complex echoic mass with posterior enhancement and abrupt interface, 3.5x3.5 cm in size, located in the posterior ischiorectal fossa (Figure 1a). Sonography-guided biopsy from the multiloculated lesion taken under local anesthesia revealed mucinous adenocarcinoma (Figure 1b). Magnetic resonance imaging (MRI) revealed markedly hyperintense heterogeneous content with enhancing solid components, also suggesting mucinous adenocarcinoma, and showed no regional lymphadenopathy or distant metastases (Figure 1c). Histological examination of the surgical specimen confirmed well-differentiated adenocarcinoma with mucin production (Figure 1d).
PMC6768671_02
Mucinous adenocarcinoma arising from fistula-in-ano in a 48-year-old male (case 2).. (a) EAUS showing trans-sphincteric fistula with an internal opening at 6 o'clock (arrow) and a multiloculated complex echoic mass with isoechoic solid components (arrowhead) located in the posterior ischioanal fossa.. (b) Histological findings of endosonography-guided biopsy (hematoxylin-eosin stain, x40 magnification) showing mucinous adenocarcinoma.
2432-3853-1-0100-g002.jpg
PMC6768671_02_2432-3853-1-0100-g002.jpg
g002
EAUS revealed a trans-sphincteric fistula with an internal opening at 6 o'clock and a multiloculated complex echoic mass, 3x3 cm in size, with isoechoic solid components in the posterior ischioanal fossa (Figure 2a). Sonography-guided biopsy from the multiloculated lesion taken under spinal anesthesia revealed mucinous adenocarcinoma (Figure 2b).
PMC6768671_03
Mucinous adenocarcinoma arising from fistula-in-ano in a 59-year-old male (case 3).. (a) EAUS showing a trans-sphincteric fistula with an internal opening at 6 o'clock (arrow) and a multiloculated complex echoic mass with isoechoic solid components (arrowhead) located in the left posterior ischioanal fossa.. (b) Histological findings of endosonography-guided biopsy (hematoxylin-eosin stain, x40 magnification) showing mucinous adenocarcinoma.
2432-3853-1-0100-g003.jpg
PMC6768671_03_2432-3853-1-0100-g003.jpg
g003
EAUS revealed a trans-sphincteric fistula with an internal opening at 6 o'clock and a multiloculated complex echoic mass, 3x2 cm in size, with isoechoic solid components in the left posterior ischioanal fossa (Figure 3a). Sonography-guided biopsy from the multiloculated lesion taken under spinal anesthesia revealed mucinous adenocarcinoma (Figure 3b).