A 66-year-old man was referred to our department for screening
colonoscopy. He had no gastrointestinal symptoms. Barium enema revealed a
curiously elongated polypoid lesion, 12 cm in length, in the transverse
colon ([Fig. 1]).
Fig. 1 Barium enema showing a
curiously elongated polypoid lesion in the transverse colon.
Colonoscopy showed an elongated polyp in the transverse colon with a
4-cm long head ([Fig. 2 a]) and an 8-cm
long stalk ([Fig. 2 b]).
Fig. 2 Colonoscopy showing the
elongated polyp in the transverse colon: (a) the long
head; and (b) the elongated stalk.
As the reddish head of the lesion was clearly visualized after
spraying with indigo carmine ([Fig. 3]),
endoscopic polypectomy was carried out.
Fig. 3 Colonoscopy after
spraying with indigo carmine dye showing the reddish head of the elongated
polyp in the transverse colon.
The resected specimen was covered by wrinkled, normal mucosa, and
was 4 cm in length ([Fig. 4]).
Fig. 4 The 4-cm long resected
specimen was covered by wrinkled, normal mucosa.
Histopathological examination revealed edematous submucosa covered
by normal mucosa. The dense submucosal layer contained dilated vascular and
lymphatic elements ([Fig. 5]).
Fig. 5 Histopathological view
showing the polyp covered by normal mucosa and a dense submucosal layer with
dilated vascular and lymphatic elements.
A diagnosis of the so-called colonic muco-submucosal elongated polyp
was made.
Matake et al. [1] proposed the term
“colonic muco-submucosal elongated polyp” for colonic polyps
characterized by non-neoplastic submucosal tissue covered by normal mucosa.
These polyps have extremely long stalks [1]
[2]
[3]
[4]
[5]. The pathogenesis of colonic muco-submucosal elongated
polyps has been the subject of speculation. Since they are characterized by the
presence of edematous, loose connective tissue within the submucosal layer,
they may be submucosal elevations that have become elongated due to mechanical
irritation resulting from the continuous intestinal peristalsis.
Endoscopy_UCTN_Code_CCL_1AD_2AC
