Polypectomy of a colonic muco-submucosal elongated polyp

Table of Contents

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

References

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• 2 Matake H, Matsui T, Yao T. et al . Long pedunculated colonic polyp composed of mucosa and submucosa; proposal of a new entity, colonic muco-submucosal elongated polyp.  Dis Colon Rectum. 1998;  41 1557-1561
• 3 Hoshika K, Iida M, Matsumoto T. et al . Elongated non-neoplastic colonic polyp: endoscopic features.  Gastrointest Endosc. 1998;  47 413-416
• 4 Yamamoto T, Ishi T, Kawakami T. et al . Colonic muco-submucosal elongated polyp.  Gastrointest Endosc. 2004;  59 868
• 5 Takahashi M, Kubokawa M, Tanaka Y. et al . Endoscopic ultrasonography features of colonic muco-submucosal elongated polyp.  Endoscopy. 2002;  34 515