A 40-year-old male presented with 10-day history of anal pain, purulent discharge and burning sensation after defecation. According to the patient’s history, no comorbidities were present. On clinical examination of the anal and perianal area, a protruding mass with a maximum diameter of 7 mm was found at 6 o’clock in the lithotomy position. There was no evidence of local inflammation (Fig. 1).
Figure 1 Presence of an area with unusual aspect, at 6 o’clock in the lithotomy position
A 3-dimensional endoanal ultrasound (Hawk type 2050; Bruel and Kjaer Medical, Naerum, Denmark) was performed. Endoanal ultrasound did not reveal any anal/perianal abscess, but only a low posterior fistula-in-ano. The patient was also examined under general anesthesia (EUA). A probe proved the presence of a small internal haemorrhoid inside the fistula (Fig. 2A, B). The entrapped hemorrhoid was freed (Fig. 2C). The canal of the fistula was laid open lengthwise while the previously entrapped hemorrhoid was ligated and resected. Pathology confirmed the histological nature of the resected hemorrhoid. After EUA, all symptoms were resolved.
Figure 2 (A) Metallic probe through the canal of the anal fistula. (B) Presence of a small internal hemorrhoid inside the fistula. (C) The entrapped hemorrhoid was freed
The incidence of hemorrhoids in the general population ranges between 4.4% and 36.4% [1], although it is difficult to estimate their prevalence with precision [2]. Fistula-in-ano is also a quite frequent condition [3]. This is the first case described in the literature of a hemorrhoid entrapped inside a fistula-in-ano.