In humans
In humans, enteroliths are rare and may be difficult to distinguish from gall stones. Their chemical composition is diverse, and rarely can a nidus be found. A differential diagnosis of an enterolith requires the enterolith, a normal gallbladder, and a diverticulum.An enterolith typically forms within a diverticulum. An enterolith formed in a Meckels diverticulum sometimes is known as a Meckels enterolith. Improper use of magnesium oxide as a long-term laxative has been reported to cause enteroliths and/or medication bezoars.Most enteroliths are not apparent and cause no complications. However, any complications that do occur are likely to be severe. Of these, bowel obstruction is most common, followed by ileus and perforation. Bowel obstruction and ileus typically occur when a large enterolith is expelled from a diverticulum into the lumen. Perforation typically occurs within the diverticulum.On plain X-rays,the visibility of the enterolith depends on its calcium content. Calcium-rich stones usually demonstrate a radiodense rim and a relatively radioluscent core. Choleic acid stones are almost always radiolucent. They sometimes can be visualized on CT scans without contrast;  presence of contrast in the lumen may reveal the enterolith as a void. Most often, they are visualized using ultrasound. Although recent surveys of enterolith composition are lacking, one early review notes struvite (as in equines), calcium phosphate, and calcium carbonate and reports choleic acid. Deoxycholic acid and cholic acid have also been reported. Treatment
In simple cases of obstruction, where there are no complications, a variety of non-surgical and surgical techniques are used to remove the enterolith.
Bizarre parosteal osteochondromatous proliferation (BPOP), also known as Noras lesion, is a type of non-cancerous bone tumor belonging to the group of cartilage tumors. It is generally seen in the tubular bones of the hands and feet, where it presents with a rapidly enlarging painless lump in a finger or toe.It is composed of bone, cartilage and spindle cells. Some people report previous trauma.Diagnosis is by medical imaging. Treatment is by surgical excision. Up to 50% recur after surgery.It is rare, and occurs more often in the 20s and 30s. Combined with subungal exostosis, it accounts for less than 5% of cartilage tumors. Males and females are affected equally. The condition was first described by Frederick E. Nora in 1983. Signs and symptoms
BPOP generally presents with a 1–3 cm painless lump in a finger or more frequently a toe. Growth can be rapid. Mechanism
It is composed of bone, cartilage and spindle cells. A small number of people have reported previous trauma. Diagnosis
Medical imaging usually shows a well-defined wide-based bony growth on the surface of bone. Differential diagnosis
BPOP is distinct from subungal exostosis. Conditions that may appear similar to BPOP include: myositis ossficans, ostechondroma, surface osteosarcoma and granulomatous infection. Treatment
Treatment is by surgical excision. Outcomes
Up to 50% recur after surgery. Epidemiology
BPOP is rare. It is most often seen in people in their 20s and 30s. Combined with subungal exostosis, it accounts for less than 5% of cartilage tumors. Males and females are affected equally.