lNTRODUCTlON

Heterotopic ossification(HO)is a rare clinical phenomenon that refers to bone formation in nonossifying tissues.This is a unique phenomenon that has rarely been reported following abdominal surgery.HO of an incisional scar was first described by Askanazy in 1901 as a subset of myositis ossificans traumatica[1,2].Since then,more than 100 cases have been reported worldwide[2-6].These numbers are probably an underestimate of the actual incidence,because these ossifications are usually asymptomatic[3].HO has been described as a benign postoperative complication in most studies.

CASE PRESENTATlON

Chief complaints

The first patient was a 62-year-old man,he underwent radical gastrectomy(Billroth I anastomosis)with a midline abdominal incision.Postoperatively,the patient experienced pain below the incisional area.

A 57-year-old man also underwent distal gastroscopy(Billroth I anastomosis)due to gastric cancer with a midline abdominal incision.The patient had no other comorbidities.

History of present illness

The two patients underwent distal gastroscopy(Billroth I anastomosis)because of gastric cancer.

History of past illness

The patient had a history of coronary stent implantation performed 3 mo ago.

The patients had no significant past illness.

Personal and family history

The patients had no significant personal and family history.

The King had a walnut shell ready, and the trial began; but not one of the dogs the two eldest23 sons had brought with them would in the least fit into the shell

I finally remembered to call about the portrait framing and thanked God my father had gotten a chance to see the pictures before he died. I was surprised when the shopkeeper told me my father had visited the shop, paid for the framing and had them gift?wrapped. In all our grief, I had no longer planned to give the portraits to my mother.

Physical examination

Upon palpation,the incisional area was hard and firm.

There were no signs of anastomotic leakage,and the wound healed.

Imaging examinations

Computed tomography(CT)2 wk postoperatively showed no obvious abnormality(Figure 1A),but the 6-wk CT showed calcification beneath the incision(Figure 1B-D).

In the 4-mo follow-up CT scan,calcified tissue was noted under the upper abdominal incision,extending from the immediate subxiphoid region to the umbilical region(Figure 1E-G).

FlNAL DlAGNOSlS

The main symptoms of HO include local pain and swelling[7].In suspicious cases,CT or magnetic resonance imaging should be performed for diagnosis[2].It is also important to exclude other postoperative complications,such as anastomotic leakage and tumor recurrence.In patients with intractable abdominal pain,conservative therapy,such as analgesic administration,parenteral transfusion,and physical therapy,should be initially performed.If conservative therapy fails,then complete excision of the lesion should be considered.Asymptomatic patients need no treatment apart from observation.The first patient in our experience had sustained abdominal pain postoperatively and was readmitted to the hospital twice.After 1 mo of conservative therapy,pain was immediately relieved before surgery was considered.

TREATMENT

The patient of case 1 refused reoperation,and after conservative therapy(non-steroidal anti-inflammatory drugs),the pain was gradually relieved after 2 wk.

OUTCOME AND FOLLOW-UP

At a 1-year follow-up,the patients of case 1 had no signs of recurrence.

DlSCUSSlON

The following common features of ectopic ossification have been summarized in documented cases:(1)Male patients are more susceptible to ectopic ossification,and the male-to-female ratio is as high as 10:1[7];(2)this pathology has mostly been reported in vertical scars;(3)the ectopic bone is generally formulated within the first year postoperatively;and(4)all cases in the literature occurred during primary healing,and neither wound complications nor changes in serum ion levels were noted.Both our cases fit all of these features.Moreover,the newly formed bone was detected in the first case 6 wk postoperatively,which is sooner than the earliest ectopic abdominal incision ossifications reported in the literature(2 mo)[1].Our findings suggest that HO beneath the abdominal incision might form at approximately 1 mo postoperatively.

While no certain theory has yet been confirmed regarding etiology,several mechanisms have been studied to help explain this pathological process.Injury or,more specifically,surgical incision is considered a necessary trigger[4].Three requisite components are involved in the pathogenesis[7]:(1)Inductive signaling pathways are activated by a stimulation factor released from the site of injury.These factors,including bone morphogenic proteins,have been implicated as potential signaling vehicles[8];(2)then,inducible mesenchymal stem cells,which are located at the injury site,differentiate into osteoblasts or chondroblasts after receiving these signals.This process has been described as osteogenic induction[1,4];and(3)a heterotopic environment conducive to osteogenesis must exist.HO of the abdominal wall is a subtype of myositis ossificans traumatica.Pieces of the periosteum or perichondrium of the xiphisternum or symphysis pubis may“plant”into the incision wound during the operation and then grow into bone in the scar[1,4].During laparotomy,we extended the incision to the xiphisternum in both cases,which can be regarded as proof of this theory to some extent.

Tam

[9]recently reported a case of HO in a patient after hernia repair.In the ectopically formed bone,they found an acellular dermal matrix that had been placed in the primary incision.In our case,we placed a sodium hyaluronate-based bioresorbable membrane(Seprafilm)under the peritoneum of each patient to prevent adhesion.It has been postulated that this type of anti-adhesion agent can cause inflammatory reactions as a severe postoperative complication[10-12].Whether Seprafilm was the culprit in our case needs to be further investigated.

It seems to me now that he sighed and that I tittered to hide my embarrassment8 and told him that some girls thought of marrying rich men, and one I knew of thought only of her hair; she washed it every night and measured how much it grew in a week. He looked at his watch and inevitably9 he had to go.

The patients were diagnosed with ossification beneath the upper abdominal incision.

CONCLUSlON

Non-steroidal anti-inflammatory drug therapy,radiotherapy,and diphosphate(ethindronate disodium)administration have been proposed to decrease heterotopic bone formation[1].However,the routine application of these methods is controversial and unnecessary.

FOOTNOTES

Zhang X,Dai Y and Wang YL were the patients’ surgeons,reviewed the literature and drafted the manuscript;Xia PT and Ma YC contributed to the manuscript drafting;Ma YC created figures and interpreted the imaging findings;all authors approved the final version of the manuscript.

the Clinical and Practical New Technology Development Fund of Qilu Hospital of Shandong University.

This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers.It is distributed in accordance with the Creative Commons Attribution NonCommercial(CC BYNC 4.0)license,which permits others to distribute,remix,adapt,build upon this work non-commercially,and license their derivative works on different terms,provided the original work is properly cited and the use is noncommercial.See: https://creativecommons.org/Licenses/by-nc/4.0/

Then my father poked12 his chopsticks just below the fish eye and plucked out the soft meat. Amy, your favorite, he said, offering me the tender fish cheek. I wanted to disappear. At the end of the meal my father leaned back to and belched13 loudly, thanking my mother for her fine cooking. It s a polite Chinese custom to show you are satisfied, explained my father to our astonished guests. Robert was looking down at his plate with a reddened face. The minister managed to muster14 up a quiet burp. I was stunned15 into silence for the rest of the night.

The authors have read the CARE Checklist(2016),and the manuscript was prepared and revised according to the CARE Checklist(2016).

The authors declare that they have no conflict of interest.

It was 1997, in Chittagong, Bangladesh（）, me and my family have just moved to a new apartment in a new area. So, after few weeks have passed, I started going back to school, since it was during Ramadan we moved. Well, I made some new friends in the neighborhood. This girl who was always hanging out with, her name was Ivy2.

Informed written consent was obtained from the patients for the publication of this report and any accompanying images.

China

Then the marriage took place, in the presence of Girouette, whom they had the greatest trouble to find, and who was much astonished to discover how much business had been got through in her absence

Xiang Zhang 0000-0001-7417-6082;Ping-Tian Xia 0000-0001-8032-8871;Yan-Chao Ma 0000-0002-9157-4063;Yong Dai 0000-0001-6163-8022;Yan-Lei Wang 0000-0002-4227-0274.

When the kids came in, he took them for walks along the pier21 near their office. Often she went along and watched Eric, who was becoming a master of sign language, talk and laugh with her boys as no one else had before.

Chen YL

I didn t stay lost forever. I found something that I wasn t looking for: a voice through writing. Only later did I understand that this would be a bridge to understanding my father in another way. A way that led me to connect to a passion I didn t realize we both shared.

A

Chen YL

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