Intraabdominal Myositis Ossificans: A Report of 9 New Cases

"Heterotopic abdominal wall ossification: A case report" information

INTRODUCTION AND IMPORTANCE

Heterotopic ossification is forming a new bone in tissues that do not normally ossify. HO was first reported in 1901 by Askanazy and Lubarsh in a case report study. The range of HO is wide from minute foci to large clinically significant ossification. The incidence of HO in abdominal scars is extremely low.

CASE PRESENTATION

We present an 84-year-old man referred to our hospital after an unsuccessful elective colostomy reversal in a local hospital. The colostomy was made for fecal diversion after sigmoidectomy due to treatment of sigmoid volvulus about three months ago. The patient had a past medical history of hypertension for 8 years under treatment of amiloride.

CLINICAL DISCUSSION

In general appearance, the patient was not ill or toxic. Vital signs were normal. Postoperatively Patient did not defecate. In his physical examination was not found abdominal tenderness or rebound tenderness. The patient underwent laparotomy which revealed significant retroperitoneal adhesion and colostomy was reversed. Accidentally was found a dense structure with bone-like consistency in the abdominal wall close to the scar was resected. The specimen Pathologic examination showed metaplastic bone deposition with mature bone trabeculae and heterotopic ossification was confirmed.

CONCLUSION

We report a rare case of HO that was identified at the abdominal wall. Heterotopic ossification can lead to serious complications. However, in symptomatic patients, surgical excision is an acceptable treatment, unlike in asymptomatic patients.

Intra-abdominal myositis ossificans - a clinically challenging disease: A case report

BACKGROUND

Myositis ossificans (MO) is an uncommon disorder characterized by heterotopic ossification within soft tissues. Only a few cases of intra-abdominal MO (IMO) have been described in the literature. Histology could be difficult to understand and a wrong diagnosis could lead to an improper cure.

CASE SUMMARY

We herein report the case of IMO in a healthy 69-year-old man. The patient presented with an abdominal mass in the left lower quadrant. A computed tomography scan showed an inhomogeneous mass with multiple calcifications. The patient underwent radical excision of the mass. Histopathological findings were compatible with MO. Five months later the patient showed a recurrence causing hemorrhagic shock due to intractable intralesional bleeding. The patients eventually died within three months since recurrence.

CONCLUSION

The case described could be classified as post-traumatic MO that developed close to the previously fractured iliac bone. The subsequent surgical procedure was ineffective and the disease rapidly recurred. The misleading intraoperative diagnosis led to improper surgical treatment with a dramatic evolution.

ICAM-1-mediated osteoblast-T lymphocyte direct interaction increases mineralization through TGF-β1 suppression

Modulation of osteoblast functions by T lymphocytes is important in inflammation-associated mineralized tissue diseases. The study aimed to determine whether direct interaction between these two cell types affects osteoblast functions and mineralization. The results showed that direct contact between the two cell types was evident by scanning electron microscopy and transmission electron microscopy. Under osteogenic induction, higher hydroxyapatite precipitation was observed in cocultures with direct contact with T lymphocytes compared with that by osteoblasts cultured alone. Cocultures without direct cell contact caused a decrease in mineralization. Direct cell contact also upregulated intercellular adhesion molecule (ICAM)-1 and simultaneously downregulated transforming growth factor (TGF)-β1 in osteoblasts. However, the downregulation of TGF-β1 was reversed by ICAM-1 blocking. Exogenously added TGF-β1 in cocultures with direct cell contact suppressed mineralization. In conclusion, studies are consistent with ICAM-1-mediated direct contact between osteoblasts and T lymphocytes increasing mineralization via downregulation of TGF-β1 in osteoblasts in vitro. This suggests a possible unexpected, but crucial, role of T lymphocytes in enhancing matrix mineralization during the repair process in vivo. The study identifies ICAM-1/TGF-β1 as possible novel therapeutic targets for the treatment and prevention of inflammation-associated mineralized tissue diseases.

Bowel obstruction and perforation secondary to progressive heterotopic mesenteric ossificans

Heterotopic mesenteric ossification (HMO) is a rare condition which usually affects male patients. Its defining feature is hyperdense ossification in the mesentery, usually following surgery or trauma. Due to potentially serious complications that can arise from HMO, it is essential to recognize it in its nascent stages. In this case study, a 65-year-old male was imaged by CT scan serially over several years for recurrent bowel obstruction as a result of worsening HMO, providing new insight into the natural progression of this condition. Mechanical injury of the bowel eventually caused perforation and abscess formation.

Are open surgery and total resection good choices for traumatic myositis ossificans in children?

BACKGROUND

Traumatic myositis ossificans is a self-limited, non-neoplastic, ectopic bone formation in the soft tissues caused by trauma. Conservative treatment is the mainstay of management. However, open surgery and complete resection should be considered in patients with limited joint function and constant pain. Herein, we retrospectively analyzed the outcome of open surgical resection in children with myositis ossificans (MO).

METHODS

The data of patients diagnosed with MO between February 2010 and May 2019 were retrospectively analyzed. The clinical data included medical history, physical examination, and laboratory, imaging, and pathological findings. All patients underwent an open surgery and total resection. Radiography findings and joint function were evaluated. Patients with developing complications, such as recurrence and assessing joint function, were followed up. In total, 20 patients (sex, 15 male and 5 female patients; age, 8.1 ± 2.5 years) were included.

RESULTS

MO was located around the elbow, wrist, proximal humerus, and thigh in 13, one, one, and five patients, respectively. All patients were followed up for > 12 months. Two patients had partial recurrence after surgery. One patient with forearm MO had poor elbow function (Broberg-Morrey score of 70). Nineteen patients had good functional outcomes according to the Broberg-Morrey and Cooney methods.

CONCLUSION

Open surgical resection is an effective method for children with MO. The recurrence rate was low when the surgery was performed after the acute stage (1.5 months from disease presentation).

A case report and literature review of heterotopic mesenteric ossification

Introduction and importance

Heterotopic mesenteric ossification is a benign bony tissue growth in the mesentery that mostly follows repetitive or severe abdominal injuries leading to reactive bone formation in the mesentery. There are only 73 cases (51 publications) identified in the literature up to the beginning of 2020.

Case presentation

45-year-old Saudi male underwent multiple laparotomies to manage complicated appendicitis which ended with a diverting ileostomy and a colostomy as a mucus fistula. After 9 months, the patient was admitted to the General Surgery department in Al-Hada Armed Forces Hospital for an open ileostomy and colostomy reversal surgery where several irregular bone-like tissues of hard consistency and sharp edges with some spindle-shaped structures resembling needles were found in the mesentery of the small intestine and histopathology revealed of trabecular bone fragments confirming the diagnosis.

Clinical discussion

The majority of cases occur mid to late adulthood with a predilection in the male gender, and usually present with bowel obstruction or an enterocutaneous fistula. Although it has no malignant potential, it may cause severe bowel obstruction that can lead to mortality, it's a rare occurrence and, therefore, is difficult to diagnose among many common abdominal disturbances.

Conclusion

Here we report a rare case of heterotopic mesenteric ossification, which should be considered as one of the delayed complications of abdominal surgery or trauma. The time range of expecting the presentation of heterotopic mesenteric ossification following major abdominal trauma or surgery should be extended and continuously considered during differential diagnosis.

•

One of the delayed complications of abdominal surgery or trauma is Heterotopic mesenteric ossification.

•

Since 1983 there are only 73 cases of Heterotopic mesenteric ossification published to date.

•

Preoperative diagnosis of Heterotopic mesenteric ossification should be based mainly on the characteristic radiographic findings without relying on the levels of calcium or alkaline phosphatase.

•

The only way to reach the definitive diagnosis is through excision and histopathological analysis.

•

Heterotopic mesenteric ossification has no malignant potential, but it can cause severe bowel obstruction that can lead to mortality in already sick patients.

An unusual case of bowel obstruction in emergency surgery: The heterotopic mesenteric ossification

The heterotopic mesenteric ossification, also known as myositis ossificans, is a rare form of heterotopic ossification, a metaplastic phenomenon where new bone is formed in the mesenteric base, generally after abdominal trauma (surgical or other). The pathophysiology of heterotopic mesenteric ossification is unknown; clinical presentation is not specific, with vague abdominal symptoms, uncertain radiological findings, and often regular laboratory exams. No consensus exists on the best possible approach, although it might well be both medical and surgical. We reviewed the clinical history of a 28-year-old man with a recent motor vehicle accident who was admitted to our surgical unit with symptoms consistent with a small bowel obstruction; after surgery, a diagnosis of myositis ossificans was surprisingly made.

A case report of mesenteric heterotopic ossification: Histopathologic and genetic findings

Mesenteric heterotopic ossification (MHO) is very rare and occurs in mid- to late-adulthood, usually in the context of prior abdominal surgery. The mechanisms of MHO are unknown. Here we describe the case of a 72-year-old man with MHO. Standard histological staining revealed that MHO occurred through an endochondral process. By comparison to known mutations in genetic conditions of HO such as fibrodysplasia ossificans progressiva (FOP) and progressive osseous heteroplasia (POH), DNA sequencing analysis demonstrated the presence of a commonly occurring heterozygous synonymous polymorphism (c.690G>A; E230E) in the causative gene for FOP (ACVR1/ALK2). However, no frameshift, missense, or nonsense mutations in ACVR1, or in the causative gene for POH (GNAS), were found. Although genetic predisposition may play a role in MHO, our data suggest that mutations which occur in known hereditary conditions of HO are not the primary cause.

Mesenchymal Stem Cells as Endogenous Regulators of Inflammation

This chapter discusses the regulatory role of endogenous mesenchymal stem cells (MSC) during an inflammatory response. MSC are a heterogeneous population of multipotent cells that normally contribute towards tissue maintenance and repair but have garnered significant scientific interest for their potent immunomodulatory potential. It is through these physicochemical interactions that MSC are able to exert an anti-inflammatory response on neighbouring stromal and haematopoietic cells. However, the impact of the chronic inflammatory environment on MSC function remains to be determined. Understanding the relationship of MSC between resolution of inflammation and autoimmunity will both offer new insights in the use of MSC as a therapeutic, and also their involvement in the pathogenesis of inflammatory disorders.

Heterotopic mesenteric and abdominal wall ossification - Two case reports in one institution

•

Heterotopic ossification (HO) is related with the abnormal bone formation in tissues that normally do not ossify.

•

Heterotopic mesenteric ossification is a rare form of HO, characterized by the formation of an ossificant pseudotumor in the mesenteric base.

•

Pathophysiology of HO has been postulated to be due to osteoblastic metaplasia of multipotent mesenchymal cells in response to stimulus.

•

Prognosis of HO is generally good, so treatment should be conservative, avoiding surgery to prevent further ossification.

Introduction

Heterotopic ossification occurs when bone develops in tissues which usually don’t undergo ossification. Heterotopic mesenteric ossification, also known as intra-abdominal myositis ossificans, is a rare and benign form of ossification, usually related with previous abdominal surgery or trauma.

Presentation of cases

We report two cases of heterotopic ossification both after multiple abdominal surgeries, with intraoperative findings of mesenteric and abdominal wall ossification. Histopathology revealed metaplastic bone deposition, without evidence of atypia or malignancy.

Discussion

This rare entity shares clinical and pathological characteristics of myositis ossificans. It is important to consider the differential diagnosis with sarcomas. In the cases described, the patients were proposed for elective surgery and this pathology was as an incidental finding.

Conclusion

The simultaneous presence of mesenteric and abdominal wall ossification in both patients makes these cases even rarer.

Intra-abdominal myositis ossificans in an asymptomatic patient during closure of a Hartmann's colostomy

Intra-abdominal myositis ossificans, also known as heterotopic mesenteric ossification, defines the formation of bone-like lesions inside the abdominal cavity. It is a rare medical condition, usually following abdominal surgery or trauma. A 55-year-old male presented for closure of a Hartmann's colostomy, created 6 months ago because of sigmoid adenocarcinoma. Intraoperative findings consisted of an elongated bone-like lesion attached on the peritoneum and protruding inside the abdominal cavity, while two more stiff calcified nodules were found in the mesocolon. All lesions were excised. The presence of a hard consistency sigmoid stump led to cancelation of the operation. Heterotopous bone formation constitutes a challenging surgical condition, since its clinical presentation is innocuous and repetitive surgery acts a stimuli for additional bone creation. Computed tomography scan plays a major role in its diagnosis, while nonsteroidal anti-inflammatory drugs and cimetidine are helpful in preventing further recurrence of the disease.

Heterotopic Mesenteric Ossification after Blunt Abdominal Trauma and Multiple Surgical Operations

We present a case of a 26-year-old man with mesenteric heterotopic ossification following blunt abdominal trauma and multiple surgical operations. Computed tomography 10 months after the initial trauma demonstrated linear, branching opacities within the small bowel mesentery that had a cortical and trabecular structure indicative of mature bone. We found only 25 reports in the literature of small bowel mesentery heterotopic ossification. The significance of this non-neoplastic process is three-fold: (1) patients often present with bowel obstruction; (2) the process tends to worsen or reoccur after repeat laparotomy, and (3) rare forms of malignant neoplasms such as extraskeletal osteosarcoma may have a similar appearance.

Mesenteric calcification following abdominal stab wound

INTRODUCTION

Heterotopic ossification (HO) refers to the formation of bone in non-ossifying tissue. Heterotopic mesenteric ossification is a rare form of HO that is characterized by the formation of an ossifying pseudotumour at the base of the mesentery, usually following abdominal surgery.

PRESENTATION OF CASE

We describe a case of mesenteric HO in a young male who presented for elective ventral incisional hernia repair following a stab wound to the abdomen requiring exploratory laparotomy 21 months earlier. Preoperative workup was unremarkable, but a hard, bone-like lesion was noted to encircle the base of the mesentery upon entering the abdomen, consistent with HO. The lesion was excised with close margins, and his hernia was repaired without incident.

DISCUSSION

Traumatic HO describes the ossification of extra-skeletal tissue that specifically follows a traumatic event. It usually occurs adjacent to skeletal tissue, but has been occasionally described in the abdomen as well, usually in patients who suffer abdominal trauma. Overall the prognosis of HO is good, as it is considered a benign lesion with no malignant potential. However, the major morbidity associated with mesenteric HO is bowel obstruction.

CONCLUSION

The size, location, and symptoms related to our patient's mesenteric HO put him risk for obstruction in the future. As a result, the mass was surgically excised during his ventral hernia repair with good outcomes.

Heterotopic mesenteric ossification: report of a case and review of the literature

Heterotopic mesenteric ossification (HMO) is a distinct intra-abdominal ossifying pseudotumour that typically occurs in men, almost always after surgery or abdominal trauma, and frequently presents with symptoms of intestinal obstruction. We herein describe a case of HMO occurring in a 42-year-old Iranian man with a history of abdominal blunt trauma. He underwent partial small intestinal and its mesentery resection. The postoperative course was uneventful. Now he is in good condition after 6 months.

Bone in the belly: traumatic heterotopic mesenteric ossification

Heterotopic mesenteric ossification is an unusual but important complication in patients who sustain blunt and penetrating abdominal trauma. In this condition, bone formation occurs in the mesenteric and omental fat in response to injury and may result in serious complications such as bowel obstruction and fistula formation. Although a few case reports exist, the radiology literature on this topic is scant. Based on our experience, this entity is under-recognized on imaging studies and often results in diagnostic confusion due to its resemblance to other pathologies such as barium leak and extraskeletal bone-forming neoplasms. This review highlights the imaging features of heterotopic mesenteric ossification with an emphasis on computed tomographic findings. Radiologist awareness of this condition is crucial to avoid misdiagnosis as well as to direct appropriate and timely management.

Reactive bone lesions mimicking neoplasms

Reactive lesions of bone and soft tissue can appear alarming on histologic examination because they are often cellular and have atypical (activated) cytologic features, such as distinct nucleoli and mild hyperchromasia, and mitotic activity. Reactive lesions of bone and periosteum also produce bone and cartilage matrix, resulting in confusion with osteosarcoma or chondrosarcoma. Careful attention to key cytomorphological features such as the pattern of bone formation, uniform appearance of cells, and absence of atypical mitoses should help identify the reactive nature of a lesion. Correlation with clinical and radiological findings is also imperative to avoid misclassification of the tumor because reactive lesions often arise at sites where osteosarcoma and chondrosarcoma are rare (e.g., the hand) and lack aggressive radiological features. In this review we discuss reactive lesions of bone that are commonly confused with malignant neoplasms and that the practicing pathologist is likely to encounter at some point. Several of these lesions have had characteristic chromosomal translocations documented in recent years, but continue to be included as reactive lesions based on their overall clinicopathological features.

Cholecystitis and cholelithiasis associated with an intramural fasciitis-like proliferation and osseous metaplasia

Fasciitis-like proliferations are said to be uncommon in the viscera; a fasciitis-like pattern of gallbladder injury may not be rare, but to our knowledge it has not been explicitly reported as such in any age group. Osseous metaplasia, or heterotopic bone, in the gallbladder is rare and has not to our knowledge been reported in a pediatric patient. We report a 7-year-old boy with sickle cell disease who presented with right upper quadrant abdominal pain. An ultrasonograph demonstrated a dilated common bile duct with sludge and stones. A cholecystectomy was performed. Grossly the gallbladder showed numerous pigmented choleliths, and histologically there was cholecystitis with a fasciitis-like fibrous proliferation containing scattered osteoclast-like giant cells and an area of osseous metaplasia. This report, describing a pattern that could be termed "cholecystitis ossificans," expands the histologic spectrum of chronic cholecystitis, a common disease with a poorly understood pathogenesis.

Heterotopic ossifications in midline abdominal scars: a critical review of the literature

Heterotopic ossification (HO) is the formation of bone outside the skeletal system, including old incisions. Although a well-known complication after orthopaedic surgery, it is still considered an uncommon phenomenon after vascular surgery. Recent data, however, show that up to 25% of all patients develop HO after midline abdominal surgery. In this article, we present the case of a symptomatic HO, 7 years after an aortobiiliac prosthetic reconstruction for an abdominal aortic aneurysm. Furthermore, we review current insights into the aetiology and show bone morphogenetic proteins to play a crucial role. Treatment options are also reviewed, but lacking any supportive evidence for other therapies, surgical excision with primary closure is the treatment of choice.

Myositis ossificans circumscripta: a paediatric case and review of the literature

Myositis ossificans circumscripta (MOC), characterised by non-neoplastic heterotopic bone formation in soft tissue and skeletal muscle, is rare in children. At onset, it is difficult to distinguish MOC from a musculoskeletal infection or neoplasm, particularly in absence of trauma, and a biopsy is frequently required. We describe an 11-year-old boy with MOC in his thigh. At admission, minor local trauma was referred, and clinical examination revealed a tender and painful mass in the left thigh. Hypothesising a periarticular infection, a wide-spectrum antibiotic and an anti-inflammatory drug were given. The magnetic resonance imaging revealed an enlarged mass with marked enhancement of the lesion and a central, irregular non-enhanced area due to necrosis. After incisional biopsy, the histopathological examination found immature osteoblasts inside striated muscle fibres, as well as proliferating fibroblasts, which are all compatible with MOC, thereby ruling out infection or malignancy. The CT scan showed calcified deposits arranged in a ring, thus confirming MOC; a radiological follow-up was suggested to detect the lesion's maturation. Three months after diagnosis, surgical excision was performed. The post-operative period was uneventful. Six months later, the child was in good condition, with no signs of recurrence. In the literature, 57 paediatric cases have been described; most of these had an acute course, required excision and then had a favourable evolution. Our case study confirms the good prognosis of MOC and underlines how this benign condition should be considered in children presenting a tender and painful soft-tissue swelling.

Cutaneous myositis ossificans: an appropriate descriptor for fibro-osseous lesion of the external auditory canal

Myositis ossificans is a benign pseudosarcomatous bone-forming lesion, histologically characterized by 2 components: a spindle (myo)fibroblastic cell population and a bony component that is arranged in a "zonal" pattern. It mainly affects the deep soft tissues of limbs, but its occurrence in other unusual locations, such as abdomen, inside nerves, and the subcutaneous fat, has been reported. The existence of myositis ossificans restricted to the skin has rarely been published under the term "fibro-osseous lesion of the external auditory canal." Here, we describe an additional case in the external auditory canal, emphasizing its differential diagnosis and alerting dermatopathologists and pathologists to the possibility of encountering such lesion in this anatomic location. For purposes of unifying terms, we propose that cases similar to ours be called "cutaneous myositis ossificans" instead of fibro-osseous lesion of the external auditory canal.

Dedifferentiated chromophobe renal cell carcinoma with massive osteosarcoma-like divergent differentiation: a singular entity in the spectrum of retroperitoneal calcifying tumors

Sarcomatoid change in renal cell carcinoma is the result of the dedifferentiation of the "parent" tumor into a high-grade malignancy characterized by sarcoma-like features and associated with an accelerated clinical course and poorer prognosis. Any of the renal cell carcinoma subtypes can undergo sarcomatoid dedifferentiation, with the chromophobe variant being the most prone. The present report describes the case of a woman affected by a classic chromophobe renal cell carcinoma that developed dedifferentiation accompanied by a very rare osteosarcoma-like divergent differentiation, which constituted about 90% of the entire retroperitoneal mass. In addition to presenting the relevant imaging, histopathological, and immunohistochemical findings, this article briefly discusses the main differential diagnosis of retroperitoneal ossifying/ calcifying masses, which could give rise to diagnostic problems either in small biopsies or at imaging.

Imaging characteristics of heterotopic mesenteric ossification on FDG PET and Tc-99m bone SPECT

A CT scan of a 69-year-old male patient, performed for staging of suspected lung carcinoma, incidentally showed an irregular lesion of 10 cm in the upper abdomen. Further investigation using FDG-PET showed only moderately increased glucose metabolism, whereas Tc-99m MDP SPECT revealed intense osteoblastic activity inside the lesion. A CT-guided biopsy was performed and histologic analysis established the diagnosis of heterotopic mesenteric ossification. This pathology is rare and mostly diagnosed when it is complicated by small bowel obstruction.

Myositis ossificans associated with subclinical idiopathic thrombocytopenic purpura: report of a case

A 56-year-old healthy man noticed a stony-hard mass gradually grown in his neck for more than a 6-year period. Examinations revealed 2 additional calcified masses at the esophageal hiatus and retroperitoneum. The cut-surface of the operative specimens showed fibrous and mucinous appearance with many calcified islands. Microscopically, the lesion showed a gradual transform from the central immature area with fibroblasts and mucinous matrix, to the peripheral mature area with woven bone and osteoclasts (zoning phenomenon), which was compatible with the features of mature myositis ossificans. Myositis ossificans is an isolated, benign, nonneoplastic disease typically found in adolescence, after traumatic episode. Similar lesions have been found in the major musculature of patients with increased bleeding tendency. In the present case, idiopathic thrombocytopenic purpura was found to be associated and was suggested to be involved in initiating myositis ossificans. Still, it is extremely rare to observe lesions in these sites synchronously.

Pseudosarcomas of soft tissue

One of the most common and important pitfalls in soft tissue pathology are the so-called pseudosarcomas. These lesions are nonneoplastic; however, their rapid growth, hypercellularity, cytologic atypia, and mitotic activity makes them prone to be misinterpreted as sarcoma. The most common of these lesions are fibroblastic/myofibroblastic and matrix-forming proliferations, including nodular fasciitis, proliferative fasciitis and myositis, ischemic fasciitis, massive localized edema, myositis ossificans, and bizarre parosteal osteochondromatous proliferation and related entities. Most of these lesions rarely recur following simple excision; therefore, their accurate recognition helps prevent excessive therapy.