Interorgan communication in neurogenic heterotopic ossification: the role of brain-derived extracellular vesicles

Brain-derived extracellular vesicles participate in interorgan communication after traumatic brain injury by transporting pathogens to initiate secondary injury.Inflammasome-related proteins encapsulated in brain-derived extracellular vesicles can cross the blood‒brain barrier to reach distal tissues.These proteins initiate inflammatory dysfunction,such as neurogenic heterotopic ossification.This recurrent condition is highly debilitating to patients because of its relatively unknown pathogenesis and the lack of effective prophylactic intervention strategies.Accordingly,a rat model of neurogenic heterotopic ossification induced by combined traumatic brain injury and achillotenotomy was developed to address these two issues.Histological examination of the injured tendon revealed the coexistence of ectopic calcification and fibroblast pyroptosis.The relationships among brain-derived extracellular vesicles,fibroblast pyroptosis and ectopic calcification were further investigated in vitro and in vivo.Intravenous injection of the pyroptosis inhibitor Ac-YVAD-cmk reversed the development of neurogenic heterotopic ossification in vivo.The present work highlights the role of brain-derived extracellular vesicles in the pathogenesis of neurogenic heterotopic ossification and offers a potential strategy for preventing neurogenic heterotopic ossification after traumatic brain injury.

Piezo1 expression in chondrocytes controls endochondral ossification and osteoarthritis development

Piezo proteins are mechanically activated ion channels,which are required for mechanosensing functions in a variety of cell types.While we and others have previously demonstrated that the expression of Piezo1 in osteoblast lineage cells is essential for boneanabolic processes,there was only suggestive evidence indicating a role of Piezo1 and/or Piezo2 in cartilage.Here we addressed the question if and how chondrocyte expression of the mechanosensitive proteins Piezo1 or Piezo2 controls physiological endochondral ossification and pathological osteoarthritis(OA)development.Mice with chondrocyte-specific inactivation of Piezo1(Piezo1^(Col2a1Cre)),but not of Piezo2,developed a near absence of trabecular bone below the chondrogenic growth plate postnatally.Moreover,all Piezo1^(Col2a1Cre) animals displayed multiple fractures of rib bones at 7 days of age,which were located close to the growth plates.While skeletal growth was only mildly affected in these mice,OA pathologies were markedly less pronounced compared to littermate controls at 60 weeks of age.Likewise,when OA was induced by anterior cruciate ligament transection,only the chondrocyte inactivation of Piezo1,not of Piezo2,resulted in attenuated articular cartilage degeneration.Importantly,osteophyte formation and maturation were also reduced in Piezo1^(Col2a1Cre) mice.We further observed increased Piezo1 protein abundance in cartilaginous zones of human osteophytes.Finally,we identified Ptgs2 and Ccn2 as potentially relevant Piezo1 downstream genes in chondrocytes.Collectively,our data do not only demonstrate that Piezo1 is a critical regulator of physiological and pathological endochondral ossification processes,but also suggest that Piezo1 antagonists may be established as a novel approach to limit osteophyte formation in OA.

Endochondral ossification of hindlimbs in embryonic development of Japanese Quail(Coturnix japonica)

The endochondral ossification of hindlimb is essential to a bird’s ability to stand,walk and fly.Most hindlimb is ossified in the embryos before hatching in precocial birds.However,the molecular mechanisms of hindlimb ossification in birds is still unclear.Therefore,we tried to examine the process of hindlimb ossification and its molecular regulation by using an animal model—Japanese Quail(Coturnix japonica).We selected four critical stages(Embryo Day:E6,E8,E12 and E16) of skeletal development of embryonic quails for hindlimb skeleton staining to show the process of endochondral ossification and to examine the molecular regulation of endochondral osteogenesis by RNA-Seq analysis.The results showed that ossification became increased with embryonic development and most hindlimb was ossified before hatching.RNA-Seq analysis revealed that various signaling pathways were involved with endochondral ossification with thyroid hormone signaling and WNT signaling pathway particularly enriched.Moreover,the expression levels of 42 genes were continuously upregulated and 14 genes were continuously downregulated from E6 to E16.The present study might provide new insights into complex molecular mechanisms in regulation of endochondral ossification.

High formability Mg-Zn-Gd wire facilitates ACL reconstruction via its swift degradation to accelerate intra-tunnel endochondral ossification

After reconstructing the anterior cruciate ligament(ACL),unsatisfactory bone tendon interface healing may often induce tunnel enlargement at the early healing stage.With good biological features and high formability,Magnesium-Zinc-Gadolinium(ZG21)wires are developed to bunch the tendon graft for matching the bone tunnel during transplantation.Microstructure,tensile strength,degradation,and cytotoxicity of ZG21 wire are evaluated.The rabbit model is used for assessing the biological effects of ZG21 wire by Micro-CT,histology,and mechanical test.The SEM/EDS,immunochemistry,and in vitro assessments are performed to investigate the underlying mechanism.Material tests demonstrate the high formability of ZG21 wire as surgical suture.Micro-CT shows ZG21 wire degradation accelerates tunnel bone formation,and histologically with earlier and more fibrocartilage regeneration at the healing interface.The mechanical test shows higher ultimate load in the ZG21 group.The SEM/EDS presents ZG21 wire degradation triggered calcium phosphate(Ca-P)deposition.IHC results demonstrate upregulation of Wnt3a,BMP2,and VEGF at the early phase and TGFβ3 and Type II collagen at the late phase of healing.In vitro tests also confirmed the Ca-P in the metal extract could elevate the expression of Wnt3a,βcatenin,ocn and opn to stimulate osteogenesis.Ex vivo tests of clinical samples indicated suturing with ZG21 wire did not weaken the ultimate loading of human tendon tissue.In conclusion,the ZG21 wire is feasible for tendon graft bunching.Its degradation products accelerated intra-tunnel endochondral ossification at the early healing stage and therefore enhanced bone-tendon interface healing in ACL reconstruction.

DAPK2 promotes autophagy to accelerate the progression of ossification of the posterior longitudinal ligament through the mTORC1 complex

Background:Ossification of the posterior longitudinal ligament(OPLL)is a prevalent condition in orthopedics.While death-associated protein kinase 2(DAPK2)is known to play roles in cellular apoptosis and autophagy,its specific contributions to the advancement of OPLL are not well understood.Methods:Ligament fibroblasts were harvested from patients diagnosed with OPLL.Techniques such as real-time reverse transcriptasepolymerase chain reaction(RT-qPCR)and Western blot analysis were employed to assess DAPK2 levels in both ligament tissues and cultured fibroblasts.The extent of osteogenic differentiation in these cells was evaluated using an alizarin red S(ARS)staining.Additionally,the expression of ossification markers and autophagy markers was quantified.The autophagic activity was further analyzed through LC3 immunofluorescence and transmission electron microscopy(TEM).An in vivo heterotopic bone formation assay was conducted in mice to assess the role of DAPK2 in ossification.Results:Elevated DAPK2 expression was confirmed in both OPLL patient tissues and derived fibroblasts,in contrast to non-OPLL controls.Silencing of DAPK2 significantly curtailed osteogenic differentiation and autophagy in these fibroblasts,evidenced by decreased levels of LC3,and Beclin1,and reduced autophagosome formation.Additionally,DAPK2 was found to inhibit the mechanistic target of the rapamycin complex 1(mTORC1)complex’s activity.In vivo studies demonstrated that DAPK2 facilitates ossification,and this effect could be counteracted by the mTORC1 inhibitor rapamycin.Conclusion:DAPK2 enhances autophagy and osteogenic processes in OPLL through modulation of the mTORC1 pathway.

Heterotopic mesenteric ossification caused by trauma:A case report

BACKGROUND Heterotopic mesenteric ossification(HMO)is a clinically rare condition characterized by the formation of bone tissue in the mesentery.The worldwide reporting of such cases is limited to just over 70 instances in the medical literature.The etiology of HMO remains unclear,but the disease is possibly induced by mechanical trauma,ischemia,or intra-left lower quadrant abdominal infection,leading to the differentiation of mesenchymal stem cells into osteoblasts.Here,we present a rare case of HMO that occurred in a 34-year-old male,who presented with left lower quadrant abdominal pain.CASE SUMMARY We report the case of a 34-year-old male patient who presented with left lower abdominal pain following trauma to the left lower abdomen.He subsequently underwent surgical treatment,and the postoperative pathological diagnosis was HMO.CONCLUSION We believe that although there is limited literature and research on HMO,when patients with a history of trauma or surgery to the left lower abdomen present with corresponding imaging findings,clinicians should be vigilant in distinguishing this condition and promptly selecting appropriate diagnostic and therapeutic interventions.

Ca_v3.3-mediated endochondral ossification in a three-dimensional bioprinted Gel MA hydrogel

The growth plate(GP)is a crucial tissue involved in skeleton development via endochondral ossification(EO).The bone organoid is a potential research model capable of simulating the physiological function,spatial structure,and intercellular communication of native GPs.However,mimicking the EO process remains a key challenge for bone organoid research.To simulate this orderly mineralization process,we designed an in vitro sh Ca_(v)3.3 ATDC5-loaded gelatin methacryloyl(Gel MA)hydrogel model and evaluated its bioprintability for future organoid construction.In this paper,we report the first demonstration that the T-type voltage-dependent calcium channel(T-VDCC)subtype Ca_(v)3.3 is dominantly expressed in chondrocytes and is negatively correlated with the hypertrophic differentiation of chondrocytes during the EO process.Furthermore,Ca_(v)3.3 knockdown chondrocytes loaded with the Gel MA hydrogel successfully captured the EO process and provide a bioink capable of constructing layered and orderly mineralized GP organoids in the future.The results of this study could therefore provide a potential target for regulating the EO process and a novel strategy for simulating it in bone organoids.

Catheter-Assisted Interlaminar Approach for Cervical Epidural Steroid Injection in Patient with Cervical Stenosis Caused by Ossification of Posterior Longitudinal Ligament: A Case Report

We present the case of a 64-year-old man with cervical ossification of the posterior longitudinal ligament (OPLL) experiencing chronic neck pain and radiculopathy for 6 months. A catheter-assisted interlaminar Cervical Epidural Steroid Injection (CESI) was performed under fluoroscopic guidance, targeting the affected C2-C6 levels. Significant improvement was observed after this procedure, with decreased pain scores (visual analogue scale (VAS) 8 to 2) and improved mobility. This technique not only enhances the effectiveness of CESI but also reduces the likelihood of complications such as stroke or epidural hematoma and thus provides an alternative treatment option for patients with multiple stenotic levels who are unsuitable for surgery or are unresponsive to conservative therapy such as medication or physical therapy.

The role of vascular endothelial growth factor in ossification

Osteogenesis and angiogenesis are two closely correlated processes during bone growth, development, remodelling and repair. Vascular endothelial growth factor （VEGF） is an essential mediator during the process of angiogenesis. Based on an extensive literature search, which was carried out using the PubMed database and the keywords of osteogenesis, VEGF, endochondral ossification and intramembranous ossification, this manuscript reviews the role of VEGF in ossification, with emphasis on its effect in endochondral and intramembranous ossification. Osteogenesis and angiogenesis are closely correlated processes. VEGF acts as an essential mediator durin~ these processes. It not only functions in bone an^io^enesis but also in various aspects of bone develooment.

Chondrogenesis mediates progression of ankylosing spondylitis through heterotopic ossification

Ankylosing spondylitis(AS)is chronic inflammatory arthritis with a progressive fusion of axial joints.Anti-inflammatory treatments such as anti-TNF-αantibody therapy suppress inflammation but do not effectively halt the progression of spine fusion in AS patients.Here we report that the autoimmune inflammation of AS generates a microenvironment that promotes chondrogenesis in spine ligaments as the process of spine fusion.Chondrocyte differentiation was observed in the ligaments of patients with earlystage AS,and cartilage formation was followed by calcification.Moreover,a large number of giant osteoclasts were found in the inflammatory environment of ligaments and on bony surfaces of calcified cartilage.Resorption activity by these giant osteoclasts generated marrow with high levels of active TGF-β,which induced new bone formation in the ligaments.Notably,no Osterix+osteoprogenitors were found in osteoclast resorption areas,indicating uncoupled bone resorption and formation.Even at the late and maturation stages,the uncoupled osteoclast resorption in bony interspinous ligament activates TGF-βto induce the progression of ossification in AS patients.Osteoclast resorption of calcified cartilage-initiated ossification in the progression of AS is a similar pathologic process of acquired heterotopic ossification(HO).Our finding of cartilage formation in the ligaments of AS patients revealed that the pathogenesis of spinal fusion is a process of HO and explained why anti-inflammatory treatments do not slow ankylosing once there is new bone formation in spinal soft tissues.Thus,inhibition of HO formation,such as osteoclast activity,cartilage formation,or TGF-βactivity could be a potential therapy for AS.

Neuromuscular electrical stimulation and testosterone did not influence heterotopic ossification size after spinal cord injury: A case series

Neuromuscular electrical stimulation(NMES) and testosterone replacement therapy(TRT) are effective rehabilitation strategies to attenuate muscle atrophy and evoke hypertrophy in persons with spinal cord injury(SCI). However both interventions might increase heterotopic ossification(HO) size in SCI patients. We present the results of two men with chronic traumatic motor complete SCI who also had pre-existing HO and participated in a study investigating the effects of TRT or TRT plus NMES resistance training(RT) on body composition. The 49-year-old male, Subject A, has unilateral HO in his right thigh. The 31-year-old male, Subject B, has bilateral HO in both thighs. Both participants wore transdermal testosterone patches(4-6 mg/d) daily for 16 wk. Subject A also underwent progressive NMES-RT twice weekly for 16 wk. Magnetic resonance imaging scans were acquired prior to and post intervention. Cross-sectional areas(CSA) of thewhole thigh and knee extensor skeletal muscles, femoral bone, and HO were measured. In Subject A(NMES-RT + TRT), the whole thigh skeletal muscle CSA increased by 10%, the knee extensor CSA increased by 17%, and the HO + femoral bone CSA did not change. In Subject B(TRT), the whole thigh skeletal muscle CSA increased by 13% in the right thigh and 6% in the left thigh. The knee extensor CSA increased by 7% in the right thigh and did not change in the left thigh. The femoral bone and HO CSAs in both thighs did not change. Both the TRT and NMES-RT + TRT protocols evoked muscle hypertrophy without stimulating the growth of preexisting HO.

Dystrophic calcification and heterotopic ossification in fibrocartilaginous tissues of the spine in diffuse idiopathic skeletal hyperostosis(DISH)

Diffuse idiopathic skeletal hyperostosis(DISH) is a prevalent noninflammatory spondyloarthropathy characterized by ectopic mineral formation along the anterolateral aspect of the vertebral column, yet little is known about its underlying pathogenesis. Our objective was to evaluate the histopathological features and composition of ectopic mineral within spinal tissues affected by DISH in humans. Thoracic spine segments from six embalmed cadaveric donors(one female and five males;median age 82 years)meeting the radiographic diagnostic criteria for DISH were evaluated using radiological, histological, and physical analyses. Overall,the histological features of ectopic mineralization at individual motion segments were heterogeneous, including regions of heterotopic ossification and dystrophic calcification. Heterotopic ossifications were characterized by woven and lamellar bone,multifocal areas of metaplastic cartilage, and bony bridges along the anterior aspect of the intervertebral disc space. Dystrophic calcifications were characterized by an amorphous appearance, a high content of calcium and phosphorus, an X-ray diffraction pattern matching that of hydroxyapatite, and radiodensities exceeding that of cortical bone. Dystrophic calcifications were found within the anterior longitudinal ligament and annulus fibrosus in motion segments both meeting and not meeting the radiographic criteria for DISH. In summary, our findings indicate that in DISH, ectopic mineral forms along the anterior aspect of the spine by both heterotopic ossification and dystrophic calcification of fibrocartilaginous tissues. Although both types of ectopic mineralization are captured by current radiographic criteria for DISH, dystrophic calcification may reflect a distinct disease process or an early stage in the pathogenesis of DISH.

A Case of Acute Cauda Equina Syndrome for Combined Lumbar Ossification of the Posterior Longitudinal and Yellow Ligament

Acute cauda equina syndrome is known as a symptom of lumbar disc herniation, but to date, there have been no reports of cases caused by lumbar vertebral ligament ossification. We encountered a 61-year-old female patient with acute cauda equina syndrome associated with lumbar vertebral OPLL and OLF. The symptoms were improved by emergency laminectomy. One year after the surgery, the disturbances of gait and urination have been resolved.

Mesenchymal VEGFA induces aberrant differentiation in heterotopic ossification

Heterotopic ossification(HO)is a debilitating condition characterized by the pathologic formation of ectopic bone.HO occurs commonly following orthopedic surgeries,burns,and neurologic injuries.While surgical excision may provide palliation,the procedure is often burdened with significant intra-operative blood loss due to a more robust contribution of blood supply to the pathologic bone than to native bone.Based on these clinical observations,we set out to examine the role of vascular signaling in HO.Vascular endothelial growth factor A(VEGFA)has previously been shown to be a crucial pro-angiogenic and pro-osteogenic cue during normal bone development and homeostasis.Our findings,using a validated mouse model of HO,demonstrate that HO lesions are highly vascular,and that VEGFA is critical to ectopic bone formation,despite lacking a contribution of endothelial cells within the developing anlagen.

Heterotopic ossification after the use of recombinant human bone morphogenetic protein-7

AIM To present the incidence of heterotopic ossification after the use of recombinant human bone morphogenetic protein-7(rhB MP-7) for the treatment of nonunions.METHODS Bone morphogenetic proteins(BMPs) promote bone formation by auto-induction. Recombinant human BMP-7 in combination with bone grafts was used in 84 patients for the treatment of long bone nonunions. All patients were evaluated radiographicaly for the development of heterotopic ossification during the standard assessment for the nonunion healing. In all patients(80.9%) with radiographic signs of heterotopic ossification, a CT scan was performed. Nonunion site palpation and ROM evaluation of the adjacent jointswere also carried out. Factors related to the patient(age, gender), the nonunion(location, size, chronicity, number of previous procedures, infection, surrounding tissues condition) and the surgical procedure(graft and fixation type, amount of rhB MP-7) were correlated with the development of heterotopic ossification and statistical analysis with Pearsons χ~2 test was performed.RESULTS Eighty point nine percent of the nonunions treated with rh BMP-7, healed with no need for further procedures. Heterotopic bone formation occurred in 15 of 84 patients(17.8%) and it was apparent in the routine radiologi-cal evaluation of the nonunion site, in a mean time of 5.5 mo after the rh BMP-7 application(range 3-12). The heterotopic ossification was located at the femur in 8 cases, at the tibia in 6, and at the humerus in οne patient. In 4 patients a palpable mass was present and only in one patient, with a para-articular knee nonunion treated with rhB MP-7, the size of heterotopic ossification affected the knee range of motion. All the patients with heterotopic ossification were male. Statistical analysis proved that patient's gender was the only important factor for the development of heterotopic ossification(P = 0.007). CONCLUSION Heterotopic ossification after the use of rh BMP-7 in nonunions was common but it did not compromise the final clinical outcome in most cases, and affected only male patients.

Conditional disruption of the osterix gene in chondrocytes during early postnatal growth impairs secondary ossification in the mouse tibial epiphysis

In our previous studies, we have found that the prepubertal increase in thyroid hormone levels induces osterix(Osx) signaling in hypertrophic chondrocytes to transdifferentiate them into osteoblasts. To test if Osx expressed in chondrocytes directly contributes to transdifferentiation and secondary ossification, we generated Osx^flox/flox;Col2-Cre-ERT2 mice and knocked out Osx with a single injection of tamoxifen at postnatal day(P) 3 prior to evaluation of the epiphyseal bone phenotype by μCT, histology, and immunohistochemistry(IHC) at P21. Vehicle(oil)-treated Osx^flox/flox;Col2-Cre-ERT2 and tamoxifen-treated, Cre-negative Osx^flox/flox mice were used as controls.μCT analysis of tibial epiphyses revealed that trabecular bone mass was reduced by 23% in the Osx conditional knockout(c KO) compared with control mice. Trabecular number and thickness were reduced by 28% and 8%,respectively, while trabecular separation was increased by 24% in the c KO mice. Trichrome staining of longitudinal sections of tibial epiphyses showed that bone area and bone area adjusted for total area were decreased by 22% and 18%, respectively. IHC studies revealed the presence of abundant Osx-expressing prehypertrophic chondrocytes in the epiphyses of control mice at P10, but not in the cKO mice. Furthermore, expression levels of MMP13, COL10, ALP, and BSP were considerably reduced in the epiphyses of cKO mice. We also found that Osx overexpression in ATDC5 chondrocytes increased expression of Col10, Mmp13, Alp, and Bsp. Our data indicate that Osx expressed in chondrocytes plays a significant role in secondary ossification by regulating expression of genes involved in chondrocyte hypertrophy and osteoblast transdifferentiation.

Pulsed Lavage in Cementless Total Hip Arthroplasty Reduces the Incidence ofBrooker Grade 3 and 4 Heterotopic Ossifications

Heterotopic ossification (HO) may cause pain, and can lead to loss of hip motion after total hip arthroplasty (THA). There is evidence that pulsed lavage may lower the incidence of HO formation. We assessed the effect of pulsed lavage on the incidence of HO in 87 male patients after THA. All patients received an uncemented THA through a posterolateral approach. 39 patients were treated with pulsed lavage (index group) and 48 males were treated without pulsed lavage (historical control group, matched on aetiology, gender, surgical approach and type of prosthesis). Both groups followed the same postoperative treatment regimen. HO severity was scored in both groups according to the Brooker classification by three blinded orthopaedic surgeons one year postoperatively. Good inter-observer agreement (Kappa 0.7) for scoring HO was found. The incidence of HO (51%) in the index group did not differ significantly (p = 0.53) from the control group (58%). However, the incidence of clinically relevant HO (Brooker grades 3 and 4) was significantly lower (p = 0.04) in the index group (3%) as compared to the control group (17%). These results suggest a beneficial effect of pulsed lavage on the incidence of severe heterotopic ossification after cementless THA in male patients.

Lumbar Disc Herniation with End-Plate Fracture and Secondary Ossification Mimicking an Epidural Tumor: A Case Report

We report a unique case of lumbar disc herniation, in particular, with end-plate and surrounded by extensive ossification, mimicking a tumor with calcification. A 69-year-old female suffered from right buttock and leg pain. Computed tomography (CT) showed an intracanalar mass with calcification or ossification, which most likely originated from the vertebral body at the L1/2 level epidural space. On a T1-weighted gadolinium magnetic resonance image, the capsule of the mass was enhanced and not only the content of the mass but also that of the L2 vertebral body were partially and slightly enhanced. The final pathological diagnosis was disc herniation with end-plate fracture and secondary ossification. A combination of these pathological conditions as accompanied by both end-plate fractures and extensive secondary ossifications has not been previously reported. This rare pathological condition needs to be recognized as a differential diagnosis.

Single cell analysis reveals inhibition of angiogenesis attenuates the progression of heterotopic ossification in Mkx^(−/−)mice

Tendon heterotopic ossification(HO)is characterized by bone formation inside tendon tissue,which severely debilitates people in their daily life.Current therapies fail to promote functional tissue repair largely due to our limited understanding of HO pathogenesis.Here,we investigate the pathological mechanism and propose a potential treatment method for HO.Immunofluorescence assays showed that the Mohawk(MKX)expression level was decreased in human tendon HO tissue,coinciding with spontaneous HO and the upregulated expression of osteochondrogenic and angiogenic genes in the tendons of Mkx^(−/−)mice.Single-cell RNA sequencing analyses of wild-type and Mkx^(−/−)tendons identified three cell types and revealed the excessive activation of osteochondrogenic genes during the tenogenesis of Mkx^(−/−)tendon cells.Single-cell analysis revealed that the gene expression program of angiogenesis,which is strongly associated with bone formation,was activated in all cell types during HO.Moreover,inhibition of angiogenesis by the small-molecule inhibitor BIBF1120 attenuated bone formation and angiogenesis in the Achilles tendons of both Mkx mutant mice and a rat traumatic model of HO.These findings provide new insights into the cellular mechanisms of tendon HO and highlight the inhibition of angiogenesis with BIBF1120 as a potential treatment strategy for HO.

Port-site metastasis of unsuspected gallbladder carcinoma with ossification after laparoscopic cholecystectomy:A case report

BACKGROUND Unsuspected gallbladder carcinoma(UGC)refers to cholecystectomy due to benign gallbladder disease,which is pathologically confirmed as gallbladder cancer during or after surgery.Port-site metastasis(PSM)of UGC following laparoscopic cholecystectomy is rare,especially after several years.CASE SUMMARY A 55-year-old man presenting with acute cholecystitis and gallstones was treated by laparoscopic cholecystectomy in July 2008.Histological analysis revealed unexpected papillary adenocarcinoma of the gallbladder with gallstones,which indicated that the tumor had spread to the muscular space(pT1b).Radical resection of gallbladder carcinoma was performed 10 d later.In January 2018,the patient was admitted to our hospital for a mass in the upper abdominal wall after surgery for gallbladder cancer 10 years ago.Laparoscopic exploration and complete resection of the abdominal wall tumor were successfully performed.Pathological diagnosis showed metastatic or invasive,moderately differentiated adenocarcinoma in fibrous tissue with massive ossification.Immunohistochemistry and medical history were consistent with invasion or metastasis of gallbladder carcinoma.His general condition was well at follow-up of 31 mo.No recurrence was found by ultrasound and epigastric enhanced computed tomography.CONCLUSION PSM of gallbladder cancer is often accompanied by peritoneal metastasis,which indicates poor prognosis.Once PSM occurs after surgery,laparoscopic exploration is recommended to rule out abdominal metastasis to avoid unnecessary surgery.