[Pathological Diagnosis and Genetic Alterations of Meningioma].

Meningiomas, renowned for their histological diversity, are one of the most prevalent brain tumors. Some meningiomas show unusual histomorphology, especially in intraoperative rapid diagnosis. Therefore, clinical and radiological information is crucial for pathological diagnosis. Before the 2021 World Health Organization Classification of Tumors of the Central Nervous System(5th edition), pathological diagnosis relied solely on histopathological features. However, this classification introduced new diagnostic criteria for anaplastic meningiomas, which now include TERT promoter mutations and the homozygous deletion of CDKN2A/B, indicating the necessity of genetic analysis. Some rhabdoid and papillary meningiomas have BAP1 alterations, which tend to demonstrate an aggressive clinical course and may represent a phenotype of BAP1-related tumor predisposition syndrome. Heterozygous deletion of CDKN2A/B and loss of H3 p.K28me3(K27me3)are also associated with poor prognosis. Although some immunohistochemical markers like MTAP may serve as surrogates for the homozygous deletion of CKKN2A/B, genetic analysis is required to confirm TERT promoter mutations. Therefore, in routine clinical practice, neurosurgeons and pathologists prioritize appropriate formalin fixation to facilitate genetic analysis using pathological specimens.

Evaluating Cellularity Estimation Methods: Comparing AI Counting with Pathologists' Visual Estimates.

The development of next-generation sequencing (NGS) has enabled the discovery of cancer-specific driver gene alternations, making precision medicine possible. However, accurate genetic testing requires a sufficient amount of tumor cells in the specimen. The evaluation of tumor content ratio (TCR) from hematoxylin and eosin (H&E)-stained images has been found to vary between pathologists, making it an important challenge to obtain an accurate TCR. In this study, three pathologists exhaustively labeled all cells in 41 regions from 41 lung cancer cases as either tumor, non-tumor or indistinguishable, thus establishing a "gold standard" TCR. We then compared the accuracy of the TCR estimated by 13 pathologists based on visual assessment and the TCR calculated by an AI model that we have developed. It is a compact and fast model that follows a fully convolutional neural network architecture and produces cell detection maps which can be efficiently post-processed to obtain tumor and non-tumor cell counts from which TCR is calculated. Its raw cell detection accuracy is 92% while its classification accuracy is 84%. The results show that the error between the gold standard TCR and the AI calculation was significantly smaller than that between the gold standard TCR and the pathologist's visual assessment (p<0.05). Additionally, the robustness of AI models across institutions is a key issue and we demonstrate that the variation in AI was smaller than that in the average of pathologists when evaluated by institution. These findings suggest that the accuracy of tumor cellularity assessments in clinical workflows is significantly improved by the introduction of robust AI models, leading to more efficient genetic testing and ultimately to better patient outcomes.

The white ring sign is useful for differentiating between fundic gland polyps and gastric adenocarcinoma of the fundic gland type.

Background and study aims Gastric adenocarcinoma of the fundic gland type (GA-FG) is characterized by an elevated lesion with vessel dilation exhibiting branching architecture (DVBA). However, this feature is also found in fundic gland polyps (FGPs), posing a challenge in their differentiation. In this study, we aimed to investigate the clinicopathological features of gastric elevated lesions with DVBA and assess the efficacy of the white ring sign (WRS) as a novel marker for distinguishing between FGPs and GA-FGs. Methods We analyzed 159 gastric elevated lesions without DVBA and 51 gastric elevated lesions with DVBA, further dividing the latter into 39 in the WRS-positive group and 12 in the WRS-negative group. The clinicopathological features, diagnostic accuracy, and inter-rater reliability were analyzed. Results Univariate and multivariate analyses for gastric elevated lesions with DVBA identified the histological type consistent with FGPs and GA-FGs, along with the presence of round pits in the background gastric mucosa, as independent predictors. FGPs were present in 92.3% (36/39) of the WRS-positive group and GA-FGs were observed in 50.0% (6/12) of the WRS-negative group. WRS positivity and negativity exhibited high diagnostic accuracy, with 100% sensitivity, 80.0% specificity, and 94.1% accuracy for FGPs, and 100% sensitivity, 86.7% specificity, and 88.2% accuracy for GA-FGs. Kappa values for WRS between experts and nonexperts were 0.891 and 0.841, respectively, indicating excellent agreement. Conclusions WRS positivity and negativity demonstrate high diagnostic accuracy and inter-rater reliability for FGPs and GA-FGs, respectively, suggesting that WRS is a useful novel marker for distinguishing between FGPs and GA-FGs.

Granulocyte colony-stimulating factor-producing lung cancer complicated with antiphospholipid antibody syndrome: a case report.

No reports on granulocyte colony-stimulating factor-producing lung cancer associated with antiphospholipid antibody syndrome. A 73-year-old man was referred to our department to undergo surgery for lung cancer in the right upper lobe. His examination results suggested that his condition was caused by an elevated white blood cell count and an increased inflammatory response due to granulocyte colony-stimulating factor production. The presence of antiphospholipid antibody syndrome was suspected, and the decrease in coagulation factors was considered to be inhibited by the lupus anticoagulant. Perioperatively, the patient was treated with heparin and steroids, and a thoracoscopically assisted right upper lobectomy was performed. Postoperatively, histopathological examination revealed pleomorphic carcinoma, and the patient tested negative for anticardiolipin IgG antibodies. In lung cancer patients with elevated white blood cell counts, fever, and an inflammatory response, granulocyte colony-stimulating factor-producing lung cancer is an important differential diagnosis. Additionally, when coagulation abnormalities are observed preoperatively, a thorough examination is necessary to prepare for perioperative management.

Comparison of diagnostic accuracy between linked color imaging and autofluorescence imaging in patients with ulcerative colitis: A prospective observational study.

BACKGROUND AND AIM: Image enhancement endoscopy techniques, such as linked color imaging (LCI) and autofluorescence imaging (AFI), have shown promise in diagnosing mucosal inflammation in ulcerative colitis (UC). However, no studies have directly compared the diagnostic efficacy of LCI and AFI. This prospective observational study aimed to compare their diagnostic accuracy for histological healing in UC. METHODS: This study included 81 UC patients, resulting in a total of 204 endoscopic images captured using LCI and AFI, respectively. Spearman's rank correlation coefficients assessed the correlation between LCI and AFI coloration and Geboes histopathology score (GHS). Six endoscopists, who were blinded to clinicopathological features, evaluated these images, and subsequently, the diagnostic accuracy was evaluated. RESULTS: Spearman's rank correlation coefficients between LCI index, AFI index (reverse gamma value), and GHS were 0.324 and -0.428, respectively (P < 0.001), indicating a significant correlation between LCI and AFI coloration and histological healing. In LCI and AFI classifications, mean values for diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 76.3 ± 2.2 versus 77.8 ± 2.7, 91.8 ± 4.0 versus 83.2 ± 7.6, 53.4 ± 10.0 versus 70.0 ± 5.3, 74.0 ± 3.5 versus 80.0 ± 1.6, and 82.9 ± 5.2 versus 75.5 ± 7.5, respectively. No significant difference in diagnostic accuracy existed between LCI and AFI classifications. However, LCI displayed higher sensitivity than AFI while AFI showed higher specificity compared with LCI (P < 0.05). CONCLUSIONS: LCI and AFI offer comparable diagnostic accuracy for histological healing. Clinically, it is necessary to recognize diagnostic features characterized by higher sensitivity in LCI and greater specificity in AFI.

A case of non-bacterial thrombotic endocarditis on the aortic valve following coronary angiography.

Nonbacterial thrombotic endocarditis (NBTE) on the aortic valve involves fibrin and platelet aggregate formation, potentially leading to embolic events. We present a case of NBTE on the aortic valve following coronary angiography (CAG) in a 54-year-old man with multiple comorbidities. Surgical thrombectomy was performed owing to acute cerebral infarcts. This case highlights the significance of considering that mechanical trauma from catheterization during CAG can trigger thrombus formation.

Cardiac sarcoidosis in a patient with ulcerative colitis: A case report and literature review.

RATIONALE: Both ulcerative colitis (UC) and sarcoidosis are chronic inflammatory diseases with unknown etiologies and are rare. However, the odds ratio in UC patients has been reported to range from 1.7 to 2.1, suggesting a potential etiology between sarcoidosis and UC. Furthermore, the underlying etiologies of UC and sarcoidosis remain unidentified. Sharing the experience of a UC patient with cardiac sarcoidosis could provide valuable insights to prevent sudden death in UC patients. PATIENT CONCERNS: A 71-year-old Japanese woman was diagnosed with UC at 58-year-old and maintained remission on mesalazine treatment. She complained of just palpitation; therefore, she consulted a cardiologist. DIAGNOSES: The patient received a diagnosis of cardiac sarcoidosis with complicating ulcerative colitis based on the results of N-terminal prohormone of the brain natriuretic peptide (NT-proBNP), imaging examinations, and histology. INTERVENTION: The patient was treated with prednisolone and methotrexate. The prednisolone was then tapered, and the methotrexate dose was adjusted based on her symptoms, imaging results, and laboratory findings. OUTCOME: She no longer had any symptoms, and the abnormal FDG uptake had disappeared after 2 years. LESSON: In UC patients, periodic or additional (in case of symptomatic) electrocardiography and NT-proBNP are recommended for the early detection of cardiac sarcoidosis, a life-threatening complication.

Synchronous multiple lung cancers with hilar lymph node metastasis of small cell carcinoma: A case report.

BACKGROUND: Synchronous multiple lung cancers are rare and refer to the simultaneous presence of two or more primary lung tumors, which present significant challenges in terms of diagnosis and treatment. CASE SUMMARY: We report a case of multiple synchronous lung cancers with hilar lymph node metastasis of small cell carcinoma of unknown origin in a 73-year-old man. Transbronchial lung biopsy revealed squamous cell carcinoma. Although enlargement of lymph node 12u was detected, no distant metastases were observed. The patient was preoperatively diagnosed with T1cN0M0 and underwent thoracoscopic right upper lobectomy with nodal dissection (ND2a). Based on histopathological findings, the primary lesion was squamous cell carcinoma. A microinvasive adenocarcinoma was also observed on the cranial side of the primary lesion. Tumors were detected in two resected lymph nodes (#12u and #11s). Both tumors were pathologically diagnosed as small cell carcinomas. The primary lesion of the small cell carcinoma could not be identified even by whole-body imaging; however, chemotherapy was initiated for hilar lymph node metastasis of the small cell carcinoma of unknown origin. CONCLUSION: Multiple synchronous lung cancers can be accompanied by hilar lymph node metastasis of small cell carcinomas of unknown origin.

Solitary fibrous tumor resembling pulmonary fractionation disease: A case report.

RATIONALE: Preoperative differentiation between pulmonary fractionation and solitary fibrous tumors (SFTs) is challenging. Diaphragmatic primary tumors are relatively rare among SFTs, with limited reports of abnormal vascularity. PATIENT CONCERNS: A 28-year-old male patient was referred to our department for surgical resection of a tumor near the right diaphragm, Thoracoabdominal contrast-enhanced computed tomography (CT) scan revealed a 10 × 8 cm mass lesion at the base of the right lung. The inflow artery to the mass was an anomalous vessel in which the left gastric artery bifurcated from the abdominal aorta, and its origin was the common trunk and right inferior transverse artery. DIAGNOSIS: The tumor was diagnosed as right pulmonary fractionation disease based on the clinical findings. The postoperative pathological examination determined a diagnosis of SFT. INTERVENTIONS: The pulmonary vein was used to irrigate the mass. The patient was diagnosed with pulmonary fractionation and underwent surgical resection. Intraoperative findings revealed a stalked, web-like venous hyperplasia anterior to the diaphragm, contiguous with the lesion. An inflow artery was found at the same site. The patient was subsequently treated using a double ligation technique. The mass was partially contiguous with S10 in the right lower lung and stalked. An outflow vein was identified at the same site, and the mass was removed using an automatic suture machine. OUTCOMES: The patient received follow-up examinations that involved a chest CT scan every 6 months, and no tumor recurrence was reported during 1 year of postoperative follow-up. LESSONS: Differentiating between SFT and pulmonary fractionation disease may be challenging during preoperative diagnosis; therefore, aggressive surgical resection should be considered as SFTs may be malignant. Identification of abnormal vessels using contrast-enhanced CT scans may be effective in reducing surgical time and improving the safety of the surgical procedure.

Concurrent Granulomatous Mastitis and Ductal Carcinoma In Situ.

Granulomatous mastitis (GM) is a benign inflammatory breast disease that often poses diagnostic challenges due to its similar clinical and radiographic features to breast cancer. We report the case of a 34-year-old female with concurrent GM and ductal carcinoma in situ (DCIS). Initially, breast cancer was suspected based on imaging; however, a needle biopsy confirmed GM. Corticosteroid treatment led to a reduction in tumor size, but subsequent imaging continued to suggest the presence of breast cancer. Surgical excision ultimately revealed the coexistence of GM and DCIS. It is essential to consider the possibility of concurrent breast cancer in cases of GM with discordant imaging and pathology findings.

A case of lymphoma mimicking infected internal iliac artery aneurysm.

BACKGROUND: Malignant lymphoma rarely mimics an infected arterial aneurysm and a ruptured arterial aneurysm because of similar imaging findings, leading to misdiagnosis. The hematomas of ruptured aneurysms are radiologically difficult to distinguish from those of malignant lymphoma in emergency settings. Hence, a definitive diagnosis is crucial to avoid unnecessary surgery. CASE PRESENTATION: A man in his 80s with hematuria and shock vital had right internal iliac artery aneurysm (IIAA) and perianeurysmal fluid retention, which appeared to be a ruptured or an infected aneurysm. Treatment was initiated for infected IIAA instead of for ruptured IIAA. Systemic inflammatory response syndrome developed, and the infectious sources were assessed. Pacemaker lead and urinary tract infections were identified and treated; however, blood pressure was unstable. The aneurysm was treated with endovascular aortic aneurysm repair following antibiotic therapy; however, fluid retention increased, and inflammatory status and hematuria deteriorated. Open surgical conversion was performed to manage the infected lesions. Although an iliopsoas abscess was detected during surgery and nephrectomy and ureterectomy were performed to control the hematuria, analysis of the removed tissues led to the pathological diagnosis of diffuse large B-cell lymphoma (DLBCL). CONCLUSIONS: We encountered a case of DLBCL with imaging findings mimicking an infected internal iliac artery aneurysm, and definitive diagnosis was made more than 2 months after the initial examination. Definitively diagnosing malignant lymphoma around an iliac artery aneurysm based merely on symptoms and imaging findings is extremely difficult. Thus, histological examination should be actively performed in atypical infected aneurysms.

The Effectiveness of the Combination of Arterial Infusion Chemotherapy and Radiotherapy for Biliary Tract Cancer: A Prospective Pilot Study.

The standard treatment of unresectable biliary tract cancer (BTC) has shown an insufficient response rate (RR). Our retrospective setting revealed that a combination therapy consisting of intra-arterial chemotherapy plus radiation therapy (IAC + RT) provided a high RR and long-term survival benefits in unresectable BTC. This prospective study aimed to test the effectiveness and safety of IAC + RT as the first-line therapy. The regimen included one-shot IAC with cisplatin, 3-6 months of reservoir IAC (5-FU and cisplatin, q/week), and 50.4 Gy of external radiation. The primary endpoints include the RR, disease control rate, and adverse event rate. This study included seven patients with unresectable BTC without distant metastasis, with five cases classified as stage 4. RT was completed in all cases, and the median number of reservoir IAC sessions was 16. The RR was 57.1% for imaging and 71.4% for clinical assessment, and the disease control rate was 100%, indicating a high antitumor efficacy, which allowed two cases to be transferred to surgery. Five cases of leukopenia and neutropenia; four cases of thrombocytopenia; and two cases of hemoglobin depletion, pancreatic enzyme elevation, and cholangitis were observed, but with no treatment-related deaths. This study revealed a very high antitumor effect with IAC + RT for some unresectable BTC, and it could be useful for conversion therapy.

[Successful rituximab treatment of TAFRO syndrome refractory to glucocorticoids and tocilizumab].

A 53-year-old man was presented with fever, eyelid edema, and thrombocytopenia. Based on examination outcomes, he was diagnosed with immune thrombocytopenia. He was prescribed prednisolone (PSL) at 0.5 mg/kg/day; subsequently, his platelet count improved and fever improved. PSL dose was tapered and stopped without relapse. However, 1 month later, the patient presented to our hospital with fever, generalized edema, thrombocytopenia, and acute renal failure. Computed tomography revealed multiple lymphadenopathies, hepatomegaly, pleural effusion, and ascites. Bone marrow biopsy indicated reticulin fibrosis, and lymph node biopsy revealed mixed-type Castleman disease. Based on these findings, he was diagnosed with grade 5 TAFRO syndrome (very severe). Steroid pulse therapy and tocilizumab were ineffective in improving his condition. Therefore, rituximab was administered instead of tocilizumab, and his condition eventually improved. The optimal treatment for TAFRO syndrome is yet to be established. If tocilizumab is ineffective as the second-line treatment, then rituximab might be effective.

Low-grade papillary Schneiderian carcinoma with TP53 mutation: a case report and review of the literature.

BACKGROUND: Low-grade papillary Schneiderian carcinoma (LGPSC) is a relatively new entity of the sinonasal tract and is characterized by a bland morphology simulating sinonasal papilloma, invasive growth pattern with pushing borders, and aggressive clinical behavior with multiple recurrences and metastatic potential. Recently, DEK::AFF2 fusions were identified in LGPSC. However, some LPGSCs lack DEK::AFF2 fusion, and the molecular features of these tumors have not been clarified. CASE PRESENTATION: A 69-year-old man presented with a discharge of pus from his left cheek. Computed tomography revealed a mass involving the left maxillary sinus, ethmoid sinus, and nasal cavity with the destruction of the orbital wall. The biopsy specimens showed that the tumor had a predominantly exophytic, papillary growth and did not have an apparent stromal invasion. The tumor was composed of multilayered epithelium that showed bland morphology with a round to polygonal shape, abundant eosinophilic cytoplasm, and uniform nuclei. Dense neutrophilic infiltrates were focally present. Immunohistochemically, CK5/6 was strongly and diffusely positive, and p16 was negative. p63 was mainly positive in the basal layer, and EMA was predominantly expressed in the outermost cell layer. DNA-based targeted sequencing showed TP53 R175H mutation, whereas neither EGFR nor KRAS mutation was identified. Reverse transcription polymerase chain reaction and fluorescence in situ hybridization revealed no DEK::AFF2 fusion. CONCLUSIONS: We describe the first case of TP53-mutant LGPSC and review the literature. LGPSC is a genetically heterogeneous entity, and the recognition of this rare entity and comprehensive assessment of clinicopathological and molecular findings are crucial for the correct pathological diagnosis and clinical management.

[Thymic Neuroendocrine Tumor Associated with Multiple Endocrine Neoplasia Type 1].

Multiple endocrine neoplasia (MEN) type 1 is a hereditary syndrome characterized by hyperplasia and adenoma of the parathyroid gland, pancreatic tumor, and pituitary tumor. We report a rare case of thymic neuroendocrine tumor diagnosed after removal of a thymic tumor following pancreatic and parathyroid surgery. A 35-year-old man was diagnosed with MEN type 1 by hypercalcemia and gastrinemia with a ureteral tone. Two well defined nodules in the anterior mediastinum on computed tomography (CT), and a high degree of accumulation on positron emission tomography (PET) was noted. Surgery was performed through a median sternotomy with anterior mediastinal tumor resection. Pathology showed thymic neuroendocrine tumor (NET). Immunostaining results were different from pancreatic NET and duodenal NET, and a diagnosis of primary thymic NET was made. Postoperative radiation therapy was completed as adjuvant therapy, and the patient is alive without reccurrence.

Local recurrence after successful endoscopic submucosal dissection for rectal mucinous mucosal adenocarcinoma: A case report.

BACKGROUND: Mucinous adenocarcinoma of the colorectum is a rare histological subtype characterized by an abundant mucinous component. Mucinous tumors are frequently diagnosed at an advanced stage, which indicates an aggressive subtype. However, few case reports have been published, and little information is available concerning genetic alterations in mucinous adenocarcinoma. CASE SUMMARY: A 76-year-old man underwent en bloc endoscopic submucosal dissection (ESD) for the management of a type 0-Is+IIa lesion. Histological examination revealed an intramucosal mucinous adenocarcinoma with signet-ring cell carcinoma and well-to-moderately differentiated tubular adenocarcinoma. Three years after the ESD, local recurrence was detected by an endoscopic examination, revealing a new 0-Is+IIa lesion with a phenotype similar to the previously resected lesion. Re-ESD was chosen for the management of the recurrent tumor, and the histological examination showed positive tumor infiltration at the vertical margin. Additional surgical resection was performed for the curative treatment. Genetic analysis showed pathogenic alterations in RNF43 and TP53 in the adenoma and an additional SMAD4 alteration in the carcinoma. CONCLUSION: This mucinous mucosal adenocarcinoma case was suggested to have an aggressive phenotype and a careful and close follow-up are required.

Early recurrence of Rosai-Doefman disease after total removal resection: a case report.

BACKGROUND: Rosai-Dorfman disease (RDD) involving the central nervous system (CNS) is rare and observed in 5% of all patients with extranodal RDD. According to a previous report, gross total resection is curative; however, we encountered a case of recurrence following gross total resection. We discuss our case and review previous reports on recurrent RDD. CASE DESCRIPTION: A 68-year-old woman came to the hospital complaining of left parietal mass. A tumor that had partially eroded the frontal bone was found. As the lesion was suspected to be malignant, we performed a total resection. Pathology results were indicative of an RDD. We did not prescribe adjuvant therapy because total resection was performed. However, after a year, abnormal accumulation in the left parietal bone was observed on FDG-PET. This was considered as recurrence, and re-excision was performed. Pathological assessments confirmed the recurrence of RDD. CONCLUSIONS: Our case demonstrated the recurrence of RDD following total resection. Future reports should assess these peculiarities. This will facilitate discussions on the risk factors and the effectiveness of treatment methods.

Subcellular localization of hTERT in breast cancer: insights into its tumorigenesis and drug resistance mechanisms in HER2-immunopositive breast cancer.

Human telomerase reverse transcriptase (hTERT) is highly expressed in various cancers, including breast cancer. Although telomere elongation is an essential role for hTERT, the nuclear export after oxdative stress has also been shown in several cancer cell lines and is associated with drug-resistance in vitro. As only a few reports focused on the subcellular localization of hTERT in clinical specimens, we performed immunohistochemistry (IHC) and analyzed the correlation between intracellular hTERT expression and the clinicopathological characteristics to identify the clinical significance of hTERT subcellular expression in breast cancers. 144 invasive breast cancers classified by IHC subtype without primary systemic therapy (PST), were selected from a surgical resection cohort and were immunostained for hTERT, p-STAT3, p-AKT and p-ERK. The nuclear and/or cytoplasmic staining intensity and proportion of hTERT were scored and compared with clinicopathological parameters. The nuclear hTERT expression was significantly correlated with HER2 expression (p = 0.00156), and the scores were significantly correlated with p-STAT3 and p-AKT expression scores (r = 0.532, p = 0.000587 and r = 0.345, p = 0.0339, respectively) in the HER2-immunopositive breast cancer including luminal-HER2 and HER2 subtypes. Furthermore, hTERT was expressed more in cytoplasm in the specimens after PST than those before PST, and the score tended to be negatively correlated with tumor shrinkage rate in HER2 subtype (r = -0.593, p = 0.0705). These results suggest that nuclear and/or cytoplasmic hTERT may play a different role before and after PST including the tumorigenesis and drug-resistance in breast cancer. Suppression of cytoplasmic hTERT expression may lead to more effective strategy for drug-resistant HER2 subtype in breast cancer.

Interventional Bridging Therapy for Radical Cardiac Surgery in a Patient Seemed to be Inoperable Due to Very Poor Left Ventricular Function: A Case Report.

Cases that are inoperable owing to poor preoperative conditions are sometimes encountered. However, there are some cases that are led to radical treatment by performing bridge therapy. Here, we presented a case of a patient with complex cardiac disease in an inoperable state who underwent bridging therapy that led to successful surgical treatment. A 73-year-old male who received hemodialysis treatment and had severe aortic valve stenosis and coronary artery disease planned surgical treatment. However, he was deemed inoperable owing to his low cardiac function and hemodynamic instability. Therefore, to escape from a fatal condition, we first performed balloon aortic valvuloplasty and percutaneous coronary intervention as palliative procedures. Subsequently, his cardiac function and hemodynamic stability remarkably improved; therefore, after 1 month, we performed a successful radical surgical treatment. Even in inoperable patients, bridging therapy leading to radical treatment is possible.

Primary Chondrosarcoma of the Right Fourth Rib Resected at the Marginal Margin: A Case Report.

Primary chondrosarcoma of the ribs is relatively rare, and its basic treatment is surgical resection. In cases with positive resection margins, additional resection is considered, but its indications are unclear. However, reported cases with positive resection margins have been limited. We report a 71-year-old man whose medical checkup revealed an abnormal shadow in the chest. The findings from chest computed tomography, axial T2-weighted magnetic resonance imaging (MRI), and contrast-enhanced MRI led to a diagnosis of chondrosarcoma of the right fourth rib, and surgical resection was performed. The chest wall defect was reconstructed with a Marlex mesh. Postoperative histopathologic diagnosis was grade 2 chondrosarcoma. Gross resection margins, which were marginal, were negative, and the resection margin was grade 1. The patient was followed up without adjuvant therapy and did not undergo additional surgery. For chondrosarcomas with negative gross margins but a marginal margin, additional resection should be considered depending on the histologic grade of the margins. In cases with extensive resection of the chest wall, it is useful to reconstruct the chest wall while paying careful attention to infection control.