Double Negativity of MRI-Detected and Pathologically-Diagnosed Extramural Venous Invasion is a Favorable Prognostic Factor for Rectal Cancer.

BACKGROUND: Extramural venous invasion (EMVI) is a prognostic factor in rectal cancer. There are two types: EMVI detected by magnetic resonance imaging (MRI) (mr-EMVI) and EMVI detected by pathology (p-EMVI). They have been separately evaluated, but they have not yet been concurrently evaluated. We therefore evaluate both mr-EMVI and p-EMVI in rectal cancer at the same time and clarify their association with prognosis. PATIENTS AND METHODS: Included were the 186 consecutive patients who underwent complete radical resection of tumors ≤ stage III at Wakayama Medical University Hospital, Japan, between 2010 and 2018. All underwent preoperative MRI examination, and were reassessed for EMVI by a radiologist. Surgically resected specimens were then reassessed for EMVI by a pathologist. We assessed the correlation between positivity of mr-EMVI and p-EMVI and prognosis, and the clinicopathological background behind them. RESULTS: Patients with double negativity for mr-EMVI and p-EMVI had better prognosis than patients with mr-EMVI or p-EMVI positivity (p < 0.0001). Positivity for mr-EMVI or p-EMVI was a poor independent prognostic factor in multivariate analysis. CONCLUSIONS: Combined analysis of mr-EMVI and p-EMVI may enable prediction of postoperative prognosis of rectal cancer. Patients with double negativity of mr-EMVI and p-EMVI had better prognosis than patients with some form of positivity. Stated differently, patients with positivity of mr-EMVI, p-EMVI, or both had a poorer prognosis than those with double negativity. Postoperative adjuvant chemotherapy may improve poor prognosis. Combined evaluation of mr-EMVI and p-EMVI may be used to predict clinical outcomes and may be an effective prognostic predictor of rectal cancer.

Implication of KMT2C and TSC2 variants in the tumorigenesis of acquired cystic disease-associated renal cell carcinomas.

In 2020, acquired cystic disease-associated renal cell carcinomas (ACD-RCCs) were reported to harbor KMT2C and TSC2 variants: however, their carcinogenic implication has not yet been reported. This study aimed to explore the variant features of KMT2C and TSC2 in ACD-RCC and their implication in ACD-RCC tumorigenesis. Eleven ACD-RCCs, 10 ACD-RCC-like cysts, and 18 background kidneys were retrieved. The background kidneys consisted of atrophic thyroid follicle-like tubules. They included four with clustered cysts, two with eosinophilic changes, and one each with clear cell changes and sieve-like changes in the renal tubules. First, DNA-targeted sequencing of KMT2C and TSC2 whole exons was performed on eight ACD-RCC samples. Subsequently, a custom DNA panel was designed to include the recurrent KMT2C and TSC2 variants based on the sequencing results. Second, DNA-targeted sequencing was performed on the remaining samples using a custom panel targeting the recurrent variants. Additionally, immunohistochemistry was performed for KMTC, H3K4me1, H3K4me3, TSC2, and GPNMB on the ACD-RCCs. Six of the 11 ACD-RCC cases harbored KMT2C and TSC2 variants, including nine likely pathogenic variants. In contrast to ACD-RCC, 1 of the 9 ACD-RCC-like cysts harbored both variants. Immunohistochemical analysis did not support the loss of function in ACD-RCCs harboring KMT2C and TSC2 variants. KMT2C and TSC2 variant frequencies were higher in ACD-RCC than in other renal cell carcinomas. However, KMT2C and TSC2 are unlikely to be the primary drivers of ACD-RCC development.

Targeted Next-Generation Sequencing of Flat Urothelial Lesions Reveals Putative Pathobiological Pathways, Potential Biomarkers, and Rational Therapeutic Targets.

Flat urothelial lesions are controversial diagnostic and prognostic urologic entities whose importance relies mainly on their ability to progress to muscle-invasive tumors via urothelial carcinoma in situ (CIS). However, the carcinogenetic progression of preneoplastic flat urothelial lesions is not well established. Moreover, predictive biomarkers and therapeutic targets of the highly recurrent and aggressive urothelial CIS lesion are lacking. Using a targeted next-generation sequencing (NGS) panel of 17 genes directly involved in bladder cancer pathogenesis, we investigated alterations of genes and pathways with clinical and carcinogenic implications on 119 samples of flat urothelium, including normal urothelium (n = 7), reactive atypia (n = 10), atypia of unknown significance ( n = 34), dysplasia ( n = 23), and CIS (n = 45). The majority of the flat lesions were tumor-associated but grossly/microscopically or temporally separated from the main tumor. Mutations were compared across flat lesions and concerning the concomitant urothelial tumor. Associations between genomic mutations and recurrence after intravesical bacillus Calmette-Guerin treatment were estimated with Cox regression analysis. TERT promoter mutations were highly prevalent in intraurothelial lesions but not in the normal or reactive urothelium, suggesting that it is a critical driver mutation in urothelial tumorigenesis. We found that synchronous atypia of unknown significance-dysplasia-CIS lesions without concomitant papillary urothelial carcinomas had a similar genomic profile that differed from atypia of unknown significance-dysplasia lesions associated with papillary urothelial carcinomas, which harbored significantly more FGFR3, ARID1A, and PIK3CA mutations. KRAS G12C and ERBB2 S310F/Y mutations were exclusively detected in CIS and were associated with recurrence after bacillus Calmette-Guerin treatment (P = .0006 and P = .01, respectively). This targeted NGS study revealed critical mutations involved in the carcinogenetic progression of flat lesions with putative pathobiological pathways. Importantly, KRAS G12C and ERBB2 S310F/Y mutations were identified as potential prognostic and therapeutic biomarkers for urothelial carcinoma.

Intestinal Mucosa-Associated Lymphoid Tissue Lymphoma Transforming into Diffuse Large B-Cell Lymphoma in a Young Adult Patient with Neurofibromatosis Type 1: A Case Report.

Background: Neurofibromatosis type 1 (NF1) is a hereditary cancer syndrome characterized by multiple café-au-lait macules on the skin. Lymphoproliferative malignancies associated with NF1 are limited, although the most common are brain tumors. Case presentation: A 22-year-old woman with NF1 was admitted due to abdominal pain and bloody diarrhea. Her laboratory data exhibited macrocytic anemia and elevated IgA levels. Image studies showed diffuse increased wall thickening in the transverse and descending colon without lymphadenopathy and hepatosplenomegaly. A colonoscopy revealed a hemorrhagic ulcerated mass. Pathological analysis of the tumor tissues confirmed IgA-expressing mucosa-associated lymphoid tissue (MALT) lymphoma with histological transformation. Moreover, whole-exome sequencing in tumor tissues and peripheral blood mononuclear cells identified a somatic frameshift mutation of the A20 gene, which represents the loss of function. The patient responded well to R-CHOP chemotherapy, but the disease relapsed after 1 year, resulting in a lethal outcome. Conclusions: MALT lymphoma in children and young adults is extremely rare and is possibly caused by acquired genetic changes. This case suggests a novel association between hereditary cancer syndrome and early-onset MALT lymphoma.

Paneth-like cells in renal cell carcinomas and in cysts associated with acquired cystic kidney disease: Clinicopathologic analysis, comparative study and description of precursor lesions.

Paneth-like cells (PLCs) are different from Paneth cells (PCs) and contain Paneth-like granules, which have been reported in non-neoplastic conditions and in neoplasms of various organs. PLCs have been reported in clear cell renal cell carcinoma (CCRCC), but not in non-CCRCC, including acquired cystic disease-associated renal cell carcinoma (ACD-RCC). We analyzed clinicopathological features of 24 acquired cystic disease-associated renal cell carcinoma (ACD-RCC) with PLCs (ACD-RCCP+) and compared with those of 23 ACD-RCCs without PLCs (ACD-RCCP-). Approximately half of ACD-RCCs had PLCs and that almost all kidneys harboring ACD-RCC had cysts with PLCs. The fact that many ACD-RCCs and the cysts had PLCs is further evidence that the cyst with vacuoles and complex architecture might be a precursor lesion for ACD-RCC. The presence of PLCs may provide additional morphologic clue for distinguishing ACD-RCC from PRCC in challenging differential diagnostic workup in acquired cystic disease of the kidney setting.

[Erdheim-Chester disease diagnosed with right atrium tumors].

Erdheim-Chester disease (ECD) is a very rare form of the non-Langerhans histiocytic multisystem disorder. The cardiac involvement is often challenging and is associated with poor prognosis. Transthoracic echocardiography was used to detect right atrium tumors in a 62-year-old man with heart failure who was admitted to our hospital. The circumferential soft tissue sheathing of the aorta (coated aorta) and fat infiltration around the kidneys (hairy kidneys) was seen on a contrast-enhanced computed tomography strongly suspecting ECD imaging. The patient was diagnosed with ECD based on histopathology reports of the surgical resection tumor. The characteristic imaging findings of ECD may contribute to an early and accurate diagnosis.

Perivascular epithelioid cell tumor of the descending colon mimicking a gastrointestinal stromal tumor: a case report.

BACKGROUND: We present a case of perivascular epithelioid cell tumor (PEComa), which clinically and histologically mimics a gastrointestinal stromal tumor (GIST). CASE PRESENTATION: A 42-year-old woman was found to have a mass in the left flank during her annual medical checkup. Computed tomography examination revealed a submucosal tumor of the descending colon. Surgeons and radiologists suspected that the lesion was a GIST, and left hemicolectomy was performed without biopsy. Microscopic examination showed that the lesion was composed of spindle and epithelioid cells, which were immunohistochemically negative for c-kit and positive for platelet-derived growth factor receptor (PDGFR) α. Initial diagnosis of PDGFRα-positive GIST was made. However, gene analysis did not reveal mutations in PDGFRα. Additional immunohistochemistry showed that tumor cells were positive for human melanin black 45 (HMB45), melanA, and the myogenic marker calponin. A final diagnosis of PEComa was made. CONCLUSION: PEComa should be included in the differential diagnosis of PDGFRα-positive spindle cell tumors in the wall of the gastrointestinal tract.

Rosai-Dorfman disease differentiated from a posterior mediastinal tumour: a case report.

Rosai-Dorfman disease presenting solely with intrathoracic lesions is exceptionally rare. Herein, we report the case of a 53-year-old man presenting with a posterior mediastinal tumour. Computed tomography revealed a 7-cm soft tissue shadow in the posterior mediastinum. Positron emission tomography-computed tomography demonstrated a high maximum standardized uptake value of 10.35 in the tumour, with no evidence of lymph node or other organ involvement. Serum marker levels were within the normal range. Thoracoscopic surgery was performed to obtain a biopsy for a definitive diagnosis and treatment planning. Postoperative histological findings revealed a diffuse infiltration of eosinophilic histiocytes, lymphocytes, and plasma cells. Immunohistochemical analysis indicated positivity for S-100 protein, oct-2, and cyclin D1 in these histiocytes. Consequently, the patient was diagnosed with Rosai-Dorfman disease and is currently asymptomatic, undergoing regular monitoring without treatment as an outpatient. The absence of characteristic findings, such as bilateral cervical lymphadenopathy, posed challenges in preoperative diagnosis.

Comparative analysis of non-coding and coding DNA mutations in flat urothelial lesions: biological implications and insights.

Recent research in urothelial carcinoma (UC) has focused on coding mutations, leaving the significance of non-coding mutations unexplored. This study aims to evaluate non-coding DNA mutation frequencies compared to coding regions in normal urothelium and flat lesions, exploring their implications for tumor biology. Using targeted next-generation sequencing with UC-related gene panel, we analyzed non-coding and coding DNA mutation frequencies across 119 samples of flat urothelium encompassing various lesion types. Mutation patterns were examined based on the presence of associated flat or papillary tumors, and we investigated the correlation between mutation rates in target genes and genetic mutations within genomic regions. Intronic mutations (IMs) displayed variability across lesions, with normal urothelium (NU) exhibiting the highest frequency (43%) and urothelial carcinoma in situ (CIS) the lowest (9%). We observed similar sets of frequently mutated genes in both intronic and exonic regions, distinct from promoter region mutations. Although IMs paralleled exonic mutations in NU, reactive atypia, and atypia of unknown significance (AUS), they were less prevalent in dysplasia (DYS) and CIS. In contrast to CIS-associated AUS and DYS lesions, AUS-DYS lesions associated with papillary tumors exclusively exhibited recurrent intronic mutations involving FGFR3 and ERCC2, aligning with mutation patterns seen in exonic regions. ERCC2 intronic mutations correlated with the mutation rates of the gene panel. Our findings suggest that intronic mutations significantly contribute to tumor heterogeneity in urothelial lesions and may potentially be linked to genomic instability, warranting further investigation.

Small sized centroblasts as poor prognostic factor in follicular lymphoma - Based on artificial intelligence analysis.

Histological assessment of centroblasts is an important evaluation in the diagnosis of follicular lymphoma, but there is substantial observer variation in assessment among hematopathologists. We aimed to perform quantitative morphological analysis of centroblasts in follicular lymphoma using new artificial intelligence technology in relation to the clinical prognosis. Hematoxylin and eosin slides of lesions were prepared from 36 cases of follicular lymphoma before initial chemotherapy. Cases were classified into three groups by clinical course after initial treatment. The 'excellent prognosis' group were without recurrence or progression of follicular lymphoma within 60 months, the 'poor prognosis' group were those that had relapse, exacerbation, or who died due to the follicular lymphoma within 60 months, and the 'indeterminate prognosis' group were those without recurrence or progression but before the passage of 60 months. We created whole slide images and image patches of hematoxylin and eosin sections for all cases. We designed an object detection model specialized for centroblasts by fine-tuning YOLOv5 and segmented all centroblasts in whole slide images. The morphological characteristics of centroblasts in relation to the clinical prognosis of follicular lymphoma were analyzed. Centroblasts in follicular lymphoma of the poor prognosis group were significantly smaller in nuclear size than those in follicular lymphoma of the excellent prognosis group in the following points: median of nuclear area (p = 0.013), long length (p = 0.042), short length (p = 0.007), nuclear area of top 10 % cells (p = 0.024) and short length of top 10 % cells (p = 0.020). Cases with a mean nuclear area of <55 µm2 had poorer event-free survival than those with a mean nuclear area of ≥55 µm2 (p < 0.0123). AI methodology is suggested to be able to surpass pathologist's observation in capturing morphological features. Small-sized centroblasts will likely become a new prognostic factor of follicular lymphoma.

Laparoscopic-Assisted Total Resection and Endorectal Pull-Through Technique for Congenital Megarectum with Anorectal Malformation.

BACKGROUND/PURPOSE: Congenital megarectum (CMR) is sometimes associated with anorectal malformations (ARM), although there is no established therapeutic strategy. This study aims to clarify the clinical features of ARM with CMR, and to demonstrate the effectiveness of a surgical treatment, namely laparoscopic-assisted total resection and endorectal pull-through technique. METHODS: We conducted a review of the clinical records of the patients with ARM with CMR treated at our institution between January 2003 and December 2020. RESULTS: Seven of 33 cases of ARM (21.2%) were diagnosed with CMR, four males and three females. The types of ARM were 'intermediate' in four, and 'low' in three patients. Five of the seven patients (71.4%) required resection of megarectum for intractable constipation and underwent laparoscopic-assisted total resection and endorectal pull-through technique. Bowel function was improved after resection in all five cases. All five specimens showed hypertrophy of the circular fibers, and three of them showed abnormal location of ganglion cells within the circular muscle fibers. CONCLUSIONS: CMR often causes intractable constipation and requires resection of the dilated rectum. Laparoscopic-assisted total resection and endorectal pull-through technique for ARM with CMR considered to be an effective, minimally invasive treatment for intractable constipation. LEVEL OF EVIDENCE FOR CLINICAL RESEARCH PAPERS: Level Ⅳ. TYPE OF STUDY: Treatment study.

Angioimmunoblastic T-Cell Lymphoma after Treatment of Classic Hodgkin Lymphoma: A Case Report.

We report a case of a 24-year-old man who developed angioimmunoblastic T-cell lymphoma (AITL) after treatment for refractory lymphocyte-rich classic Hodgkin lymphoma (LR-CHL). This patient was treated with the BV+AVD (brentuximab vedotin, doxorubicin, vinblastine, and dacarbazine) protocol for LR-CHL but progressed before completing chemotherapy. The pathological imaging showed the typical findings of LR-CHL at the first onset and first progression. Rescue chemotherapy and high-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (AHSCT) were performed for refractory LR-CHL, and complete remission was achieved. However, the recurrence was suspected 6 months after AHSCT. The pathological findings of the lymph node biopsy at this time were different from those of the previous two lymph node biopsies, demonstrating findings of AITL. The finding of the immunohistochemical staining and polymerase chain reaction results supported the diagnosis. Although it has been reported that the risk for the development of non-Hodgkin lymphoma after treatment for Hodgkin lymphoma is increased, most are B-cell lymphomas, and few cases of AITL have been reported. AITL is a type of peripheral T-cell lymphoma that generally occurs in middle-aged and elderly people and that rarely occurs in young people. Here, we were able to make an accurate diagnosis by performing re-examination even when recurrence of LR-CHL was suspected. As there are no detailed case reports of AITL developing into secondary non-Hodgkin lymphoma, here we report on an identified case.

Rituximab Monotherapy for Grade 2-3 Lymphomatoid Granulomatosis with Central Nervous System Involvement in a Patient Receiving Methotrexate for Rheumatoid Arthritis.

Lymphomatoid granulomatosis (LYG) is a rare lymphoproliferative disorder (LPD). The optimal management strategy of methotrexate (MTX) related-LPD with central nervous system (CNS) involvement and histological features of LYG remains unclear. We herein report a case of grade 2-3 LYG in a rheumatoid arthritis patient, in which an intracranial mass accompanied by hemorrhaging and pulmonary and skin lesions developed. The patient received successful rituximab monotherapy. The tumor cells in the skin and brain showed monoclonal and oligoclonal proliferation, respectively. Our case suggests that rituximab monotherapy may be effective against MTX-LPD with CNS involvement, especially in cases with LYG histology.

Severe systemic inflammation mimicking TAFRO syndrome following COVID-19.

TAFRO syndrome is a rare systemic inflammatory disease. Its pathogenesis mainly involves excessive cytokine secretion and autoimmune dysfunction. Although its etiology is unclear, some viral infections have been reported to cause it. Here, we report a case of severe systemic inflammation mimicking TAFRO syndrome that arose after COVID-19. A 61-years-old woman suffered from a continuous fever, ascites, and edema after contracting COVID-19. She developed progressive thrombocytopenia, renal failure, and elevated C-reactive protein levels. She was tentatively diagnosed with multisystem inflammatory syndrome in adults (MIS-A) and received steroid pulse therapy. However, she exhibited worsening fluid retention and progressive renal failure, which are not typical of MIS-A. A bone marrow examination showed reticulin myelofibrosis and an increased number of megakaryocytes. Although a definitive diagnosis of TAFRO syndrome was not made according to current diagnostic criteria, we determined that her symptoms were clinically consistent with those of TAFRO syndrome. Combination therapy, including steroid pulse therapy, plasma exchange, rituximab, and cyclosporine, improved her symptoms. There are pathological similarities between hyperinflammation that arises after COVID-19 and TAFRO syndrome in terms of the associated cytokine storms. COVID-19 may have triggered the development of systemic inflammation mimicking TAFRO syndrome in this case.

IgG4-associated fibrosing mediastinitis requiring differentiation from posterior mediastinal tumour: A case report.

A 71-year-old man, who was found to have a posterior mediastinal tumour, was referred to our hospital. Contrast-enhanced computed tomography (CT) showed a 15-cm soft tissue shadow in the posterior mediastinum, with many affected areas and a gradually increasing pattern. We also detected oligemic areas with poor contrast-filling. There was no invasion into the adjacent vertebral body and the blood vessels penetrating the interior were intact. Positron emission tomography-CT revealed a high maximum standardized uptake level of 4.53 in the mediastinal masses. We performed thoracoscopic surgery for the biopsy. Histological findings showed lymphoplasmacytic infiltration in the fibrous stroma as well as storiform fibrosis. Immunohistochemical examination revealed abundant infiltration of immunoglobulin G4 (IgG4)-positive plasma cells and 40% IgG4/IgG-positive plasma cells. Postoperative serum examinations showed a high serum IgG4 level (570 mg/dl). Accordingly, we diagnosed the patient with IgG4-related fibrosing mediastinitis, a rare manifestation of IgG4-related disease.

Therapeutic Penetrating Keratoplasty in a Case of Corneal Perforation Caused by Colletotrichum gloeosporioides Infection.

Background: Corneal infection of Colletotrichum gloeosporioides is uncommon and usually limited to the anterior stroma. However, we observed a case of corneal stromal perforation caused by this fungus under a compromised condition. Case: A 73-year-old woman consulted us with a severe corneal ulceration. She was a tangerine orange farmer who suffered from rheumatoid arthritis for more than ten years. Before consultation with us, she received pterygium excision in her right eye. She then developed a corneal ulceration and received topical glucocorticoid therapy upon diagnosis of rheumatoid arthritis-related stromal ulcer in the eye. At the first consultation with us, a corneal ulceration was observed in the inferotemporal area of her right cornea. Biological examination detected a filamentous fungus, Colletotrichum gloeosporioides. Topical and systemic antifungal treatments were not significantly effective. Fourteen days after consultation, the lesion grew worse, leading to stromal perforation, which was treated by therapeutic penetrating keratoplasty using a preserved corneal button. Conclusions: Topical glucocorticoid could accelerate the growth of Colletotrichum gloeosporioides before diagnosis, even though the primary cause of corneal ulceration development might be rheumatoid arthritis.

Adrenocortical carcinoma with inferior vena cava tumor thrombus found during surgery.

Introduction: The safety and efficacy of minimally invasive approaches for adrenocortical carcinoma with inferior vena cava tumor thrombus have not yet been established. We report a case of large adrenocortical carcinoma with inferior vena cava tumor thrombus found perioperatively which required conversion from a laparoscopic to an open procedure. Case presentation: A 71-year-old woman with right-side 10-cm diameter adrenocortical carcinoma was scheduled for laparoscopic adrenalectomy. The operation was converted to open surgery, however, because inferior vena cava tumor thrombus, which was not detected by preoperative imaging modalities, was found during surgery. Conclusion: In patients with large adrenocortical carcinoma, the possible presence of inferior vena cava thrombus should be considered when selecting surgical procedures.

Pathologic Image Classification of Flat Urothelial Lesions Using Pathologic Criteria-Based Deep Learning.

OBJECTIVES: Pathologic diagnosis of flat urothelial lesions is subject to high interobserver variability. We expected that deep learning could improve the accuracy and consistency of such pathologic diagnosis, although the learning process is a black box. We therefore propose a new approach for pathologic image classification incorporating the diagnostic process of the pathologist into a deep learning method. METHODS: A total of 267 H&E-stained slides of normal urothelium and urothelial lesions from 127 cases were examined. Six independent convolutional neural networks were trained to classify pathologic images according to six pathologic criteria. We then used these networks in the main training for the final diagnosis. RESULTS: Compared with conventional manual analysis, our method significantly improved the classification accuracy of images of flat urothelial lesions. The automated classification showed almost perfect agreement (weighted κ = 0.98) with the consensus reading. In addition, our approach provides the advantages of reliable diagnosis corresponding to histologic interpretation. CONCLUSIONS: We used deep learning to establish an automated subtype classifier for flat urothelial lesions that successfully combines traditional morphologic approaches and complex deep learning to achieve a learning mechanism that seems plausible to the pathologist.