Hemostasis with Metallic Stent for Multiple Metastatic Pancreatic Tumors Complicated with Hemobilia.

Introduction: Hemobilia, which refers to bleeding from the bile duct, is rare and difficult to treat. We report a case of successful hemostasis of a pancreatic tumor complicated by hemobilia. Case Presentation: A 76-year-old man was referred to our hospital with a pancreatic head tumor. Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasonography-FNA were performed, and the patient was diagnosed with pancreatic metastasis of renal cell carcinoma. After discharge, the patient noted worsening jaundice and progressive anemia and was readmitted. ERCP reveals active bleeding from the duodenal papillae. The patient was placed on a fully covered metallic stent and discharged after confirming hemostasis. Conclusion: Renal cell carcinoma is a tumor with abundant blood flow. If hemobilia occurs, bleeding from pancreatic metastatic tumors should be considered. Additionally, hemostasis using a fully covered metallic stent is useful for treating hemobilia in tumors.

The association between surgical site infection and postoperative colorectal cancer recurrence and the effect of laparoscopic surgery on prognosis.

PURPOSE: Studies have shown that surgical site infection (SSI) incidence is lower in patients undergoing laparoscopic surgery. Therefore, we reported the SSI countermeasures adopted by our institution and aimed to evaluate the association between SSI occurrence and postoperative colorectal cancer recurrence and the usefulness of laparoscopic surgery for prognosis. METHODS: Among the patients with colorectal cancer who underwent radical surgery at our hospital between January 2015 and December 2017, 197 with stage I-III cancer without distant metastases were included. We retrospectively analyzed patients' electronic medical records and classified them into the non-SSI (without SSI, n = 159) and SSI (with SSI, n = 38) groups. We calculated and compared the 5-year relapse-free survival (RFS) and overall survival (OS) rates. Additionally, we assessed the relationship between prognosis in the non-SSI, incisional SSI, and organ/space SSI groups and the usefulness of laparoscopic surgery. RESULTS: The 5-year RFS and OS were 80.5% versus 63.2% (P = 0.024; hazard ratio [HR], 2.065; 95% confidence interval [CI], 1.099-3.883) and 88.7% versus 84.2% (P = 0.443; HR, 1.436; 95% CI, 0.570-3.617), respectively. The SSI group had a significantly worse 5-year RFS prognosis. Regarding the relationship with laparoscopic surgery, the SSI incidence was 45.0% (9/20 cases) and 16.4% (29/177 cases) with laparotomy and laparoscopic surgery, respectively, indicating a significantly reduced SSI occurrence with laparoscopic surgery (P = 0.005). CONCLUSION: Patients with SSI were at high risk for colorectal cancer recurrence, and laparoscopic surgery may be useful for reducing SSI.

Subserosal Layer and/or Pancreatic Invasion Based on Anatomical Features as a Novel Prognostic Indicator in Patients with Distal Cholangiocarcinoma.

The American Joint Committee on Cancer (AJCC) 8th edition T-staging system for distal cholangiocarcinoma (DCC) proposes classification according to the depth of invasion (DOI); nevertheless, DOI measurement is complex and irreproducible. This study focused on the fibromuscular layer and evaluated whether the presence or absence of penetrating fibromuscular invasion of DCC contributes to recurrence and prognosis. In total, 55 patients pathologically diagnosed with DCC who underwent surgical resection from 2002 to 2022 were clinicopathologically examined. Subserosal layer and/or pancreatic (SS/Panc) invasion, defined as penetration of the fibromuscular layer and invasion of the subserosal layer or pancreas by the cancer, was assessed with other clinicopathological prognostic factors to investigate recurrence and prognostic factors. According to the AJCC 8th edition, there were 11 T1, 28 T2, and 16 T3 cases, with 44 (80%) cases of SS/Panc invasion. The DOI was not significantly different for both recurrence and prognostic factors. In the multivariate analysis, only SS/Panc was identified as an independent factor for prognosis (hazard ratio: 16.1; 95% confidence interval: 2.1-118.8, p = 0.006). In conclusion, while the determination of DOI in DCC does not accurately reflect recurrence and prognosis, the presence of SS/Panc invasion may contribute to the T-staging system.

Sensitivity of endoscopic ultrasound-guided fine-needle aspiration cytology and biopsy for a diagnosis of pancreatic ductal adenocarcinoma: A comparative analysis.

The utility of endoscopic ultrasound fine-needle aspiration cytology (EUS-FNAC) or endoscopic ultrasound fine-needle aspiration biopsy (EUS-FNAB) for diagnosis of small and large pancreatic ductal adenocarcinomas (PDACs) remains in question. We addressed this by analyzing 97 definitively diagnosed cases of PDAC, for which both EUS-FNAC and EUS-FNAB had been performed. We subclassified the 97 solid masses into small (n = 35) or large (n = 62) according to the maximum tumor diameter (<24 mm or ≥24 mm) and compared the diagnostic sensitivity (truly positive rate) of EUS-FNAC and of EUS-FNAB for small and large masses. Diagnostic sensitivity of EUS-FNAC did not differ between large and small masses (79.0% vs. 60.0%; p = 0.0763). However, the diagnostic sensitivity of EUS-FNAB was significantly higher for large masses (85.5% vs. 62.9%; p = 0.0213). Accurate EUS-FNAC-based diagnosis appeared to depend on the degree of cytological atypia of cancer cells, which was not associated with quantity of cancer cells. The accuracy of EUS-FNAB-based diagnosis appeared to depend on cancer cell viability in large masses and cancer volume in small masses. Based on the advantages or disadvantages in each modality, both modalities play an important role in the qualitative diagnosis of PDAC as a complementary procedure.

Antemortem Diagnosis of Pulmonary Tumor Thrombotic Microangiopathy in a Patient with Recurrent Breast Cancer: An Autopsy Case Report.

OBJECTIVE: Herein, we report a case of a patient with recurrent breast cancer who was diagnosed antemortem with pulmonary tumor thrombotic microangiopathy (PTTM) using wedge aspiration cytology of the pulmonary artery after breast cancer surgery. CASE SUMMARY: The patient was a 50-year-old woman who underwent mastectomy and axillary lymph node dissection for stage IIIA (T3N2M0) triple-negative left breast cancer. Postoperative follow-up was performed with radiotherapy and anticancer chemotherapy. Seventeen months after the surgery, the patient was hospitalized for right heart failure and diagnosed with pulmonary arterial hypertension. The patient was diagnosed with PTTM following the detection of malignant cells in the pulmonary artery using wedge aspiration cytology. Anti-pulmonary hypertension therapy was administered; however, the patient did not respond and died 26 days after admission. Autopsy revealed multiple microscopic tumor emboli in the pulmonary artery. In portions of the pulmonary artery without embolization, fibro-cellular intimal hyperplasia and stenosis were observed. Tumor embolism was expressed for CK7+/CK20-, consistent with the primary breast cancer. DISCUSSION: Since the primary pathophysiology of PTTM entails narrowing due to fibro-cellular intimal hyperplasia rather than multiple tumor thrombi, the efficacy of chemotherapy combined with vasodilators is discussed.

Transformed Mycosis Fungoides with a Cytotoxic T-Cell Phenotype.

Mycosis fungoides (MF) is a cutaneous T-cell lymphoma and occasionally undergo large cell transformation (transformed MF, TMF), resulting in a poorer clinical outcome. We describe a case of TMF with an immunophenotypic shift. MF showed the CD4 + CD8- T-cell phenotype, while TMF exhibited the CD4-CD8 + T-cell phenotype. Moreover, TMF expressed cytotoxic markers of TIA1 and Granzyme B. A PCR analysis of T-cell receptor genes revealed peak sizes that were the same in both biopsies, indicating that these two lymphomas were derived from the same clone.

Primary Sclerosing Cholangitis Complicated with Aphthoid Colitis Difficult to Diagnose from IgG4-Related Sclerosing Cholangitis.

A 19-year-old man visited our hospital because of diarrhea and blood and liver dysfunction. Magnetic and endoscopic retrograde cholangiography revealed diffuse narrowing of the common biliary tract and intrahepatic biliary tract. A biopsy specimen from the narrowed area of the common biliary tract revealed IgG4-related sclerosing cholangitis (IgG4-SC). Colonoscopy showed multiple aphthoid colitis. He was treated with corticosteroids, and the levels of hepatobiliary enzymes, IgG, and IgG4 gradually decreased. This is an extremely rare case of colitis in which the patient had a phenotype of sclerosing cholangitis similar to IgG4-SC, which was finally diagnosed as primary sclerosing cholangitis.

Diagnostic Categories and Key Features for Pathological Diagnosis of Endoscopic Ultrasound-Guided Fine Needle Aspiration Biopsy Samples of Pancreatic Lesions: A Consensus Study.

OBJECTIVES: This study aimed to establish a reliable and reproducible categorized diagnostic classification system with identification of key features to achieve accurate pathological diagnosis of endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNAB) samples of pancreatic lesions. METHODS: Twelve pathologists examined virtual whole-slide images of EUS-FNAB samples obtained from 80 patients according to proposed diagnostic categories and key features for diagnosis. Fleiss κ was used to assess the concordance. RESULTS: A hierarchical diagnostic system consisting of the following 6 diagnostic categories was proposed: inadequate, nonneoplasm, indeterminate, ductal carcinoma, nonductal neoplasm, and unclassified neoplasm. Adopting these categories, the average κ value of participants was 0.677 (substantial agreement). Among these categories, ductal carcinoma and nonductal neoplasm showed high κ values of 0.866 and 0.837, respectively, which indicated the almost perfect agreement. Key features identified for diagnosing ductal carcinoma were necrosis in low-power appearance; structural atypia/abnormalities recognized by irregular glandular contours, including cribriform and nonuniform shapes; cellular atypia, including enlarged nuclei, irregular nuclear contours, and foamy gland changes; and haphazard glandular arrangement and stromal desmoplasia. CONCLUSIONS: The proposed hierarchical diagnostic classification system was proved to be useful for achieving reliable and reproducible diagnosis of EUS-FNAB specimens of pancreatic lesions based on evaluated histological features.

Scoring system for intraoperative diagnosis of intracranial schwannoma by squash cytology.

OBJECTIVE: To assess the utility of a newly developed squash cytology (SC)-based scoring system for accurate intraoperative diagnosis of schwannoma. METHODS: We first compared SC-based and frozen section (FS) diagnoses with final pathological diagnoses of schwannoma (16 cases), meningioma (39 cases) and low-grade astrocytoma (16 cases). Then, by logistic regression modeling, we identified features of SC preparations that were independently predictive of schwannoma. To develop a diagnostic scoring system, we assigned one point to each feature, and performed receiver operating characteristic analysis to determine the score cut-off value that was most discriminatory for differentiating schwannoma from the other tumour types. We then compared accuracy, sensitivity, and specificity of diagnosis before and after the application of the scoring system. RESULTS: Overall diagnostic concordance rates for SC and FS were almost the same, at 73.2% (52/71) and 77.5% (55/71 cases), respectively. Of the 16 SC features entered into the analysis, the following nine were found to independently predict schwannoma, and were thus incorporated into the scoring system: smooth cluster margins, few or no isolated tumour cells, fibrillary stroma, spindle-shaped nuclei, parallel arrangement of stroma, parallel arrangement of nuclei, presence of anisonucleosis, absence of nucleoli, and hemosiderin deposition. A cut-off score of four items yielded the best sensitivity, specificity and predictive values for prediction of schwannoma. Use of the scoring system improved accuracy of intraoperative diagnosis from 80.3% to 94.4%, sensitivity from 56.2% to 93.8%, and specificity from 87.3% to 94.5%. CONCLUSION: Our proposed SC-based scoring system will increase accuracy of intraoperative diagnosis of schwannoma vs non-schwannoma tumours.

Concordance of the histological diagnosis of type 1 autoimmune pancreatitis and its distinction from pancreatic ductal adenocarcinoma with endoscopic ultrasound-guided fine needle biopsy specimens: an interobserver agreement study.

The histological diagnosis of type 1 autoimmune pancreatitis (AIP) based on the findings obtained by an endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) is feasible, but the diagnostic consistency of this method has not been confirmed. We determined the interobserver agreement among 20 pathologists regarding the diagnosis of type 1 AIP, including the distinction from pancreatic ductal adenocarcinoma (PDAC) using large tissue samples obtained by EUS-FNB. After guidance for diagnosing AIP with biopsy tissues was provided, a round 2 was performed. The median sensitivity and specificity for diagnosing PDAC vs. non-neoplastic diseases were 95.2% and 100%, respectively. In groups of specialists (n = 7) and the generalists (n = 13), Fleiss' к-values increased from 0.886 to 0.958 and from 0.750 to 0.816 in round 2. The concordance was fair or moderate for obliterative phlebitis and storiform fibrosis but slight for ductal lesion of type 1 AIP. Discordant results were due to ambiguous findings and biopsy tissue limitations. Among the specialists, the ratio of cases with perfect agreement regarding the presence of storiform fibrosis increased in round 2, but agreement regarding obliterative phlebitis or ductal lesions was not improved. Although the histological definite diagnosis of type 1 AIP was achieved by most observers in > 60% of the cases, the confidence levels varied. Because some ambiguities exist, the histological diagnostic levels based on the diagnostic criteria of type 1 AIP should not be taken for granted. Guidance is effective for improving accurate PDAC diagnoses (notably by recognizing acinar-ductal metaplasia) and for evaluating storiform fibrosis.

Scatter patterns in lymph node metastases as a novel prognostic indicator in patients with stage III/N2 colorectal cancer.

To classify patients with stage III/N2 colorectal cancer into high- and low-risk groups for recurrence, the present study compared clinicopathological features by immunohistochemical staining. The single-center analysis included 53/668 patients (7.9%) with stage III/N2 colorectal cancer who underwent radical resection between January 2006 and December 2014. The present study examined cancer cell distribution in metastatic lymph nodes and classified patients into a group with circumferential localization patterns like a cystic mass (CLP) and a group with scatter patterns like fireworks (SPF). Subsequently, 5-year relapse-free survival (5Y-RFS) and 5-year overall survival (5Y-OS) rates were compared and the histological type (differentiation degree) of the primary adenocarcinoma was included. The CLP group included 16 patients (30.2%) and the SPF group included 37 patients (69.8%). The 5Y-RFS rates in these groups were 75.0 vs. 37.8%, respectively (P=0.021), and the 5Y-OS rates were 81.3 vs. 48.6% (P=0.033). Patient clinicopathological characteristics exhibited no significant differences between groups. The adenocarcinoma was well differentiated in 14 patients (Well; 26.4%) and moderately (Mod; n=37) or poorly (Por; n=2) differentiated in 39 patients (Mod+Por; 73.6%). Patients were further classified into four groups: Well/CLP (n=6), Well/SPF (n=8), Mod+Por/CLP (n=10) and Mod+Por/SPF (n=29). For Well/CLP vs. Well/SPF, the 5Y-RFS rates were 66.7 vs. 25.0%, respectively (P=0.293), and for Mod+Por/CLP vs. Mod+Por/SPF (80.0 vs. 41.4%; P=0.052), the respective values for 5Y-OS were 66.7 vs. 50.0% (P=0.552) and 90.0 vs. 48.3% (P=0.059). Based on the aforementioned results, the CLP group was considered a low-risk group for recurrence with a relatively good prognosis; however, the SPF group was considered a high-risk group for recurrence with a poor prognosis, suggesting a need for more potent multi-combination chemotherapy in these patients from the early postoperative period.

A patient with paraganglioma undergoing laparoscopic resection: A case report.

Paraganglioma is a very rare extraadrenal nonepithelial tumor. The number of cases of laparoscopic surgery in Paraganglioma is small and controversial. This study encountered a case of successful transperitoneal laparoscopic surgery for a 56-mm paraganglioma in a 53-year-old female. Moreover, previous reports on laparoscopic surgery for paraganglioma are reviewed.

Recognition and pathological features of periampullary region adenocarcinoma with an indeterminable origin.

Determination of the primary tumor in periampullary region carcinomas can be difficult, and the pathological assessment and clinicopathological characteristics remain elusive. In this study, we investigated the current recognition and practices for periampullary region adenocarcinoma with an indeterminable origin among expert pathologists through a cognitive survey. Simultaneously, we analyzed a prospective collection of cases with an indeterminable primary tumor diagnosed from 2008 to 2018 to elucidate their clinicopathological features. All cases with pathological indeterminable primary tumors were reported and discussed in a clinicopathological conference to elucidate if it was possible to distinguish the primary tumor clinically and pathologically. From the cognitive survey, over 85% of the pathologists had experienced cases with indeterminable primary tumors; however, 70% of the cases was reported as pancreatic cancer without definitive grounds. Interpretation of the main tumor mass varied, and no standardized method was developed to determine the primary tumor. During a prospective study, 42 of the 392 periampullary carcinoma cases (10.7%) were considered as tumors with a pathological indeterminable origin. After the clinicopathological conferences, 21 (5.4%) remained indeterminable and were considered final indeterminable cases. Histological studies showed that the tumors spread along both the bile duct and main pancreatic duct; this was the most representative finding of the final indeterminable cases. This study is the first to elucidate and recognize the current clinicopathological features of periampullary region adenocarcinomas with an indeterminable origin. Adequate assessment of primary tumors in periampullary region carcinomas will help to optimize epidemiological data of pancreatic and bile duct cancer.

A deep learning model to detect pancreatic ductal adenocarcinoma on endoscopic ultrasound-guided fine-needle biopsy.

Histopathological diagnosis of pancreatic ductal adenocarcinoma (PDAC) on endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) specimens has become the mainstay of preoperative pathological diagnosis. However, on EUS-FNB specimens, accurate histopathological evaluation is difficult due to low specimen volume with isolated cancer cells and high contamination of blood, inflammatory and digestive tract cells. In this study, we performed annotations for training sets by expert pancreatic pathologists and trained a deep learning model to assess PDAC on EUS-FNB of the pancreas in histopathological whole-slide images. We obtained a high receiver operator curve area under the curve of 0.984, accuracy of 0.9417, sensitivity of 0.9302 and specificity of 0.9706. Our model was able to accurately detect difficult cases of isolated and low volume cancer cells. If adopted as a supportive system in routine diagnosis of pancreatic EUS-FNB specimens, our model has the potential to aid pathologists diagnose difficult cases.

Accuracy of imprint cytology and frozen section histology for intraoperative diagnosis of ovarian epithelial tumors: A comparative study and proposed algorithm.

BACKGROUND: Appropriate surgical treatment of epithelial ovarian tumors is reliant on intraoperative diagnosis. A retrospective study to compare the diagnostic accuracies of imprint cytology (IC) with frozen section histology (FSH) in these tumors was performed. METHODS: About 78 cases of IC-based and FSH-based diagnoses against the final histopathologic diagnoses in terms of both histologic subtype (serous, mucinous, endometrioid, or clear cell tumor) and behavioral type (benign, borderline, or malignant) were compared. The cytomorphologic features of the tumor cells (nuclear atypia, papillary clusters, adenoma cells, and necrosis) in relation to behavioral types were also evaluated. RESULTS: While the diagnostic accuracy of IC and FSH were similar with respect to behavioral type (87% and 88%, respectively), the diagnostic accuracy of IC was superior to that of FSH with respect to histologic subtype (83% and 74%, respectively). Among histopathologically confirmed malignant tumors, the diagnostic accuracy of IC (62/64; 97%) was superior to that of FSH (58/64; 91%). The presence of necrosis and absence of adenoma cells were significantly more prevalent among malignant group than among borderline and benign groups (P < .01, for both). CONCLUSION: Since the presence of necrosis and absence of adenoma cells around the carcinoma cells appear useful in distinguishing malignant and borderline tumors, it was proposed to include IC for further intraoperative assessment of any tumors initially diagnosed as a borderline tumor by FSH.

Intracholecystic tubular non-mucinous neoplasm (ICTN) of the gallbladder: a clinicopathologically distinct, invasion-resistant entity.

Preinvasive tumor-forming gallbladder neoplasms that are composed of small, non-mucinous tubules with complex architecture remain a poorly characterized group. Here, we evaluated the clinicopathological characteristics of this entity. Twenty-eight examples were analyzed. Tumors were invariably pedunculated polyps with thin stalks, often presented as loosely attached intraluminal nodules, with cauliflower architecture (akin to cholesterol polyps) comprised of compact, back-to-back acinar-like, small tubular units with minimal/no cytoplasm showing variable complexity, creating a picture distinct from the other tubular type dysplasia in the gallbladder. Their limited stroma showed distinctive amorphous amyloid-like hyalinization (39%). While some had round nuclei with single prominent nucleoli, others exhibited slightly more elongated nuclei with washed out chromatin reminiscent of papillary thyroid carcinoma. Squamoid/meningothelial-like morules (71%) and subtle neuroendocrine cell clusters (39%) were frequent. The level of cytoarchitectural atypia qualified as high-grade dysplasia (HGD) in all cases, but none were invasive. The background mucosa showed no dysplasia, but cholesterolosis. The majority (n = 8/12) showed diffuse MUC6 expression and lacked MUC5AC expression. Based on these observations, 635 gallbladder carcinomas were re-analyzed for residual/adjacent lesions with entity-defining characteristics disclosed here, and none could be identified. Preinvasive tubular non-mucinous neoplasm of the gallbladder, which we propose to classify as intracholecystic tubular non-mucinous neoplasm, is a clinicopathologically discrete entity, which tends to occur in uninjured gallbladders and in association with cholesterol polyps. By being tubular, non-mucinous and MUC6-positive, it is akin to intraductal tubulopapillary neoplasms of pancreatobiliary tract, but it is also different in many other aspects. Although their cytoarchitectural complexity warrants an HGD/carcinoma classification, they do not show invasion and their distinct characteristics warrant their separate classification.

Clonally Related Plasmablastic Lymphoma Simultaneously Occurring with Diffuse Large B-Cell Lymphoma.

Plasmablastic lymphoma (PBL) is a rare aggressive lymphoma. Although it was first described in HIV- (human immunodeficiency virus-) infected patients, PBL has been diagnosed in patients with other immunodeficiencies as well as in immunocompetent patients. PBL immunohistochemically expresses plasmacytic markers and lacks pan B-cell markers. The cells of origin of PBL are considered to be plasmablasts. MYC gene rearrangement and MYC overexpression are frequently found in PBL, but the pathogenesis of PBL is yet to be elucidated. Here, we report a case of composite lymphoma of PBL and diffuse large B-cell lymphoma (DLBCL); that is, PBL in the urinary bladder and DLBCL in the nasal cavity occurred simultaneously. We extracted DNA from the two lymphomas for polymerase chain reaction and sequenced the amplified immunoglobulin heavy variable genes and the complementarity-determining region- (CDR-) 3. The sequence of the CDR3 region of both tumors matched. MYC rearrangement was found in the bladder tumor but not in the nasal tumor. The patient was treated with R-CHOP (rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisone), and durable remission had been obtained. The results of the DNA analysis indicated that both PBL and DLBCL emerged from common postgerminal B cells. This case may help to elucidate the pathogenesis of PBL.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: A Case Report.

BACKGROUND: Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a non-tumorous benign lesion that originates in the spleen and It is rare. CASE PRESENTATION: A 59-year-old man visited his physician for a checkup. Ultrasonography showed a mass in the spleen, and the patient was referred to our hospital. He tested negative for tumor markers and soluble interleukin-2 receptor (sIL-2R). Abdominal computed tomography revealed a 51-mm hypovascular mass that was slowly enhanced from the portal venous to the equilibrium phases, at the inferior extremity of the spleen. Abdominal magnetic resonance imaging showed a spoke-wheel pattern. Fluorodeoxyglucose positron emission tomography indicated a mild tumor accumulation, with a standardized uptake value max of 5.3. These results led to the suspicion of SANT, angioma, and angiosarcoma. Because the onset of malignant diseases could not be excluded, laparoscopic splenectomy was performed. A brown, round mass, without a capsule but with clear boundaries, was macroscopically observed on the cut surface. In addition, white fibrosis was found in the mass. Histopathological examination revealed nodular angioma lesions, and the proliferation of fibrotic interstices and inflammatory cells was observed between the lesions. Immunohistological examination revealed proliferation in the 3 types of narrow capillaries inside angiomatoid nodules;CD31+/CD34+/CD8-, CD31+/CD34-/CD8+, and CD31+/CD34-/CD8- cells; therefore, the patient was diagnosed with SANT. CONCLUSIONS: Here, we reported one patient who developed the typical symptoms of SANT. SANT is easily diagnosed by histopathological examination; however, its causes remain unknown. More cases with SANT are required for further analysis.

Clear Cell Carcinoma of the Hard Palate in an Adolescent Patient: A Case Report.

Clear cell carcinoma is an extremely rare low-grade malignancies occurring in less than 1% of salivary gland tumors. We report a case of clear cell carcinoma of the hard palate in a 15-year-old adolescent patient. She first noticed a palatal tumor at age 9, but the tumor was left untreated for 6 years. We performed incisional biopsy, but no definitive diagnosis was obtained. Excisional biopsy was then performed, and the histopathological diagnosis was clear cell carcinoma of the salivary gland. However, the tumor was exposed at the margin of the surgical specimen; thus, additional excision was performed. Five years after the treatment, no local recurrence or metastasis has been observed.

Incidentally Detected Microcarcinoma of Thyroid in Surgical Specimens of the Goiter in Pediatric Patient: A Case Report.

A 14 year-old girl with a previous medical history of cholecystic polyps was referred to our department with throat discomfort during swallowing. The cervical ultrasound and magnetic resonance imaging revealed a massive polycystic formation with a diameter of 45 × 24 × 31 mm consistent with a right lobe goiter. However, there were no findings for suspected malignancy. Hemithyroidectomy was performed and the specimen was sent for histopathological assessment. Hematoxylin-eosin staining of the right lower nodule showed variably-sized follicles consistent with adenomatous goiter. The right upper nodule showed a growth of relatively compact sized follicles　with a thick fibrous capsule. A satellite nodule lying outside of the tumor capsule was consistent with minimally invasive follicular thyroid microcarcinoma. We observed her without any additional treatment and no recurrence is seen at present.