A rare case of resection of a mucinous cystic neoplasm originating from the extrahepatic bile duct with cholangioscopic imaging.

A 29-year-old woman was admitted to our hospital for examination of obstructive jaundice and an extrahepatic bile duct lesion. Contrast-enhanced computed tomography revealed a 20 mm cystic lesion with a thin external capsule in the common hepatic duct. Cholangioscopy revealed translucent oval masses with capillary vessels attached to the bile duct walls. The surface was mostly smooth yet partially irregular with redness, suggesting that the masses were epithelial neoplasms. Histological findings of cholangioscopy-guided targeted biopsies of the mass showed subepithelial spindle cell proliferation with no atypical epithelium. The patient underwent an extrahepatic bile duct resection to confirm the pathological diagnosis. Immunohistochemistry of surgical specimens revealed that the spindle cells were positive for estrogen and progesterone receptors. Finally, the cystic lesion with ovarian-like stroma was diagnosed as a mucinous cystic neoplasm with low-grade intraepithelial neoplasia. This is the first report of cholangioscopic imaging of a biliary mucinous cyctic neoplasm. Cholangioscopic imaging can be helpful in the differential diagnosis of biliary neoplasms and in the determination of treatment strategies.

Inflammatory Rhabdomyoblastic Tumor: Clinicopathologic and Molecular Analysis of 13 Cases.

Inflammatory rhabdomyoblastic tumors (IRMTs) are newly recognized skeletal muscle tumors with uncertain malignant potential. We investigated 13 IRMTs using clinicopathologic, genetic, and epigenetic methods. The cohort included 7 men and 6 women, aged 23 to 80 years (median, 50 years), of whom 2 had neurofibromatosis type 1. Most tumors occurred in the deep soft tissues of the lower limbs, head/neck, trunk wall, and retroperitoneum/pelvis. Two tumors involved the hypopharyngeal submucosa as polypoid masses. Eight tumors showed conventional histology of predominantly spindled cells with nuclear atypia, low mitotic activity, and massive inflammatory infiltrates. Three tumors showed atypical histology, including uniform epithelioid or plump cells and mitotically active histiocytes. The remaining 2 tumors demonstrated malignant progression to rhabdomyosarcoma; one had additional IRMT histology and the other was a pure sarcoma. All 11 IRMTs without malignant progression exhibited indolent behavior at a median follow-up of 43 months. One of the 2 patients with IRMTs with malignant progression died of lung metastases. All IRMTs were positive for desmin and PAX7, whereas myogenin and MyoD1 were expressed in a subset of cases. Targeted next-generation sequencing identified pathogenic mutations in NF1 (5/8) and TP53 (4/8). All TP53 mutations co-occurred with NF1 mutations. TP53 variant allele frequency was much lower than that of NF1 in 2 cases. These tumors showed geographic (subclonal) strong p53 immunoreactivity, suggesting the secondary emergence of a TP53-mutant clone. DNA methylation-based copy number analysis conducted in 11 tumors revealed characteristic flat patterns with relative gains, including chromosomes 5, 18, 20, 21, and/or 22 in most cases. Widespread loss of heterozygosity with retained biparental copies of these chromosomes was confirmed in 4 tumors analyzed via allele-specific profiling. Based on unsupervised DNA methylation analysis, none of the 11 tumors tested clustered with existing reference entities but formed a coherent group, although its specificity warrants further study.

Metastatic pulmonary pleomorphic carcinoma replaced by a granulomatous lesion after spontaneous regression and PD-1 blockade-induced regression: can epithelioid granuloma be a histological hallmark of cancer immunity?

Immune checkpoint inhibitors (ICIs) for various types of malignancy, including non-small-cell lung cancer, have improved prognosis in some cases. Granuloma formation after ICI administration suggests a tumor antigen-specific cytotoxic T cell response with abundant interferon-gamma production, which can be used to estimate the curative effect of ICIs. In this report, we present a case with a resected lung lesion, clinically suspected to be lung cancer, that consisted of a granulomatous lesion. A tumor was also found in the duodenum that was presumed to be derived from the pulmonary pleomorphic carcinoma. Duodenal tumor cells highly expressed PD-L1, suggesting PD-1/PD-L1 axis-mediated immune escape. As expected, pembrolizumab induced a complete response for the duodenal lesion. Interestingly, in histopathological analysis, the duodenal lesion was also replaced by an epithelial granuloma and multinucleated giant cells. We conclude that autoimmunity regressed the untreated primary lung lesion spontaneously, while the metastatic duodenal lesion responded to PD-1 blockade. Tumor-associated epithelioid granulomas, even before ICI administration, may be an important pathological finding indicating an immune response with interferon-gamma production by cytotoxic T cells to the tumor.

Usefulness of cell block examination for the cytological diagnosis of thoracic SMARCA4-deficient undifferentiated tumor: A case report.

SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a high-grade malignant neoplasm showing undifferentiated or rhabdoid morphology that significantly involves the thorax of adults. It has been reported as SMARCA4-deficient thoracic sarcoma or SMARCA4-deficient non-small cell lung carcinoma according to the findings of immunohistochemical and genetic studies. We report a case of thoracic SMARCA4-UT for which cell block analysis and immunohistochemical staining were useful for the final diagnosis. A 51-year-old man had a chief complaint of left back pain and visited our hospital for further examination. Cytological examination of a left pleural effusion was performed and we also made a cell block of the pleural effusion. Cytological examination revealed polyhedral to round tumor cells. The tumor cells appeared singly or formed loosely cohesive clusters. The nuclei were round to oval, enlarged, and sometimes eccentric with prominent nucleoli with irregular borders. The nuclear chromatin was unevenly distributed. The cytoplasm was vacuolar to eosinophilic. There were no characteristic structures of tumor cells. The cell block revealed many single or loosely cohesive round to epithelioid cells. Some tumor cells often exhibited eccentrically located nuclei and lightly eosinophilic cytoplasm, showing a rhabdoid morphology. On immunohistochemistry, the tumor cells were positive for SOX-2 and they demonstrated significantly reduced SMARCA4 (BRG1) expression; SMARCA2 (BRM) and SMARCB1 (INI1) expression were retained. Accordingly, we made a diagnosis of SMARCA4-UT. This case demonstrates the importance of performing histological and immunohistochemical analysis using cell blocks for immediate diagnosis.

Usefulness of SynCAM3 and cyclin D1 immunohistochemistry in distinguishing superficial CD34-positive fibroblastic tumor from its histological mimics.

Superficial CD34-positive fibroblastic tumor (SCPFT) is a fibroblastic/myofibroblastic soft tissue tumor of rarely metastasizing intermediate malignancy. Some recent studies have described a relationship between SCPFT and PRDM10-rearranged soft tissue tumor (PRT) based on SynCAM3 and PRDM10 expression on immunohistochemistry. We performed CD34, cytokeratin AE1/AE3, SynCAM3, and PRDM10 immunohistochemistry in SCPFT and its histological mimics, including myxoinflammatory fibroblastic sarcoma (MIFS), superficially localized myxofibrosarcoma (MFS), and undifferentiated pleomorphic sarcoma. We also examined cyclin D1 expression because it is expressed in MIFS and MFS. We conducted fluorescence in situ hybridization (FISH) of PRDM10 rearrangement in SCPFT cases. On immunohistochemistry, only SCPFT showed strong and diffuse SynCAM3 expression. SCPFT also exhibited strong nuclear and weak cytoplasmic cyclin D1 expression, which was similar to that observed in MIFS. Two of five SCPFT cases exhibited nuclear PRDM10 expression. FISH revealed PRDM10 split signals in 44% and 24% of tumor cells in two SCPFT cases showing nuclear PRDM10 expression on immunohistochemistry, respectively. A minority of non-SCPFT cases showed focal SynCAM3 expression, but a combination of SynCAM3 and cyclin D1 in addition to CD34 and cytokeratin AE1/AE3 may be useful for the differential diagnosis of SCPFT and its histological mimics.

Severe thrombocytopenia and anemia as an initial presentation of breast cancer: A case report.

Breast cancer patients with bone marrow metastasis (BMM) having profound thrombocytopenia and anemia are rare and there is no definitive treatment guideline. We present a case of successful initial treatment with anti-disseminated intravascular coagulation therapy and endocrine therapy, followed by chemotherapy to avoid deterioration of severe thrombocytopenia and anemia.

Diagnostic utility of CSF1 immunohistochemistry in tenosynovial giant cell tumor for differentiating from giant cell-rich tumors and tumor-like lesions of bone and soft tissue.

BACKGROUND: Tenosynovial giant cell tumor (TSGCT) is a benign fibrohistiocytic tumor that affects the synovium of joints, bursa, and tendon sheaths and is categorized into localized TSGCT (LTSGCT) and diffuse TSGCT (DTSGCT). LTSGCT and DTSGCT are characterized by recurrent fusions involving the colony-stimulating factor 1 (CSF1) gene and its translocation partner collagen type VI alpha 3 chain. The fusion gene induces intratumoral overexpression of CSF1 mRNA and CSF1 protein. CSF1 expression is a characteristic finding of TSGCT and detection of CSF1 mRNA and CSF1 protein may be useful for the pathological diagnosis. Although there have been no effective anti-CSF1 antibodies to date, in situ hybridization (ISH) for CSF1 mRNA has been performed to detect CSF1 expression in TSGCT. We performed CSF1 immunohistochemistry (IHC) using anti-CSF1 antibody (clone 2D10) in cases of TSGCT, giant cell-rich tumor (GCRT), and GCRT-like lesion and verified its utility for the pathological diagnosis of TSGCT. METHODS: We performed CSF1 IHC in 110 cases including 44 LTSGCTs, 20 DTSGCTs, 1 malignant TSGCT (MTSGCT), 10 giant cell tumors of bone, 2 giant cell reparative granulomas, 3 aneurysmal bone cysts, 10 undifferentiated pleomorphic sarcomas, 10 leiomyosarcomas, and 10 myxofibrosarcomas. We performed fluorescence ISH (FISH) for CSF1 rearrangement to confirm CSF1 expression on IHC in TSGCTs. We considered the specimens to have CSF1 rearrangement if a split signal was observed in greater than 2% of the tumor cells. RESULTS: Overall, 50 of 65 TSGCT cases, including 35 of the 44 LTSGCTs and 15 of the 20 DTSGCTs, showed distinct scattered expression of CSF1 in the majority of mononuclear tumor cells. MTSGCT showed no CSF1 expression. Non-TSGCT cases were negative for CSF1. FISH revealed CSF1 rearrangement in 6 of 7 CSF1-positive cases on IHC. On the other hand, FISH detected no CSF1 rearrangement in all CSF1-negative cases on IHC. Thus, the results of IHC corresponded to those of FISH. CONCLUSION: We revealed characteristic CSF1 expression on IHC in cases of TSGCT, whereas the cases of non-TSGCT exhibited no CSF1 expression. CSF1 IHC may be useful for differentiating TSGCTs from histologically mimicking GCRTs and GCRT-like lesions.

[Accuracy Evaluation of Air Kerma-area Product of Over-couch-type X-ray Fluoroscopic System].

PURPOSE: The purpose of this study was to evaluate the accuracy of incident air kerma (Ka,r) and air kerma-area product (PKA) displayed on over-couch-type X-ray fluoroscopic systems by comparing them with the measured values. METHODS: An ionizing chamber was placed at the patient entrance reference point to measure the Ka,r. The PKA was calculated by multiplying the Ka,r by the irradiation area. These measured values were compared with the displayed values. RESULTS: The differences between measured and displayed Ka,r and PKA were less than ±35%, which was the criteria of the Japanese Industrial Standards (JIS). However, the accuracy of the displayed values differed depending on the manufacturer and the device. CONCLUSION: Although no error exceeding the JIS criteria was observed, it is necessary to understand the characteristics of the X-ray fluoroscopic systems related to displayed dose and to manage the systems by performing dose measurements periodically.

Atypical spindle cell/pleomorphic lipomatous tumor with a sarcomatous component showing high mitotic activity and Ki-67 labeling index: report of a unique case mimicking dedifferentiated liposarcoma.

Atypical spindle cell/pleomorphic lipomatous tumor (ASPLT) is a new entity of benign adipocytic tumor that spans a wide spectrum of histology from adipocytic to spindle cell/pleomorphic tumors. The latter non-adipocytic component rarely shows sarcomatous features although ASPLTs are not thought to dedifferentiate. A 78-year-old woman with ASPLT in the left thigh had a sarcomatous component with high mitotic activity and Ki-67 labeling index (LI) mimicking dedifferentiated liposarcoma. The adipocytic component consisted of various-sized adipocytic cells with few lipoblasts. The sarcomatous component consisted of a fascicular proliferation of atypical spindle cells with scattered large bizarre and multinucleated giant cells. Mitotic figures including atypical mitoses were frequently observed. Immunohistochemically, the tumor cells were positive for cluster of differentiation 34 but not mouse double minute 2 homolog (MDM2), cyclin-dependent kinase 4 (CDK4), or retinoblastoma (Rb) protein. Ki-67 LI in the sarcomatous component reached 40%. MDM2 and CDK4 genes were not amplified and 13q14 including the RB1 locus was deleted according to fluorescence in situ hybridization. The patient is alive with no evidence of local recurrence or distant metastasis 3.5 years after surgery. As ASPLT may exhibit morphological variation, it is important to rule out dedifferentiated liposarcoma with careful pathological examination.

Prognostic usefulness of a modified risk model for solitary fibrous tumor that includes the Ki-67 labeling index.

BACKGROUND: Predicting the prognosis of patients with solitary fibrous tumor (SFT) is often difficult. The prognostic risk models developed by Demicco et al. are now the standard for evaluating the risk of SFT metastasis in the current World Health Organization classification of soft tissue and bone tumors. METHODS: In this study, we examined the prognostic usefulness of a modified version of the Demicco risk models that replaces the mitotic count with the Ki-67 labeling index. We compared the three-variable and four-variable Demicco risk models with our modified risk models using Kaplan-Meier curves based on data for 43 patients with SFT. RESULTS: We found a significant difference in metastasis-free survival when patients were classified into low-risk and intermediate/high-risk groups using the three-variable (P = 0.022) and four-variable (P = 0.046) Demicco models. There was also a significant difference in metastasis-free survival between the low-risk and intermediate/high-risk groups when the modified three-variable (P = 0.006) and four-variable (P = 0.022) models were used. CONCLUSION: Modified risk models that include the Ki-67 labeling index are effective for prediction of the prognosis in patients with SFT.

Atypical Cogan's Syndrome Mimicking Giant Cell Arteritis Successfully Treated with Early Administration of Tocilizumab.

A 49-year-old Japanese man with a 2-month history of a fever, headache, and bilateral conjunctival hyperemia was admitted. His condition fulfilled the giant cell arteritis classification criteria (new headache, temporal artery tenderness, elevated ESR) and atypical Cogan's syndrome (CS) with scleritis and sensorineural hearing loss (SNHL). The interleukin (IL)-6 serum level was extremely high. Two weeks after his insufficient response of SNHL and scleritis to oral prednisolone, we administered tocilizumab (TCZ); rapid improvements in scleritis and SNHL occurred. Early IL-6 target therapy can help prevent irreversible CS-induced sensory organ damage.

[A Simple Measurement Method for Verifying the Accuracy of the Displayed Dose on an Over-couch-type X-ray Fluoroscopic System].

The purpose of this study was to establish a simple measurement method to verify the accuracy of incident air kerma (Ka, r) and air kerma area product (PKA) displayed on an over-couch-type X-ray fluoroscopy system. A dosimeter was located at the patient entrance reference point, and the irradiation field size was set to 10×10 cm. A lead plate was placed on the couchtop to protect the image receptor, and the duration of fluoroscopy was set to 1 min. The Ka, r was measured with the proposed method and the Japanese Industrial Standards (JIS) method on three X-ray fluoroscopy units of different manufactures. The effect of backscattered X-rays from the lead plate was calculated using Monte Carlo methods. The errors of the displayed Ka, r and PKA to the measured Ka, r and PKA with our proposed method were calculated. There was no significant difference in the measured Ka, r between the proposed method and the JIS method in all units. The effect of backscattered X-ray was ≤0.5%. The errors of displayed Ka, r and PKA to those measured were in the range of 3.4 to 15.7% and -4.1 to 20.3%, respectively, which met the tolerance for accuracy of ±35% in accordance with the JIS method. We found that our proposed method was simple and that the accuracy of measured values was comparable to that of the JIS method.

Identification of characteristic subepithelial surface granulomatosis in immune-related adverse event-associated enterocolitis.

Immune checkpoint inhibitors (ICIs) have provided an additional treatment option for various types of human cancers. However, ICIs often induce various immune-related adverse events (irAEs). Enterocolitis is a major irAE with poorly understood histopathological characteristics. In this study, we retrospectively investigated the histopathology of colon tissue samples from 17 patients treated with ICIs. There were two major histological patterns of colitis: an ulcerative colitis-like pattern and a graft vs host disease-like pattern. Although these two patterns of colitis were mutually exclusive, both patterns often showed a characteristic that we call "subepithelial surface granulomatosis" (SSG), which has not been reported in other types of colitis. SSG was found even in colon tissue without symptoms or endoscopic findings of colitis. Given the increasing reports of sarcoid reaction or exacerbation of tuberculosis after treatment with ICIs, granuloma formation could be a histological hallmark of systemic immune activation by ICIs. Although statistical significance was not obtained, probably because of the small sample size, SSG may be a surrogate biomarker of systemic anticancer immune activation. We propose that a prospective study with larger sample size be performed.

Myoepithelioma of soft tissue and bone, and myoepithelioma-like tumors of the vulvar region: Clinicopathological study of 15 cases by PLAG1 immunohistochemistry.

We demonstrated the clinicopathological findings of 13 myoepitheliomas of soft tissue and bone (MESTBs) and two myoepithelioma-like tumors of the vulvar region (MELTVRs), focusing on the association between nuclear atypia and clinical course, and the utility of immunohistochemistry (IHC) of pleomorphic adenoma gene 1 (PLAG1) for the pathological diagnosis of these tumors. Of the 13 MESTBs, eight, one and four cases exhibited mild, moderate and severe nuclear atypia, respectively. Two cases with venous invasion showed severe nuclear atypia and both died of advanced disease. Two MELTVR cases showed moderate nuclear atypia and had no evidence of disease after surgery. On IHC, 12 of 13 (92.3%) MESTBs showed PLAG1 immunoreactivity and none of the MELTVRs expressed PLAG1. In addition, MELTVRs showed loss of INI1 expression. In contrast, all MESTBs retained INI1 expression. Fluorescence in situ hybridization detected EWSR1, FUS and PLAG1 rearrangement in 5 (38.5%), 0 (0%) and 2 (15.4%) of the 13 MESTBs, respectively. No EWSR1, FUS and PLAG1 rearrangement were observed in the METLVRs. In conclusion, MESTBs with both severe nuclear atypia and venous invasion would be indicative of malignant potential. PLAG1 might be a useful IHC marker in MESTB diagnosis.

Pathological evaluation of the accuracy of a fluorescence spectroscopy system for detecting parathyroid glands.

PURPOSE: A fluorescence-based technique for the detection of parathyroid glands (PGs) intraoperatively was previously reported. The technique was based on the phenomenon in which PGs emit autofluorescence when exposed to near-infrared light and we undertook an evaluation to consider the pathological accuracy of the method. METHODS: The study comprised 17 patients (18 specimens) who underwent thyroid surgery at Kushiro City General Hospital between November 2018 and June 2019. We searched for PGs intraoperatively using a fluorescence spectroscopy system and evaluated the pathological accuracy of the system. We statistically evaluated the clinical factors associated with the accuracy of the system, including age, gender, body mass index, laterality, disease state, renal function, and comorbidity. RESULTS: Eighteen specimens were evaluated pathologically, with 13 specimens confirmed as PGs. These were evaluated as "true positive," giving a positive predictive value of 72.2% (13/18). Among the false-negative cases, one specimen was a metastatic lymph node in a patient with papillary thyroid carcinoma. There was a significant difference in the true-positive rates between malignant (25%) and benign (85.7%) disease (P = 0.044). CONCLUSION: We consider that this technique is useful, however, we have to exercise care in malignant cases as the true-positive rate may be low.

Does the extension of the type of hysterectomy contribute to the local control of endometrial cancer?

OBJECTIVE: To examine the necessity and sufficiency of different types of hysterectomy for the surgical treatment of endometrial cancer. METHODS: This was a multicenter collaborative study conducted by 11 institutions. Among patients with stage I-III endometrial cancer who underwent surgery as the initial treatment (only chemotherapy was provided if adjuvant therapy was needed) from 2001 to 2012, we retrospectively examined the type of hysterectomy, clinicopathological factors, recurrence rate over a maximum period of 5 years, and the site of recurrence. The local recurrence rate was examined by univariate and multivariate analyses. RESULTS: Among 1335 patients, 982 (73.6%) underwent simple hysterectomy (SH) and 353 (26.4%) underwent modified radical hysterectomy (mRH) and were observed for a mean duration of 51.8 months. No significant difference was observed in the rate of local recurrence between the SH and mRH groups (p = 0.928). In multivariate analysis, clinicopathological factors independently associated with localized recurrence included postmenopausal status [hazard ratio (HR) 5.036, 95% confidence interval (CI) 1.506-16.841, p = 0.009], with stages II (HR 3.337, 95% CI 1.701-6.547, p < 0.001) and III (HR 2.445, 95% CI 1.280-4.668, p = 0.007), vs stage I and histological type 2 (HR 1.610, 95% CI 0.938-2.762, p = 0.001). CONCLUSIONS: For endometrial cancer patients requiring surgery, the selection of a more extensive type of hysterectomy did not reduce the rate of local recurrence. Therefore, there is little significance in performing mRH in such cases.

Spindle cell rhabdomyosarcoma in a lumbar vertebra with FUS-TFCP2 fusion.

A 70-year-old woman developed severe buttock pain that progressed to a walking disturbance. Radiographs and computed tomography scans revealed an osteolytic lesion with osteosclerosis extending from the body to the arch of the fifth lumbar vertebra. Magnetic resonance imaging showed multinodular masses in the fifth lumbar vertebral body extending into the spinous processes and right transverse process. The masses were hypointense to isointense on T1-weighted images and hypointense to hyperintense on T2-weighted images. Histologic examination of biopsy specimens showed destruction of the trabecula of the vertebral bone by a fascicular and solid proliferation of spindle tumor cells and scattered rhabdomyoblasts, in a fibrotic background. The tumor cells were immunoreactive for keratins, vimentin, desmin, MyoD1, myogenin, and anaplastic lymphoma kinase. Fluorescence in situ hybridization detected split signals for FUS and TFCP2 in 80% and 64% of the tumor cells, respectively, suggesting FUS-TFCP2 fusion. Reverse transcription-polymerase chain reaction revealed a FUS-TFCP2 fusion. The final diagnosis was spindle cell rhabdomyosarcoma of a lumbar vertebra with a FUS-TFCP2 fusion. A spindle cell rhabdomyosarcoma with a FUS-TFCP2 fusion in a vertebral bone is rare and should be differentiated from metastatic carcinoma, particularly in the elderly.

Imprint cytology of biphenotypic sinonasal sarcoma of the paranasal sinus: A case report.

Biphenotypic sinonasal sarcoma (BSNS) is a rare low-grade spindle cell sarcoma that predominantly affects middle-aged women with multiple tumors in the sinonasal tract. BSNS shows biphenotypic expression of neural and myogenic markers on immunohistochemistry (IHC) with a specific chimeric PAX3-MAML3 fusion. The cytological features of BSNS have so far not been reported. Here, we describe a case of BSNS including findings of imprint cytology, histology, IHC, and genetic analysis. A 30-year-old woman presented with a nodular tumor that completely occupied the ethmoid sinus. The tumor was resected and submitted for imprint cytology, which revealed relatively bland spindle tumor cells that had mildly enlarged oval to spindle-shaped nuclei with fine nuclear chromatin and a thin nuclear rim in a clear background. Nucleoli were inconspicuous and there was no significant nuclear atypia and pleomorphism. These cytological findings were consistent with the histology of low-grade spindle cell sarcoma in BSNS. On IHC, the tumor cells were focally positive for S-100 protein and α-smooth muscle actin; nuclear ß-catenin expression was also seen. PAX3 split signals were detected in 52% of tumor cells by fluorescence in situ hybridization. Reverse transcriptase-polymerase chain reaction also identified a chimeric PAX3-MAML3 fusion gene. Based on these findings, we diagnosed the tumor as BSNS. Our findings revealed that a relatively bland spindle cell cytology with a clear background is a characteristic feature of BSNS. BSNS should therefore be differentiated from benign and bland-appearing malignant spindle cell tumors and the combination of cytology, histology, IHC, and genetic analysis facilitates the diagnosis of BSNS.