Castleman disease and mimickers: Clinicopathological findings of atypical lymphoproliferative disorders associated with autoimmune disease.

Atypical lymphoproliferative disorders (LPDs) related with autoimmune disease (AID) show marked clinicopathological diversity, which are defined as three distinct clinicopathological subtypes such as those resembling Castleman disease (CD), atypical paracortical hyperplasia with lymphoid follicles (APHLF), and atypical lymphoplasmacytic and immunoblastic proliferation (ALPIB). We studied excisional biopsy specimens from 31 patients with atypical LPDs associated with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and Sjögren syndrome (SjS). The lesions in these 31 cases were classified into 6 (19.4%) cases resembling CD, 14 (45.2%) cases of APHLF, and 11 (35.5%) cases of ALPIB. Five cases (83.3%) resembling CD were in the active stage with systemic symptoms and multicentric lymphadenopathy. Thirteen cases (92.9%) of APHLF showed systemic symptoms, multicentric lymphadenopathy and abnormal laboratory findings. Histologic findings for cases resembling CD were rare in patients with RA and SjS. In AID patients, histologic findings for cases resembling CD or APHLF findings correlated with disease activity and multicentric lymphadenopathy. Six cases (54.5%) of ALPIB were in the active phase with systemic symptoms and multicentric lymphadenopathy. ALPIB tended to be unrelated to AID activity, especially in the majority of patients with no abnormal laboratory findings. Atypical LPDs associated with AID is a group of diseases that may be overdiagnosed and overtreated. The diagnosis of atypical LPDs associated with AID requires an understanding of the histological findings as well as a comprehensive assessment of the presence of systemic symptoms, the distribution of lymphadenopathy, and abnormal laboratory findings.

Mixed adenoneuroendocrine carcinoma of the non-ampullary duodenum with mismatch repair deficiency: a rare case report.

A non-ampullary duodenal mixed adenoneuroendocrine carcinoma (MANEC), consisting of a conventional adenocarcinoma and a neuroendocrine carcinoma (NEC), is exceedingly rare. Moreover, mismatch repair (MMR) deficient tumors have recently attracted attention. The patient, a 75-year-old woman with epigastric pain and nausea, was found to have a type 2 tumor of the duodenum, which was diagnosed on biopsy as a poorly differentiated carcinoma. A pancreaticoduodenectomy specimen showed a well-defined 50 × 48 mm tumor in the duodenal bulb, which was morphologically composed of glandular, sheet-like, and pleomorphic components. The glandular component was a tubular adenocarcinoma, showing a MUC5AC-positive gastric type. The sheet-like component consisted of homogenous tumor cells, with chromogranin A and synaptophysin diffusely positive, and a Ki-67 index of 72.8%. The pleomorphic component was diverse and prominent atypical tumor cells proliferated, focally positive for chromogranin A, diffusely positive for synaptophysin, and the Ki-67 index was 67.1%. The sheet-like and pleomorphic components were considered NEC, showing aberrant expression of p53, retinoblastoma, and p16. Notably, all three components were deficient in MLH1 and PMS2. We diagnosed a non-ampullary duodenal MANEC with MMR deficiency. This tumor has a unique morphology and immunohistochemical profile, and is valuable for clarifying the tumorigenesis mechanism of a non-ampullary duodenal MANEC.

Cryptococcal Prostatitis Forming Caseous and Suppurative Granulomas Diagnosed by Needle Biopsy: A Case Report.

Cryptococcal granulomatous prostatitis is extremely rare, and there have been few reports of its diagnosis by prostate needle biopsy. The patient, an 81-year-old man, was receiving immunosuppressive treatment for rheumatoid arthritis. He had an oropharyngeal ulcer, and it was diagnosed alongside a methotrexate-related diffuse large B-cell lymphoma. A systemic imaging examination revealed a prostatic tumor-like mass clinically suspected to be prostatic cancer, and a needle biopsy was performed. The biopsy specimen showed various types of inflammatory cell infiltration, and suppurative granuloma and caseous granuloma were observed. Both granulomas showed multiple round and oval organisms that were revealed with Grocott methenamine silver staining. Acid-fast bacilli were not detected by Ziehl-Neelsen staining. We histologically diagnosed granulomatous prostatitis caused by Cryptococcus infection. Caseous granulomas often develop in the prostate after bacillus Calmette-Guerin immunotherapy for bladder cancer, although the possibility of cryptococcal granulomatous prostatitis should also be considered.

Antitumor effect of dimethyl itaconate on thymic carcinoma by targeting LDHA-mTOR axis.

AIMS: Thymic carcinoma is a rare type of cancer without an established standard pharmaceutical treatment. This study investigated the antitumor effect of dimethyl itaconate (DI), a cell-permeable derivative of itaconate, on human thymic carcinoma cell line. MAIN METHODS: Human thymic carcinoma cell line Ty82 was used to evaluate the effect of DI on cell viability. Western blotting and immunohistochemistry were performed to determine the molecular mechanism of antitumor effects of DI on Ty82. KEY FINDINGS: DI suppressed cell growth and promoted apoptosis of Ty82. The suppressive effect of DI on Ty82 was mediated by the downregulation of lactate dehydrogenase A (LDHA), and the subsequent decrease in the activity of mechanistic target of rapamycin (mTOR). DI exhibited synergistic antitumor effects with a specific inhibitor of large neutral amino acid transporter 1 (LAT1), an amino acid transporter currently being investigated as a novel target for cancer therapy. SIGNIFICANCE: Our findings demonstrate that DI is a novel potential strategy for thymic carcinoma treatment.

Plasmacytoid urothelial carcinoma of renal pelvis with positive zinc finger E-box-binding homeobox 1: a case report.

BACKGROUND: The tumor transformation mechanism of a plasmacytoid urothelial carcinoma remains unexplained. We describe the case of a plasmacytoid urothelial carcinoma of the renal pelvis in which the expression of zinc finger E-box-binding homeobox 1 (ZEB1), a key nuclear transcription factor in an epithelial-mesenchymal transition, is involved in tumor transformation. CASE PRESENTATION: The patient had a left nephrectomy with the clinical diagnosis of left pelvic renal cancer. The resected specimen showed that the tumor surface comprised a noninvasive papillary urothelial carcinoma with the carcinoma in situ, and the invasive area comprised a plasmacytoid urothelial carcinoma characterized by the presence of single dyscohesive malignant cells that resembled plasma cells in a loose myxoid stroma. The noninvasive urothelial carcinoma was positive for cytokeratin and E-cadherin, and negative for vimentin and ZEB1. In contrast, the invasive plasmacytoid urothelial carcinoma was positive for cytokeratin and also vimentin and ZEB1, and negative for E-cadherin. Additionally, this component was immunoreactive for CD138 and CD38 that are immunohistochemical markers for plasma cells. CONCLUSION: We suggest that ZEB1 is involved in the plasmacytoid transformation by repressing the E-cadherin in a plasmacytoid urothelial carcinoma.

Metachronous bilateral breast metastases of a lung neuroendocrine tumor: A case report.

Breast metastases of primary lung neuroendocrine tumors are rarely reported. The current report presents the case of a 41-year old female with no history of smoking who initially underwent surgery for a breast fibroadenoma, during which a neuroendocrine tumor of the right lung was detected via chest X-ray. The patient underwent surgery for the tumor and developed right breast nodules after adjuvant chemotherapy. Histological and immunohistochemical examinations of biopsies from these nodules indicated breast metastasis of the primary lung neuroendocrine tumor. The patient underwent mastectomy of the right breast but subsequently developed metastases in the left breast, for which local radiotherapy was administered. The observed metachronous bilateral breast metastases indicated that the contralateral breast should be considered during an investigation of metastasis.

A case of spindle cell dominant histiocytic sarcoma showing a complete remission after first-line chemotherapy with doxorubicin and ifosfamide.

Histiocytic sarcoma (HS), an extremely rare malignancy, usually follows a progressive time course, and patients die within two years of diagnosis. At present, there is no consensus for effective chemotherapy. We report the case of a 54-year-old man who presented with low back pain and left hip joint pain. Imaging for the pain revealed multiple lesions in the mediastinum, vertebral bodies, and left ilium. Biopsies of the mediastinal and vertebral lesions yielded a diagnosis of soft tissue sarcoma. He received standard chemotherapy for sarcoma with doxorubicin and ifosfamide, as the initial pathological diagnosis was soft tissue sarcoma. This is called AI therapy and commonly used for soft tissue sarcoma. Palliative radiation therapy to the left iliac lesion was added for pain control. Complete remission (CR) was achieved after two courses of AI therapy. Subsequent immunopathological examination revealed that the tumor was spindle cell dominant HS. CR was maintained for more than three years. To the best of our knowledge, this is the first report that a CR was achieved by AI therapy as first-line treatment for spindle cell dominant HS, combined with focal bone palliative irradiation. AI therapy could be an effective option as chemotherapy for HS.

Prognostic impact of a tumor-infiltrating lymphocyte subtype in triple negative cancer of the breast.

BACKGROUND: Tumor-infiltrating lymphocytes (TILs) have recently been reported as an important factor in the tumor microenvironment and influence the growth and progression of cancer. However, the relationship between immune cell subpopulations, such as CD4+, CD8+, and FOXP3+, in breast cancer, especially in triple negative carcinoma (TNC), remains unclear. METHODS: The subjects were 107 patients with TNC that were surgically resected at Dokkyo Medical University Hospital between 2006 and 2018. The expression of CD4+, CD8+, and FOXP3+ was evaluated in TILs and expressed as the numbers of positive cells. RESULTS: Univariate analysis revealed that the TILs were not prognostically significant. In multivariate analyses, increased infiltration of intratumoral (i) CD4+ TILs was found to have a good prognosis in relapse-free survival (RFS). In contrast, a high stromal CD8+ TILs level was found to be a favorable prognostic factor in RFS (p = 0.038) and overall survival (OS) (p = 0.046). A low sFOXP3 + TILs level was significantly associated with favorable RFS (p < 0.001) and OS (p = 0.029). CONCLUSIONS: The present study demonstrated no difference in TILs and survival in TNC. However, there was a significant correlation in prognosis with levels of iCD4+, sCD8+, and sFOXP3 + TILs in TNC. The difference in TNC clinical outcome may be due to the subtype of the infiltrating TILs.

Fluvastatin is effective against thymic carcinoma.

AIMS: Thymic carcinoma is a rare epithelial tumor, for which, optimal pharmacotherapeutic methods have not yet been established. To develop new drug treatments for thymic carcinoma, we investigated the effects of fluvastatin-mediated pharmacological inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) on thymic carcinoma. MAIN METHODS: Thymic carcinoma tissue was surgically excised and HMGCR expression was assessed by immunohistochemistry. Ty82 human thymic carcinoma cells were treated with fluvastatin (1-10 µM) and their growth was monitored. KEY FINDINGS: HMGCR was expressed on carcinoma cells but not on normal epithelial cells in thymic tissue. Inhibition of HMGCR by fluvastatin suppressed cell proliferation and induced the death of Ty-82 human thymic carcinoma cells. Fluvastatin mediated its antitumor effects by blocking the production of geranylgeranyl-pyrophosphate (GGPP), an isoprenoid that is produced from mevalonate and binds to small GTPases, which promotes cell proliferation. SIGNIFICANCE: Fluvastatin showed marked antitumor effects on thymic carcinoma. The results suggest that the statin has clinical benefits in thymic carcinoma management.

Impact of tumor infiltrating lymphocytes and lymphoid follicle formation on patient survival following surgery for lung squamous cell carcinoma.

BACKGROUND: Tumor infiltrating lymphocytes (TILs) are known to correlate with the prognosis of patients affected by a variety of cancer types. We evaluated TILs in patients who underwent surgery for lung squamous cell carcinoma (SCC). METHODS: Specimens obtained from patients during resection of lung SCC were examined for TIL density, lymphoid follicle formation, PD-L1 expression, and the appearance of regulatory T cells (Tregs). RESULTS: We enrolled 72 patients who underwent surgery for SCC (TIL grades 0, 1, and 2: 29, 18, and 25, respectively). Lymphoid follicles were observed in 13 (18.1%) patients and 8 were positive for Tregs, which were always observed in association with lymphoid follicles (P < 0.001). Multivariate analysis revealed that lymphoid follicle formation, the appearance of Tregs, pathological stage, and pleural invasion were independent prognostic factors related to overall survival, whereas TIL density and PD-L1 expression were not. CONCLUSION: SCC patients with lymphoid follicle formation accompanied by Tregs show poor survival following lung resection surgery.

L-Type Amino Acid Transporter 1 Immunoreactivity as a Possible Diagnostic and Prognostic Marker of Thymic Carcinoma.

L-type amino acid transporter 1 (LAT1) functions to transport large neutral amino acids, such as leucine, isoleucine, valine, phenylalanine, tyrosine, tryptophan, methionine, and histidine. These amino acids are essential for cell growth and proliferation. Many studies have demonstrated LAT1 expression in various types of cancer, and its high expression level was associated with poor prognosis. However, the significance of LAT1 expression in thymic epithelial tumors is controversial. We conducted this retrospective study to investigate the LAT1 immunoreactivity in thymic epithelial tumors and its impact on prognosis. We analyzed 32 patients with thymoma and 14 patients with thymic carcinoma who underwent surgery at our institute. Immunohistochemical analysis was performed using formalin-fixed paraffin-embedded surgical tissues and an anti-LAT1 polyclonal antibody. We thus found that LAT1 immunoreactivity was undetectable in all of the thymoma specimens, regardless of the subtypes of thymoma. By contrast, LAT1 immunoreactivity was consistently detected in the cytosol of thymic carcinoma cells; namely, all 14 thymic carcinoma specimens demonstrated LAT1 immunoreactivity in the cytosol. Among these 14 thymic carcinoma specimens, four carcinoma specimens also showed LAT1 immunoreactivity in the cell membrane. Survival analysis indicated that the thymic carcinoma with the LAT1 membrane signal was associated with poor prognosis, compared with the specimens with the LAT1 cytosol signal. We therefore propose that LAT1 is expressed in the cytosol of thymic carcinoma cells, which could be a diagnostic marker of thymic carcinoma. Moreover, LAT1 expression in the cell membrane is a prognostic marker of thymic carcinoma.

Nuclear Morphometry of Lung Squamous Cell Carcinomas in Cytologic Study.

BACKGROUND: The nuclei of most cancer cells in histopathologic preparations differ from normal nuclei and vary individually in size, shape, and chromatin pattern. Although the cytologic characteristics of squamous cell carcinoma (SCC) of the lung have been described, quantification of the cytologic features has not been established. METHODS: Cytologic investigations were performed on bronchial brushings or washings, or fine-needle aspirates. We analyzed the nuclear area (NA) of 50 tumor cells in 32 patients with SCC of the lung and 50 bronchial epithelial cells in 20 patients with no evidence of malignancy including inflammatory lesions. RESULTS: The NA of tumor cells (102.4 ± 26.2 µm2) was significantly larger than that of bronchial epithelial cells (64.1 ± 16.9 µm2) (P = 0.001). The receiver operating characteristic (ROC) curve analysis showed that an NA cutoff level of 86 µm2 had a sensitivity of 75% and specificity of 88% to detect malignant components. CONCLUSION: We conducted quantitative analyses of NA in SCC using cytologic specimen, NA was a useful parameter for evaluation of differential diagnosis between SCC and non-malignancies even in cytologic specimens.

Characteristic Histological Findings of Asymptomatic EBV-associated Lymphoproliferative Disorders in Tonsils.

Recently, an in situ hybridization (ISH) and immunohistochemical study demonstrated that Epstein-Barr virus (EBV) infection may be involved in tonsillar hypertrophy and recurrent tonsillitis in children and young adolescents. The present study was based on 630 consecutive specimens from tonsillectomies performed at the Dokkyo University School of Medicine between 2002 and May 2017. Clinical findings were obtained from hospital records. Histologically, a "pale clear zone" was characterized by hyperplastic germinal centers with ill-defined borders and interfollicular expansion. Immunohistologically, the majority of immunoblasts were CD20-positive, whereas medium to large lymphoid cells usually expressed CD3. Among 14 lesions, numerous EBV-encoded small RNA (EBER)-positive cells were detected in 10. In 7 of these 10 lesions, EBER-positive cells were detected in germinal centers as well as in the interfollicular area. Based on our results, the "pale clear zone" suggests asymptomatic EBV infection of the tonsil. The present study demonstrated that "pale clear zones" should be taken into consideration when diagnosing asymptomatic EBV-associated LPDs in the tonsils of children and young adolescents as well as in middle-aged patients.

Intraoperative frozen section diagnosis of bile duct margin for extrahepatic cholangiocarcinoma.

AIM: To evaluate the usefulness of frozen section diagnosis (FSD) of bile duct margins during surgery for extrahepatic cholangiocarcinoma (CCA). METHODS: We retrospectively analyzed 74 consecutive patients who underwent surgery for extrahepatic CCA from 2012 to 2017, during which FSD of bile duct margins was performed. They consisted of 40 distant and 34 perihilar CCAs (45 and 55 bile duct margins, respectively). The diagnosis was classified into three categories: negative, borderline (biliary intraepithelial neoplasia-1 and 2, and indefinite for neoplasia), or positive. FSD in the epithelial layer, subepithelial layer, and total layer was compared with corresponding permanent section diagnosis (PSD) postoperatively. Then, association between FSD and local recurrence was analyzed with special reference to borderline. RESULTS: Analysis of 100 duct margins revealed that concordance rate between FSD and PSD was 68.0% in the total layer, 69.0% in the epithelial layer, and 98.0% in the subepithelial layer. The extent of remaining biliary epithelium was comparable between FSD and PSD, and more than half of the margins lost > 50% of the entire epithelium, suggesting low quality of the samples. In FSD, the rate of negative margins decreased and that of borderline and positive margins increased according to the extent of the remaining epithelium. Diagnostic discordance between FSD and PSD was observed in 31 epithelial layers and two subepithelial layers. Alteration from borderline to negative was the most frequent (20 of the 31 epithelial layers). Patients with positive margin in the total and epithelial layers by FSD demonstrated a significantly worse local recurrence-free survival (RFS) compared with patients with borderline and negative margins, which revealed comparable local RFS. Patients with borderline and negative margins in the epithelial layer by PSD also revealed comparable local RFS. These results suggested that epithelial borderline might be regarded substantially as negative. When classifying the status of the epithelial layer either as negative or positive, concordance rates between FSD and PSD in the total, epithelial, and subepithelial layers were 95.0%, 93.0%, and 98.0%, respectively. CONCLUSION: During intraoperative assessment of bile duct margin, borderline in the epithelial layer can be substantially regarded as negative, under which condition FSD is comparable to PSD.