We herein present a rare case of a papillary fibroelastoma on the pulmonary valve. A 66-year-old female underwent a graft replacement of the ascending aorta and an aortic valve replacement. Subsequent biannual checks have been performed as a follow up to surgery. An echocardiography, 3 years post surgery, revealed a growing mass, 13 mm in diameter, which was attached to the pulmonary valve. Upon surgery, the mass, which lacked a stalk, was found attached to the right semilunar cusp of the pulmonary valve. The cusp was resected with the mass in order to ensure a complete resection, and as we were unable to repair the pulmonary valve, it needed to be replaced with a mechanical valve. The pathological examination of the resected mass resulted in our diagnosis of a papillary fibroelastoma. The patient is now doing well 2 years after the surgery without any recurrence of the tumor.

Myelodysplastic syndromes/myeloproliferative neoplasm (MDS/MPN) is a type of myeloid neoplasm where at least one hematopoietic lineage exhibiting cytopenia clinically coexists with other (s) exhibiting hypercytosis. There is ineffective erythropoiesis and bone marrow coexistence of at least one hematopoietic lineage morphologically characterized by dysplasia of blood cells and other (s) characterized by pronounced proliferation. At a molecular level, various abnormalities have been identified that overlap with related diseases, and a prerequisite for MDS/MPN diagnosis includes ruling out various hematopoietic tumors and reactive conditions. Therefore, a multilateral approach involving clinical findings, morphology, and molecular biology is needed. Herein, we introduce the pathological features of MDS/MPN and the relationship between molecular abnormalities and morphological characteristics.

One of the main molecular features of myeloproliferative neoplasms (MPNs) is the high frequency of JAK2V617F or CALRexon 9 mutations. The mouse models driven by these mutations suggest that they are the direct cause of MPNs and that the expression levels of mutated genes define the disease phenotype. The function of MPN-initiating cells was also elucidated using these mouse models. Furthermore, these mouse models play important roles as disease models to investigate the effects and mechanisms of action of therapeutic drugs such as JAK2 inhibitors and interferon α against MPNs. The mutation landscape of hematological tumors has already been clarified using next-generation sequencing technology, and future research on the importance of the functional analysis of mutant genes in vivo should be emphasized. Thus, it is necessary to promote rapid genetic modification techniques such as genome editing.

A 56-year-old woman was diagnosed with rectal cancer and liver metastases(Stage IV), and underwent low anterior resection and laparoscopic partial hepatectomy. The patient received adjuvant chemotherapy(mFOLFOX6 for 24 weeks), but developed multiple lung metastases 11 months later. Before undergoing a pulmonary resection, the patient presented with acute small bowel obstruction. Abdominal computed tomography showed small bowel stenosis due to a tumor, and we suspected peritoneal metastases from the rectal tumor. We performed partial resection of the small intestine, and histopathological examination revealed a primary small bowel tumor. The patient was discharged to her home without complications, and later underwent pulmonary resections for bilateral lung metastases. We usually suspect that small bowel obstruction is due to peritoneal metastases in patients with advanced colorectal tumors, but must consider the rare possibility of a separate primary small bowel tumor, especially in patients with a solitary lesion. We report a rare primary small bowel tumor after FOLFOX treatment in a patient with Stage IV rectal cancer.

The patient was a woman in her 60's with an 11-month history ofpersistent epigastralgia and abdominal distension, without abnormal findings on upper endoscopy, abdominal ultrasonography, and abdominal computed tomography in other hospitals. She presented to our hospital with a complaint off requent vomiting; abdominal CT indicated intussusception in the jejunum due to a small intestinal tumor, and laparoscopic exploration and partial jejunectomy were performed. The histopathological diagnosis was tub1>tub2>pap, pT4(SE), pN1, pPM0, pDM0, pStage III A. She was treated with oral chemotherapy( S-1)and developed no recurrence 7 months after surgery. Laparoscopic exploration was useful to detect intussusception in the jejunum due to small intestinal adenocarcinoma.

A man in his 50s with small cell lung cancer received amrubicin as the fourth-line therapy from August 201X-1. Serum phosphorus levels before treatment were normal at 2.9mg/dL, but grade 2 hypophosphatemia(2.1mg/dL)was observed at the beginning of the 2nd course. He underwent laryngoplasty after the 4th course. Retreatment was initiated in June 201X due to disease progression. After reinitiating treatment, the disease developed to grade 3 hypophosphatemia. As we identi- fied lower levels(1.1mg/dL)at the start of the 10th course, a pharmacist proposed oral phosphate therapy to the attending physician, which we administered. After then, the levels improved to 2.2mg/dL; thus, oral phosphate therapy was interrupted. However, because of a decline in serum phosphorus levels to grade 3, we administered the therapy again, and observed favorable improvement. For hypophosphatemia in this case, general reasons in clinical practice were not applicable; thus, amrubicin is considered to be a most possible cause.

A 78-year-old man who developed metastatic liver and lung cancer after undergoing surgery for rectal and sigmoid colon cancer was treated with TAS-102 as fourth-line chemotherapy. He developed high fever and dyspnea and was referred to the emergency room 16 days after receiving the first course of TAS-102. Chest X-ray and computed tomography examinations showed bacterial pneumonia. He was treated with tazobactam/piperacillin, but developed severe dyspnea 4 days later. A diffuse ground-glass appearance was observed in both the lungs on chest X-ray examination, and drug-induced interstitial pneumonitis was suspected. Oxygenation and respiratory support were immediately administered, and steroid pulse therapy with methylprednisolone at 1,000mg/day was initiated. His symptoms and radiographic findings dramatically improved. The TAS102-J003 trial, a double-blind phase 2 trial, showed that interstitial pneumonitis occurs at a rate of only 0.9%, but can lead to severe complications, as observed in the present case. The possibility of interstitial pneumonitis should always be considered when a patient develops a fever and respiratory disorder during treatment containing TAS-102.

A 61-year-old man was referred to the urology department in our hospital with gross hematuria and hydro nephrosis. Cystoscopy revealed a smooth mass lesion in his bladder, and a transurethral biopsy was performed. Signet ring cell carcinoma was found in the submucosa. Upper gastrointestinal endoscopy revealed an ulcerated lesion in his gastric body. Biopsy specimens obtained from the ulcerated lesion showed signet ring cell carcinoma. No other primary lesions were detected using colonoscopy, gallium scintigraphy, or computed tomography of the chest. He was ultimately diagnosed with advanced gastric cancer with bladder metastasis. He was prescribed combination chemotherapy of cisplatin and tegafur, gimeracil, oteracil potassium, and trastuzumab. After 2 courses of chemotherapy, there was a decrease in the size of both the gastric and bladder lesions. There was also a significant decrease in the tumor marker levels. He is currently alive after 7 courses of chemotherapy.

A 24-year-old man with acute lymphoblasticleukemia underwent allogeneicperipheral blood stem cell transplantation (allo-PBSCT)from a human leukocyte antigen-matched sibling after myeloablative conditioning, with a regimen including total body irradiation(TBI)(12 Gy/6 fractions), 6 years ago. The patient developed extensive chronic graft-versus-host disease(cGVHD)of the skin, mouth, liver, and gut four months after allo-PBSCT. Treatment with cyclosporine and prednisolone was necessary to control the cGVHD. Six years after allo-PBSCT, the patient experienced odynophagia and was diagnosed with cervical esophageal squamous cell carcinoma(cT1bN1M0, cStage II B). Because we considered laryngeal preservation, risk of anastomotic leakage, and infection related to the operation, the patient was planned to receive chemoradio- therapy with 5-fluorouracil and cisplatin. Regarding irradiation, the patient received radiotherapy(50.4 Gy/28 fractions)for a primary tumor and lymph node without an elective nodal area. The patient achieved complete response and remained disease- free without any treatment-related complications for 3 years.

The patient was a 42-year-old man who presented with dysphagia.Upper gastrointestinal endoscopy revealed a protruding lesion in the lower thoracic esophagus.Pathological analysis of the lesion showed squamous cell carcinoma.Laboratory data showed leukocytosis(21,200/mL)despite no evidence of infection, and the serum levels of granulocyte colony-stimu- lating factor(G-CSF)were elevated to 283 pg/mL.We diagnosed him with esophageal squamous cell carcinoma(Lt, type 1, cT4N4M0, cStage IV a).After administering 2 courses of docetaxel plus cisplatin plus S-1(DCS)as neoadjuvant chemotherapy, the patient underwent surgery.The pathological diagnosis was pType 2, T2, N4, M0, pStage IV a. G-CSF immunostaining was positive in tumor cells.After the surgery, the number of leukocytes and serum G-CSF levels decreased to within normal limits.Adjuvant chemotherapy was administered.

Case 1 involved a 75-year-old woman with breast cancer and diffuse large B-cell lymphoma(DLBCL).Although we initially administered the R-CHOP regimen, the breast tumor increased in size and surgery had to be performed.After surgery, the R-CHOP regimen was re-initiated and DLBCL achieved clinical complete response.Case 2 involved a 74-year-old woman with breast cancer and gastric MALT lymphoma.After administration of rituximab and H. pylori eradication, a therapeutic effect was achieved in the lymphoma.A docetaxel and FEC regimen was continuously administered and surgery was performed. Case 3 involved a 62-year-old woman with breast cancer and follicular lymphoma.She presented with a history of DLBCL treatment.We performed mastectomy and sentinel lymph node biopsy, which revealed metastasis of breast cancer, and axillary lymph node dissection was subsequently performed.Considering the pathological stage, adjuvant chemotherapy was needed.We selected the TCH regimen based on her past treatment.In conclusion, it is necessary to treat patients with double presentation of breast cancer and malignant lymphoma through cooperation with different departments.

A 73-year-old woman noticed a mass in her right breast about 1 year ago and consulted our hospital for an enlarged mass of about 10 cm in diameter.She was diagnosed with locally advanced triple negative breast cancer, and we initiated S-1 treatment as neoadjuvant chemotherapy.After 4 chemotherapy courses, computed tomography showed that the primary tumor had shrunk.Therefore, right mastectomy and axillary dissection were performed, and UFT was administered after surgery.She is currently alive with no recurrence 18 months after surgery.

A 65-year-old woman who had liver cirrhosis(Child-Pugh class B)due to hepatitis C infection was diagnosed with hepatocellular carcinoma with hepatic vein invasion, portal vein tumor invasion, and lung metastasis. No recommended treatment was noted in the clinical practice guidelines for hepatocellular carcinoma with vascular invasion in patients with Child- Pugh class B liver cirrhosis. After initiating arterial injection chemotherapy, marked decreases in tumor size of lung metastasis, vascular invasion, and primary liver cancer were observed. Based on our experience and previous reports, hepatic arterial infusion chemotherapy was considered valuable for hepatocellular carcinoma with vascular invasion, even in patients with Child-Pugh class B liver cirrhosis.

Development of immunotherapy, especially checkpoint inhibitors, dramatically improved the prognosis of some malignancies. However, problems on the occurrence of severe adverse effects and limited responses to these checkpoint inhibitors remain. Recently, tumor infiltrating lymphocytes(TILs)are the predictive markers of immunotherapies based on clinical evidence. The proportion of cytotoxic T cells in the tumor has been reported to affect the antitumor effect. TILs in the tumor are thought to be controlled by the interaction between cancer and tumor microenvironment. As a cause of tumor immunosuppression, cancer-associated fibroblasts(CAFs)play the main role in the tumor microenvironment. We considered the strong involvement of tumor microenvironment, particularly the role of CAFs, and reported the interaction between CAFs and proliferation, invasion, angiogenesis, and resistance in the conventional therapy. The correlation between CAFs and tumor immunity and the immunosuppression promoted by CAFs were also evaluated. Their effects will be reported in our future studies.

The case presented herein was a 70-year-old woman who had no compliant, but had a mass in the lower part of the right lobe of the thyroid detected by ultrasound (US). The US image of the tumor, measuring 13 mm in diameter, showed a low and heterogeneous internal echo level with calcification and an irregular margin. The tumor appeared to extend to the adjacent sternothyroid muscle, and cervical lymph node swelling was detected in a computer tomography (CT) image, but no metastatic lesion was found by positron emission tomography (PET)-CT. In a fine needle aspiration cytology of the tumor, papillary thyroid carcinoma was suggested because of the atypical epithelial cells having some changes other than intranuclear inclusion bodies. A subtotal thyroidectomy and central neck lymph node dissection were performed. The excised tumor was histologically composed of irregular nests or sheets of atypical squamoid epithelial cells with some ductal structures that leached to the sternothyroid muscle and involved the right lower parathyroid gland. Carcinoma showing thymus-like differentiation (CASTLE) was diagnosed histopathologically and immunohistochemically with the following immunohistochemical results: Cluster of differentiation 5 (CD5) (+), tumor protein p63 (p63) (+), KIT proto-oncogene receptor tyrosine kinase (c-KIT(CD117)) (+), thyroglobulin (-), and thyroid transcription factor-1 (TTF-1) (-). CASTLE is a rare carcinoma of the thyroid that architecturally resembles thymic epithelial tumors. Many CASTLE patients have been misdiagnosed as other carcinomas, such as anaplastic carcinoma, poorly differentiated carcinoma or squamous cell carcinoma of the thyroid. Immunohistochemical examination, including CD5 played an important role in the final diagnosis of CASTLE, although the distinction from diagnosis as squamous cell carcinoma or mucoepidermoid carcinoma in Hematoxylin-Eosin staining was challenging in our case. Nodal metastasis and perithyroidal tumor extension of CASTLE can predict its worse prognosis. Thus, at least careful follow-up studies are mandatory in cases of CASTLE.

A 74-year-old male who was receiving endocrine therapy for prostate cancer, with multiple bone and lymph node metastases (T2bN1M1 Stage D2), underwent follow-up computed tomography (CT). The CT revealed multiple liver metastases, a high serum CEA level, and an unchanged PSA level. Upper gastrointestinal endoscopy showed an elevated lesion with mucosal erosion on the lesser curvature of the middle gastric corpus, revealed to be a metastatic prostate cancer lesion following immunohistochemical confirmation. This case demonstrates the potential for gastric metastases in patients with advanced prostate cancer and high serum CEA levels.

The patient was a 74-year-old man who had undergone surgery for rectal cancer 9 years before and had developed left lung metastasis(S3)3 years and 4 months prior to admission. He had received video assisted left lung wedge resection. He presented with a growing nodular lesion close to the remaining left lung margin and elevated serum carcinoembryonic antigen(CEA)levels, and underwent open extended segmentectomy. The chest drain tube was removed on 3rd post-operative day, but he developed left pneumothorax on 4th post-operative day and a computed tomography(CT)scan revealed a cystic lesion 5.0 cm in size at the base of his left lung. Revision surgery was performed on 8th post-operative day. A pulmonary cyst on the diaphragmatic surface of the lung(S10)was found and location of the air leak was confirmed in the same area. Following wedge resection of the cyst-containing region, the leak ceased completely. Rapid manifestation of a newly formed pulmonary cyst during the acute post-operative period is rare.