Malignant pleural mesothelioma with heterologous elements.

AIMS: Malignant pleural mesothelioma with heterologous elements (such as osseous, cartilaginous or rhabdomyoblastic differentiation) is very rare. We tried to differentiate such mesothelioma cases from extraskeletal pleural osteosarcoma, which is very challenging. METHODS: We compared 10 malignant pleural mesotheliomas (three biphasic and seven sarcomatoid types) with two pleural osteosarcomas using clinicopathological and immunohistochemical methods, and also fluorescence in situ hybridisation (FISH) to examine for homozygous deletion of p16. RESULTS: The median age was 72 years for mesotheliomas, and 69 years for osteosarcoma. For mesothelioma, eight cases were male and two were female. Growth was diffuse in all mesothelioma cases except case 10, where it was localised, as it was for the two osteosarcomas. Among mesothelioma cases, 80% displayed osteosarcomatous and 60% chondromatous elements, while 10% exhibited rhabdomyoblastic ones. Immunohistochemical labelling for calretinin and AE1/AE3 was present in 8/10 and 7/10 mesotheliomas, respectively, but in only one osteosarcoma. Loss of methylthioadenosine phosphorylase was seen in 5/7 mesotheliomas. FISH analysis revealed homozygous deletion of p16 in 5/8 mesothelioma and 2/2 osteosarcoma. Median survival was 6.5 months after biopsy or surgical operation in mesothelioma, and 12 months after operation in osteosarcoma. CONCLUSIONS: Although median survival was longer for osteosarcoma than for malignant mesothelioma, we could not differentiate mesothelioma from pleural osteosarcoma on the combined basis of clinicopathological and immunohistochemical data, and FISH analysis. However, diffuse growth was more frequent in mesothelioma than in osteosarcoma.

[Cancer of the Ascending Colon Diagnosed at the Same Time as Breast Cancer Following Leukemia Treatment for Which Laparoscopic Surgery Was Performed-A Case Report].

An 83-year-old woman received 8 courses of chemotherapy(mogamulizumab)for adult T cell leukemia in the hematolo- gy department of our hospital, after which she achieved complete remission and was followed up with chemotherapy(VP/ MST: sobuzoxane/etoposide)as an outpatient. Later, diarrheal symptoms appeared, and detailed examinations led to a diagnosis of cancer of the ascending colon. Although no distal metastasis was found, breast cancer was also revealed in the C area of the right breast. The general status of the patient was favorable; thus, right pectoral muscle-conserving mastectomy and concomitant sentinel lymph node biopsy were performed through laparoscope-assisted extended right hemicolectomy. The postoperative course was favorable, and she was discharged on hospital day 7. The excised tumors were pathologically diagnosed as stageⅠ breast cancer and stage Ⅲa colorectal cancer. Chemotherapy(VP/MST)was administered without adjuvant chemotherapy. Presently, 18 months after surgery, complete remission of adult T cell leukemia has been maintained, without metastasis and recurrence of cancer of the ascending colon and breast cancer.

Diffuse Alveolar Septal Amyloidosis With Wild-Type Transthyretin With Spontaneous Lung Hematoma.

We experienced a mass formation in the right lower lobe in a patient with cardiac amyloidosis and heart failure. Radiologic findings of the chest showed no abnormality except a mass. The patient had non-valvular atrial fibrillation and was taking edoxaban. Surgical resection of the mass revealed a hematoma. Further pathologic evaluation revealed diffuse alveolar septal amyloidosis with transthyretin (ATTR). The genetic testing found no mutation in the TTR gene. Therefore, systemic wild-type TTR amyloidosis (ATTRwt) was confirmed. Alveolar septal ATTRwt is rare and patient had alveolar septal ATTRwt with spontaneous lung hematoma.

[PRIMARY SQUAMOUS CELL CARCINOMA OF THE PROSTATE: A CASE REPORT].

SQUAMOUS CELL CARCINOMA, prostate carcinoma, The patient was a 67-year-old man who visited our hospital with urge incontinence. His serum prostatic specific antigen level was normal (1.191 ng/mL). Digital rectal examination and magnetic resonance imaging suggested common prostatic carcinoma. A transperineal needle biopsy was performed, and the histological diagnosis was squamous cell carcinoma (SCC). The serum SCC-antigen level was normal, and the patient underwent a radical prostatectomy. Computed tomography 15 months later revealed multiple metastases in the lymph nodes. The patient underwent systemic chemotherapy using fluorouracil (5-FU) and cisplatin (CDDP). After 3 courses of chemotherapy, the multiple lymph node metastases could not be detected.

Expression of p16 in nodular fasciitis: an implication for self-limited and inflammatory nature of the lesion.

Nodular fasciitis (NF) is a self-limited tumorous lesion occurring in the upper as well as lower extremities. NF is composed of a proliferation of "primary culture"-like myofibroblastic cells with nuclear atypia and large nucleoli, thus mimicking sarcoma. NF harbors a promoter-swapping fusion gene containing the entire coding region of USP6 gene. Therefore, NF is a tumor with a fusion oncogene but self-limited. In order to explore why NF is self-limited, we examined whether myofibroblastic cells in NF express p16 protein, a gene product of CDKN2A gene and an inhibitor of cyclin-dependent kinase 4 (CDK4) as well as one of the hallmarks of cellular senescence. We immunohistochemically demonstrated strong and diffuse expression of p16 in myofibroblastic cells in 11 out of 15 cases of NF, and strong but partial expression in the remaining 4 of the cases. We also showed that 15 out of 15 cases of NF were immunohistochemically negative or only showed focal and faint immunopositivity for CDK4, murine double minute 2 (MDM2), and TP53 proteins. Furthermore, there were no significant changes in the copy number of CDKN2A, CDK4 and MDM2 genes, and no significant mutations in TP53, RB1, and CDKN2A genes in 1 case of NF selected. These data suggest a possible involvement in cell cycle arrest and presumed cellular senescence by p16 in myofibroblastic cells in NF. This may explain the self-limited as well as inflammatory nature of NF as a senescence-associated secretory phenotype.

Ectopic adrenocorticotropic hormone syndrome associated with olfactory neuroblastoma: acquirement of adrenocorticotropic hormone expression during disease course as shown by serial immunohistochemistry examinations.

Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is a condition of endogenous hypercortisolism sustained by an extrapituitary ACTH-secreting tumor. Olfactory neuroblastoma (ONB) is a rare malignant neoplasm of the sinonasal tract and is derived from the olfactory epithelium. Because the paranasal sinus is not a common site of EAS, the development of ONB in patients with EAS is rare. We herein report the first known case of ONB with acquirement of ACTH production during the clinical course as proven by immunohistochemistry. A 50-year-old man diagnosed with ONB was referred to our department in July 2015 because of hypokalemia, hyperglycemia, decreased eosinophil and granulocyte counts, and elevated serum levels of ACTH and cortisol. Although two previous ONB biopsy specimens (2011 and 2014) showed no ACTH immunoreactivity, a newly obtained specimen in August 2015 clearly showed ACTH immunoreactivity. This is the first case of ectopic ACTH syndrome associated with an ONB that acquired the ability to express ACTH during its clinical course as shown by serial immunohistochemical examinations.

An extremely rare case of primary malignancy in giant cell tumor of bone, arising in the right femur and harboring H3F3A mutation.

We experienced a case of primary malignancy in giant cell tumor of bone (GCTB), arising in the right femur and harboring H3F3A mutation. A 27-year-old Japanese male without any prior disease history complained of pain in his right hip joint and right lower limb. Radiological images revealed an osteolytic and multicystic lesion existing mainly at the proximal epiphysis of the right femur. Preoperative clinical diagnosis was GCTB, although irregular marginal sclerosis was an atypical radiographic finding for conventional GCTBs. Biopsy sample from the lesion revealed the coexistence of typical GCTB and undifferentiated high-grade round cell sarcoma. Despite of the wide local resection of the tumor with preoperative and postoperative chemotherapy, the patient died of multiple distant metastases of the tumor 9 months after the surgery. Since heterozygous H3F3A c. 103G>T (p. Gly34Trp) mutation was detected not only in the biopsy sample from the primary site with typical GCTB and high-grade sarcoma components but also in the resected material from the metastatic site with only pure high-grade sarcoma component, the tumor was considered originally derived from conventional GCTB and acquire malignant transformation to high-grade sarcoma. Thus, this is an extremely rare case of primary malignancy in GCTB and the first case report of primary malignancy in GCTB proved the presence of H3F3A mutation even in the sarcoma component.

Lung metastases in an atypical type A thymoma variant.

A 35-year-old woman had undergone extensive thymothymectomy for type A thymoma several years ago. However, two small lung nodules were found 4 and 5 years after surgery. After a partial lung resection to remove these nodules, pathology revealed that they were metastases of the type A thymoma. A pathological re-evaluation confirmed that the primary tumor had in fact been an atypical type A thymoma variant, a subset added to the WHO classification in 2015. Pathology should be re-evaluated in all patients diagnosed with type A thymoma before 2015 since they may have the more aggressive atypical type A thymoma variant.

A case of adenocarcinoma developed in the small intestine with chronic strongyloidiasis.

We experienced a case of intestinal strongyloidiasis complicated by jejunal carcinoma. A Japanese male in his 50s, who has a 7-year medical history of duodenal ulcers, complained of loss of appetite, nausea, vomiting and diarrhea. Computed tomography and gastroduodenal endoscopic examination revealed a stenosis of the duodenum. To remove the stenosis, gastric bypass surgery was performed. The pathological diagnosis of the resected jejunum was strongyloidiasis and well-differentiated adenocarcinoma with subserosal invasion and vascular infiltration. After administration of Ivermectin, Strongyloides stercoralis was not found in any biopsies or in the specimens of the intestine, which were resected due to cancer recurrence 2 years later. There are three possibilities for the reason of coexistence of S. stercoralis and adenocarcinoma: S. stercoralis caused the adenocarcinoma, S. stercoralis moved to the carcinoma, or just coincidence. Although it is difficult to prove a causal relationship between S. stercoralis and adenocarcinoma, this is the first report of adenocarcinoma developed in the jejunum with chronic strongyloidiasis. The number of nematode infections, including strongyloidiasis, is decreasing in Japan, although not worldwide. Therefore, it should be considered in patients with prolonged intestinal ulcers.

Primary undifferentiated small round cell sarcoma of the deep abdominal wall with a novel variant of t(10;19) CIC-DUX4 gene fusion.

We experienced a 38-year-old Japanese male with t(10;19) CIC-DUX4 -positive undifferentiated small round cell sarcoma in the deep abdominal wall. Three months before his first visit to our hospital, he noticed a mass in his right abdominal wall. Computed tomography on admission revealed a solid abdominal tumor 70×53mm in size and multiple small tumors in both lungs. The biopsy of the abdominal tumor revealed undifferentiated small round cell sarcoma, suggestive of Ewing sarcoma. Under the clinical diagnosis of Ewing-like sarcoma of the abdominal wall with multiple lung metastases, several cycles of ICE (ifosfamide, carboplatin and etoposide) therapy were performed. After the chemotherapy, the lung metastases disappeared, while the primary lesion rapidly grew. Additional VDC (vincristine, doxorubicin and cyclophosphamide) therapy was carried out without apparent effect. Although the surgical removal of the primary lesion was done, peritoneal dissemination and a huge metastatic liver tumor appeared thereafter. The patient died of disease progression two months after the surgery. The total clinical course was approximately one year, showing that the tumor was extremely aggressive. The tumor cells of the surgical specimen were positive for CD99, WT1, calretinin, INI1, ERG and Fli1 by immunohistochemistry. Fusion gene analyses using the frozen surgical material revealed negativity for EWSR1-Fli1, EWSR1-ERG and t(4;19) CIC-DUX4 fusions, but positivity for t(10;19) CIC-DUX4 fusion. Thus, we made a final pathological diagnosis of t(10;19) CIC-DUX4-positive undifferentiated small round cell sarcoma. To our knowledge, this is the 13th case of t(10;19) CIC-DUX4 undifferentiated small round cell sarcoma with precise clinicopathological information. Especially in our case, two types of t(10;19) CIC-DUX4 fusion transcripts were observed, both of which are in-frame and novel.

Primary hepatic leiomyosarcoma in a patient with autosomal dominant polycystic kidney disease.

Primary hepatic leiomyosarcoma is an extremely rare tumor. The diagnosis is difficult, and its etiologic factors have not been clarified. A 63-year-old woman with numerous cysts in her kidneys and liver was diagnosed with autosomal dominant polycystic kidney disease (ADPKD). Several members of her family also had ADPKD. She underwent treatment with tolvaptan to inhibit cyst growth and slow the decline in kidney function. Eight months after the start of the therapy, she was hospitalized with fatigue and fever of unknown origin. Diagnostic imaging showed a very large hepatic tumor, and histologic examination of a fine-needle biopsy specimen revealed the tumor to be malignant. Differentiation between carcinoma and sarcoma was difficult based on the histological findings. The tumor was thought to be excisable; therefore, hepatic resection was attempted. At the time of surgery, as the tumor had grown larger than when imaged, complete resection was impossible. However, a part of the tumor was resected. Histopathological and immunohistological examinations of the surgical specimen confirmed a primary hepatic leiomyosarcoma. Whether the tumor was associated with the presence of ADPKD remains unclear, however, this is the first report of the combination of these two diseases in a patient.

An unexpected skin ulcer and soft tissue necrosis after the nonconcurrent combination of proton beam therapy and pazopanib: A case of myxofibrosarcoma.

We herein report the case of a patient presenting with myxofibrosarcoma (MFS) who underwent treatment with surgery, proton beam therapy (PBT), and pazopanib. A 64-year-old male was diagnosed with MFS, which ranged from the posterior neck to the shoulder. Surgery was performed as an initial treatment; however, the primary tumor recurred 83 months after the initial treatment. We, therefore, administered PBT. Although most of the recurrent tumor disappeared after PBT, multiple lung metastases were identified 3 months after the completion of PBT. We initiated antiangiogenic treatment with pazopanib. Although long-term survival was achieved with the treatments, the patient suffered from a skin ulcer and soft tissue necrosis and eventually died of general prostration caused by infection, and complicated by pneumonia. Although PBT and pazopanib were effective for treating the local recurrence and lung metastases of MFS, respectively, clinicians must be cognizant of the fact that the combination of high-dose irradiation and angiogenesis inhibitors, even in nonconcurrent cases, can result in a severe skin ulcer and soft tissue necrosis.

Slow-Growing Mediastinal Grey Zone Lymphoma Originating From a Formerly Resected Multilocular Thymic Cyst.

We report a unique case of mediastinal grey zone lymphoma that was considered to originate from CD20+CD30+ Hodgkin cell-like cells associated with a multilocular thymic cyst that had been completely removed 4 years previously. In the formerly resected thymus, irregular-shaped cysts were observed, and large CD20+CD30+ Hodgkin cell-like cells proliferated in close association with the proliferating thymic epithelial cells. This case suggests the important role of thymic columnar epithelial cells in the proliferation of thymic B cells and the tumorigenesis of mediastinal grey zone lymphoma. Also, it suggests that mediastinal grey zone lymphoma can proliferate slowly in the very early stage.

A case of atypical type A thymoma variant.

BACKGROUND: An atypical type A thymoma variant was newly added to the WHO classification of type A thymoma family in 2015. CASE PRESENTATION: A 72-year-old female was present a large round mass in the anterior mediastinum. The radiological examination led to a preoperative diagnosis of non-invasive thymoma. Tumor resection was undertaken via median sternotomy. Complete removal of the mediastinal tumor was achieved. Pathological examination revealed that the tumor cells were spindle- and oval-shaped with atypia. Immunohistochemical work-up revealed that the tumor was type A thymoma. On the basis of these findings, the tumor was finally diagnosed to be an atypical type A thymoma variant. CONCLUSIONS: Preoperative diagnosis as atypical type A thymoma variant based on radiological examination is difficult. In case of atypical type A thymoma variant, a careful postoperative systemic follow-up should be done.

Pancreatic desmoid-type fibromatosis with beta-catenin gene mutation-Report of a case and review of the literature.

We experienced a rare case of pancreatic desmoid-type fibromatosis (DTF) in a 75-year-old Japanese woman. She was asymptomatic but routine examination including ultrasonography revealed a mass in the abdomen. For precise examination, she was referred to the regional hospital. Computed tomography showed that the mass was protruding anteriorly from the left-sided pancreas. Because of the enlargement of the mass lesion, distal pancreatectomy with splenectomy was performed after about 3 months. Macroscopically, the mass was encapsulated and approximately 8cm in diameter. Histological examination revealed that spindle or blunt stellate cells were proliferating in parallel or storiform fashion with myxoid and fibrous background. The tumor cells did not show prominent atypia and mitoses were rarely seen, suggesting that the tumor was low grade or borderline. Immunohistochemistry showed obvious nuclear staining of beta-catenin. Furthermore, analysis of beta-catenin gene revealed that the tumor had a typical missense mutation of threonine to alanine at colon 41 (T41A) in exon 3. These findings confirmed the pathological diagnosis of DTF of the pancreas. To the best of our knowledge, 18 cases of pancreatic DTF have been reported in the English literature and beta-catenin gene mutation had been examined in only one case among them. Thus, our case is the 19th pancreatic DTF and the second case with confirmed beta-catenin gene mutation.

'Papillary' solitary fibrous tumor/hemangiopericytoma with nuclear STAT6 expression and NAB2-STAT6 fusion.

This report describes clinicopathological findings, including genetic data of STAT6, in a solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) of the central nervous system in an 83-year-old woman with a bulge in the left forehead. She noticed it about 5 months before, and it had grown rapidly for the past 1 month. Neuroradiological studies disclosed a well-demarcated tumor that accompanied the destruction of the skull. The excised tumor showed a prominent papillary structure, where atypical cells were compactly arranged along the fibrovascular core ('pseudopapillary'). There was rich vasculature, some of which resembled 'staghorn' vessels. Mitotic figures were occasionally found. Whorls, psammoma bodies, or intra-nuclear pseudoinclusions were not identified. By immunohistochemistry, CD34 was strongly positive in the tumor cells, and STAT6 was localized in their nuclei. By reverse transcription-polymerase chain reaction (RT-PCR), an NAB2-STAT6 fusion gene, NAB2 exon6-STAT6 exon17, was detected, establishing a definite diagnosis of SFT/HPC. 'Papillary' SFT/HPC needs to be recognized as a possible morphological variant of SFT/HPC, and should be borne in mind in its diagnostic practice.

Epithelioid pleural mesothelioma concurrently associated with miliary pulmonary metastases and minimal change nephrotic syndrome - A hitherto undescribed case.

Malignant pleural mesothelioma (MPM) is the aggressive disease typically spreading along the pleural surface and encasing the lung, leading to respiratory failure or cachexia. Rare cases with atypical clinical manifestation or presentation have been reported in MPM. We experienced a unique case of MPM concurrently associated with miliary pulmonary metastases and nephrotic syndrome. A 73-year-old Japanese man with past history of asbestos exposure was referred to our hospital for the investigation of the left pleural effusion. Chest computed tomography showed thickening of the left parietal pleura. Biopsy specimen of the pleura showed proliferating epithelioid tumor cells, leading to the pathological diagnosis of epithelioid MPM with the aid of immunohistochemistry. After the diagnosis of MPM, chemotherapy was performed without effect. Soon after the clinical diagnosis of progressive disease with skull metastasis, edema and weight gain appeared. Laboratory data met the criteria of nephrotic syndrome, and renal biopsy with electron microscopic examination revealed the minimal change disease. Steroid therapy was started but showed no effect. Around the same time of onset of nephrotic syndrome, multiple miliary lung nodules appeared on chest CT. Transbronchial biopsy specimen of the nodules showed the metastatic MPM in the lung. The patient died because of the worsening of the general condition. To our knowledge, this is the first case of MPM concurrently associated with multiple miliary pulmonary metastases and nephrotic syndrome.

Primary central chondrosarcoma of long bone, limb girdle and trunk: Analysis of 174 cases by numerical scoring on histology.

The aims of this study were: (i) to elucidate clinicopathological characteristics of pcCHS of long bones (L), limb girdles (LG) and trunk (T) in Japan; (ii) to investigate predictive pathological findings for outcome of pcCHS of L, LG and T, objectively; and (iii) to elucidate a discrepancy of grade between biopsy and resected specimens. Clinicopathological profiles of 174 pcCHS (79 male, 95 female), of L, LG, and T were retrieved. For each case, a numerical score was given to 18 pathological findings. The average age was 50.5 years (15-80 years). Frequently involved sites were femur, humerus, pelvis and rib. The 5-year and 10-year disease-specific survival (DSS) rates [follow-up: 1-258 months (average 65.5)] were 87.0% and 80.4%, respectively. By Cox hazards analysis on pathological findings, age, sex and location, histologically higher grade and older age were unfavorable predictors, and calcification was a favorable predictor in DSS. The histological grade of resected specimen was higher than that of biopsy in 37.7% (26/69 cases). In conclusion, higher histological grade and older age were predictors for poor, but calcification was for good prognosis. Because there was a discrepancy in grade between biopsy and resected specimens, comprehensive evaluation is necessary before definitive operation for pcCHS.