Histopathological Composition of Thrombus in Acute Ischemic Stroke May Vary Even Within the Same Patient: A Preliminary Study Examining Clots According to Their Area of Retrieval.

Objective: Mechanical thrombectomy enables histopathological examination of clots in patients who have suffered acute ischemic strokes. Many studies have described about the relationship between the histopathological compositions of retrieved thrombi and imaging findings, clinical outcomes, and stroke etiology without consensus. In this study, we examined the histological composition of thrombi according to their retrieval site and methods. Methods: We divided retrieved clots into three parts (those retrieved from the proximal and distal parts of the stent retriever, and those aspirated through the guiding catheter) and then histopathologically analyzed their compositions by measuring the area occupied by red blood cells (RBCs), fibrin/platelets (F/Ps), and white blood cells (WBCs). Results: Each specimen showed various composition even within the same patient. For example, the area occupied by RBCs was 20.9% ± 12.1%, 30.5% ± 13.5%, and 41.3% ± 16.1% in the clot retrieved from the proximal and distal parts of the stent retriever, and those aspirated through the guiding catheter, respectively. Conclusion: Histopathological clot composition may vary even within the patient. Further research is needed to investigate more objective methods of histopathological analysis and their clinical significance.

A case of signet ring cell carcinoma and mucosa-associated lymphoid tissue lymphoma of the stomach diagnosed simultaneously via magnifying endoscopy with narrow-band imaging.

We present the case of a 57-year-old woman who experienced 3 weeks of intermittent tarry stools and epigastric pain. She had a 25-year history of smoking and a 12-year history of heavy alcohol consumption but had discontinued both 12 years prior. Laboratory investigations revealed elevated anti-H. Pylori IgG antibody levels. Conventional upper gastrointestinal endoscopy revealed two lesions. Magnifying endoscopy with narrow-band imaging showed the characteristic appearance of a diffuse-type gastric cancer 0-IIc lesion with a demarcation line and abnormal vessels ("wavy micro-vessels" and a "cork-screw pattern"). There was also "ballooning" of the crypts and a "tree-like vessel appearance" in an "unstructured area" characteristic of gastric mucosa-associated lymphoid tissue lymphoma with ulceration. Accurate target biopsies were obtained. We performed a laparoscopic total gastrectomy with D1 lymphadenectomy. Pathological examination revealed poorly differentiated stage I adenocarcinoma of the stomach with features of signet ring cell carcinoma as well as stage I mucosa-associated lymphoid tissue lymphoma. In conclusion, we encountered a case of co-existing diffuse-type gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. Magnifying endoscopy with narrow-band imaging was effective for diagnosing these two co-existing tumors and resulted in the collection of adequate biopsy specimens allowing for an accurate pathological diagnosis and optimal treatment.

[A Case of Progressive Sarcomatoid Renal Cell Carcinoma Treated with Second-Line Nivolumab after Surgery].

A 69-year-old man visited a local doctor for fever, pain in the left abdomen, and macroscopic hematuria. Computed tomography (CT) revealed hydronephrosis of the left kidney, and he was referred to our hospital. Detailed examinations suggested left-side pyonephrosis due to urothelial cancer, and left-side total nephroureterectomy was performed. Pathological diagnosis was sarcomatoid renal cell carcinoma. Sunitinib administration was started postoperatively for para-aortic lymph node metastasis, which disappeared. However, metastasis to the common iliac lymph node and liver appeared newly 11 months later. Nivolumab was started in combination with radiation thepapy for the lymph node metastases. The patient remains in a stable disease state as of 21 months after nivolumab administration.

Acquisition of resistance to androgen deprivation therapy in salivary duct carcinoma: A case report.

Salivary duct carcinoma is a relatively rare salivary cancer, and most cases are androgen receptor -positive. Salivary duct carcinoma growth is suggested to be androgen dependent, which can reportedly be controlled by androgen deprivation therapy. However, the effectiveness and underlying molecular mechanisms of androgen deprivation therapy for salivary duct carcinoma remain unknown. We report a salivary duct carcinoma case (65-year-old man) arising from the parotid gland with metastasis to the neck lymph nodes and lungs. Androgen deprivation therapy was performed according to the same protocol for prostate cancer treatment. Expression levels of androgen receptor and FOXA1 (forkhead box A1) were immunohistochemically analyzed before and after androgen deprivation therapy. Although the tumor volume was partially diminished during the first 3 months, acquired resistance to androgen deprivation therapy occurred. FOXA1 was not detected in parotid gland after androgen deprivation therapy, whereas androgen receptor expression was positive. FOXA1 expression might be related to acquired androgen deprivation therapy resistance in salivary duct carcinoma.

Extraventricular neurocytoma of the sellar region with spinal dissemination.

Extraventricular neurocytoma (EVN) is a rare tumor that mainly occurs in the cerebral hemispheres and spinal cord. Sellar neurocytoma is extremely rare, with only two previously reported cases. We report a sellar EVN in a 48-year-old man presenting with visual impairment. This tumor was partially resected. The residual tumor disappeared on MRI with adjuvant radiotherapy. However, 2 years later the tumor recurred with craniospinal dissemination, which is also very rare, with only four previously reported cases. The recurrent tumor showed atypical features with an MIB-1 LI score of 3 %. It is suggested that postoperative adjuvant radiation therapy with long-term follow-up is required for incompletely resected EVN.

Prognostic significance of programmed cell death-1-positive cells in follicular lymphoma patients may alter in the rituximab era.

Programmed cell death-1 (PD-1) is involved in one of the inhibitory pathways of the B7-cluster of differentiation (CD) 28 family; this pathway is known to be involved in the attenuation of T-cell responses and promotion of T-cell tolerance. PD-1 is known to negatively regulate T-cell receptor-mediated proliferation and cytokine production, lead to alternation in the tumor microenvironment. Although several studies have shown that high levels of PD-1-positive cells in follicular lymphoma (FL) patients influence their prognosis, those studies included patients treated without rituximab, and the prognostic impact of PD-1 positivity in the rituximab era (R-era) has not yet been elucidated. We retrospectively studied 82 patients with FL uniformly treated with standard R-CHOP therapy at six institutions between 2001 and 2009 (median follow-up for survivors: 55 months). We also collected and examined biopsy specimens for diagnosis with respect to PD-1 positivity. The PD-1 positivity was significantly higher in male patients and patients with high beta-2 microglobulin (B2M ≥ 3.0) (P = 0.03 and 0.003, respectively). Three-year progression free survival (PFS) and overall survival (OS) were 60% and 86%, respectively. By univariate analysis, elevated LDH (P = 0.07) worsened PFS. Male gender (P = 0.03), high FLIPI score (P = 0.05), and high B2M levels (P = 0.08) worsened OS. Multivariate analysis detected no significant prognostic factors, including PD-1 positivity. However, in male subgroup, high levels of PD-1-positive cells were found to be a prognostic factor for PFS. Addition of rituximab might have altered the prognostic impact of PD-1-positive cells.

[Lymphoepithelioma-like carcinoma（ LELC） of the lung].

A 77-year-old woman was admitted to our hospital with abnormal chest shadow detected on a medical checkup. Chest computed tomography(CT)showed a well-defined tumor in the upper lobe of the right lung. On positron emission tomography by fluorodeoxyglucose(FDG),the tumor revealed to be positive. We performed right upper lobectomy with hilar and mediastinal lymph node dissection. The histopathological diagnosis was lymphoepithelioma-like carcinoma (LELC). In the past 25-years, 41 cases have been reported in Japan. The average age is 64 years old, including 25 male cases and 16 female cases. Among these cases, more than half were in the early resectable stage.

[Human pulmonary dirofilariasis].

The patient was a 60's-year-old man, who was incidentally pointed out a coin lesion in the right lung by chest radiogram. Chest computed tomography showed a round-shaped, well defined nodule of 2.5 cm in size in the right S1. Positron emission tomography did not show the accumulation of fluorodeoxyglucose in the nodule. We considered the tumor to be benign, but the patient chose surgical treatment. Partial resection of the lung was performed by thoracoscopic surgery. Histopathological diagnosis was human pulmonary dirofilariasis.

[Systemic neurolymphomatosis complicated in diffuse large B-cell lymphoma].

A 73-year-old woman was diagnosed with diffuse large B-cell lymphoma of the uterus (Stage IVB). After 3 courses of CHOP therapy, right abducens nerve paralysis appeared and was diagnosed as central nervous system infiltration with lymphoma cells. Although partial remission was obtained by chemotherapy with methotrexate, numbness and muscle weakness of all four limbs appeared asymmetrically and progressed subacutely. Nerve conduction velocity examination revealed mononeuritis multiplex, but we could not reach a final diagnosis. Steroid pulse therapy, chemotherapy including high-dose methotrexate, and radiation therapy were ineffective. On autopsy, histological examination of the peripheral nerves revealed systemic neurolymphomatosis.

Gastrointestinal stromal tumor of the rectal mesentery.

We report a case of gastrointestinal stromal tumor (GIST) arising from the rectal mesentery. GIST of the large intestine is a rare tumor that accounts for only 0.1% of all colorectal cancers. The patient presented to our hospital with constipation and abdominal distension. Computed tomography (CT) revealed a huge mass in the pelvic cavity, and laparotomy disclosed diffuse peritoneal dissemination from the primary tumor. Radiochemotherapy was commenced, but the patient became too ill to complete it and died of the disease 2 months after surgery. A large high-grade tumor with diffuse dissemination was recognized as an indicator of poor survival in this patient.