MRI and CT features of a malignant myoepithelioma of the scrotum : A case report and literature review

Malignant myoepithelioma of the scrotum is extremely rare. We report the case of a 51-year-old man with malignant myoepithelioma of the scrotum, wherein computed tomography and magnetic resonance imaging revealed a lobulated soft tissue mass with calcification, cystic component, and solid component with gradual contrast enhancement on dynamic contrast-enhanced scans. The patient presented with scrotal induration, and there was no elevation of tumor markers and no evidence of a metastatic lesion on computed tomography and magnetic resonance imaging. Histopathological examination of the resected scrotal specimen confirmed a well-circumscribed solid tumor with septa, a small area of hemorrhage, and necrosis. The subsequent diagnosis was malignant myoepithelioma of the scrotum. This case shows that scrotal malignant myoepithelioma might appear as a well-defined lobulated mass with cystic regions. We conjecture that the enhancement pattern and apparent diffusion coefficient values can be potential markers for scrotal myoepithelial tumors

Human bone marrow VCAM-1+ macrophages provide a niche for reactive and neoplastic erythropoiesis

Resident bone marrow macrophages provide a microenvironment for erythropoiesis, forming erythroblastic islands (EBIs) via adhesion molecules. In this study, we examined vascular cell adhesion molecule-1 (VCAM-1) expression in human bone marrow specimens using immunohistochemistry. VCAM-1 was strongly expressed in CD169+ macrophages in EBIs and weakly in sinusoidal vascular endothelial cells. In reactive erythropoiesis, including hemolytic and megaloblastic anemia, the extended cytoplasm of VCAM-1+ CD169+ macrophages circumscribed the erythroid cells. The strong affinity between VCAM-1+ macrophages and erythroid cells was also observed in polycythemia vera (PV), essential thrombocythemia (ET), and chronic myelogenous leukemia (CML). VCAM-1 density was significantly higher in PV than in ET and CML (p < 0.001), and correlated with blood erythrocyte count in all three neoplasms (p < 0.001). In ET, the VCAM-1 density was higher in cases with the JAK2 mutation than with the CALR mutation. In myelodysplastic syndrome with erythroid predominance but unclear EBI formation, punctate VCAM-1+ cytoplasmic processes of macrophages were seen between erythroblasts, similar to those seen between granulocytic precursors in CML, suggesting incomplete contact of VCAM-1+ macrophages with dysplastic erythroid cells. These results suggest that VCAM-1+ macrophages create a niche for reactive and neoplastic erythropoiesis and may be a therapeutic target in PV

Sphingosine-1-phosphate receptor 1 expression in angiosarcoma : Possible role in metastasis and a potential therapeutic target

Sphingosine-1-phosphate (S1P) is a potent lipid mediator that has been implicated in the migration of lymphocytes and endothelial cells through S1P receptors. S1PR1 is strongly expressed in angiosarcoma, a malignant tumor of endothelial cell origin that has a high propensity for metastasis and poor prognosis; however, the pathological significance of S1PR1 expression is not clear. In this study, we investigated the effect of S1PR1 modulation on cell migration, and examined its potential role as a therapeutic target against metastatic dissemination of angiosarcoma. S1PR1 expression in the human angiosarcoma cell line MO-LAS was assessed by immunocytochemical examination and Western blotting. Effects of S1PR1- specific small interfering RNA (siRNA) and that of FTY720-P (a functional S1PR1-antagonist) on MO-LAS cell chemotactic migration towards sphingosine-1-phosphate (S1P) or 10% fetal bovine serum (FBS) were assessed by Transwell migration assay; wound healing assays for random cell migration were performed using a live cell analyzer. Immunostaining revealed high expression of S1PR1 on the MO-LAS cell membrane. Transwell and wound-healing assays showed that S1P enhanced chemotactic and random migration of MO-LAS cells, respectively. Inhibition of S1PR1 expression with siRNA significantly attenuated chemotaxis of cells towards S1P and 10% FBS. Further, FTY720-P strongly induced the internalization and degradation of S1PR1 even in the presence of serum containing S1P. It attenuated chemotactic cell migration of MO-LAS towards both S1P and serum, as well as the random motility of cells at nanomolar concentrations. These results suggest that the S1P/S1PR1 axis may be a potential therapeutic target for inhibition of angiosarcoma metastasis by controlling its cell motility

赤芽球癆を合併したT-cell large granular lymphocyte leukemia の一例

T-cell large granular lymphocyte leukemia は長期(6か月以上)にわたる末梢血中の著明な大顆粒リンパ球(large granular lymphocyte;以下,LGL)のモノクローナルな増加によって特徴づけられる疾患で,しばしば赤芽球癆を伴うことが知られている.今回,我々はHCV陽性肝硬変患者に赤芽球癆を合併したT-LGLの1例を経験した.末梢血および骨髄塗抹標本では細胞質内に微細なアズール顆粒を有し,核異型を示すリンパ球の増加がみられ,末梢血および骨髄のフローサイトメトリーおよび骨髄吸引クロット標本の免疫組織化学で,CD3,CD8,CD57陽性リンパ球の増加が確認された.骨髄細胞のPCRではTCRβの再構成を認めず,TCRγおよびTCRδの再構成がみられた.またプレドニゾロン治療にてCD57陽性リンパ球の減少および赤芽球造血の回復が確認されたことから,赤芽球癆を合併したγδT-LGLと診断した.最近,T-LGLにはSTAT3あるいはSTAT5bのSHドメインの遺伝子変異が高頻度にみられることが報告されているが,本症例においては,これらの遺伝子変異は確認できなかった.T-cell large granular lymphocytic leukemia (T-LGL) is characterized by marked increase of monoclonal large granular lymphocytes (LGL) in the peripheral blood over the long term (6 months or more). It has been reported about 20% cases of T-LGL cases are associated with pure red cell aplasia (PRCA). Here, we describe a case of T-LGL associated with PRCA. This case was characterized by increase in the number of CD3+,CD8+,CD57+, and granzyme B-positive lymphocytes with fine azurophilic cytoplasmic granules and nuclear atypia in peripheral blood and bone marrow. The patient was diagnosed havingγδT-LGL because T-cell receptor (TCR)γ and TCRδ gene but not TCRβ gene rearrangement was detected by the PCR of the bone marrow cells. Prednisolone administration decreased in number of the LGL cells, accompanying recover of erythropoiesis. Although somatic mutations in the Src homology 2 domain of STAT3 or STAT5b gene are reported in 70% percent of the T-LGL with PRCA, such STAT mutations could not be detected in this case