Cytologic findings of epithelioid angiosarcoma of the thyroid. A case report

BACKGROUND: Angiosarcoma of the thyroid is a rare and aggressive tumor and occurs mainly in patients from central Europe, especially the alpine region. The fine needle aspiration findings of a keratin-positive epithelioid angiosarcoma of the thyroid occurring in a nonmountainous area in South America is described. CASE: A 65-year-old male from S?o Paulo, Brazil, presented with a mass in the anterior part of the neck with progressive enlargement for three months. The cytologic findings on the fine needle aspirate were a cellular smear composed of single cells and small clusters of neoplastic cells, oval and round. Cell borders were indistinct, and the cytoplasm was vacuolated. The nuclei were eccentrically located, with irregular nuclear membranes; single, prominent nucleoli; and a coarse chromatin pattern. Features suggestive of intracytoplasmic lumens were identified. Open surgical biopsy demonstrated a tumor infiltrating the thyroid gland and composed of large, round, atypical epithelioid cells lining vascular spaces. These neoplastic cells were immunoreactive for AE1:AE3, CK7, vimentin, CD31 and factor VIII. CONCLUSION: Epithelioid angiosarcoma should be considered in the differential diagnosis of epithelioid neoplasms of the thyroid. An immunohistochemical panel should include vascular markers even in the presence of immunoreactivity for epithelial markers.     

Renal cell carcinoma metastatic to follicular adenoma of the thyroid gland. A case report

BACKGROUND: Renal cell carcinoma is an unpredictable tumor that can recur many years after the original diagnosis and metastasize to uncommon sites, including the thyroid gland. Differential diagnosis from primary thyroid tumor is often difficult both clinically and pathologically. We report a case of metastatic renal cell carcinoma in follicular adenoma of the thyroid gland. CASE: A 48-year-old woman presented with a 3-cm-diameter, palpable mass in the left lobe of the thyroid gland. The patient's history included removal of a left renal mass, which was conventional renal cell carcinoma. Fine needle aspiration cytology smears contained a few small clusters of polygonal cells with abundant, clear cytoplasm and irregular, hyperchromatic nuclei as well as bland-looking thyroid follicle cells and stromal cells. A papillary or follicular growth pattern was not detected. A cell block made from the aspirated sample was composed mainly of clear cells. By immunohistochemical stains, the clear cells were completely negative for TTF-1, thyroglobulin, calcitonin and inhibin while equivocally staining for cytokeratin, CD10 and galectin-3. The histologic diagnosis was renal cell carcinoma metastatic to follicular adenoma of the thyroid gland. CONCLUSION: Renal cell carcinoma metastatic to the thyroid may masquerade as a primary thyroid neoplasm. A history of prior nephrectomy, the presence of unremarkable thyroid follicle cells, the absence of a papillary or follicular growth pattern and immunohistochemical study can help differentiating metastatic renal cell carcinoma from a primary thyroid lesion with clear cell change.     

Diagnosis of gastric glomus tumor by endoscopic ultrasound-guided fine needle aspiration biopsy. A case report with cytologic,histologic and immunohistochemical studies

BACKGROUND: The majority of glomus tumor are small, benign neoplasms that arise from modified smooth muscle cells. They usually occur in the dermis or subcutis of the extremities. However, rare cases have been reported in the visceral locations, most often in the stomach. CASE: A 32-year-old woman presented with episodes of right upper quadrant pain. She was found to have a gastric tumor that was biopsied at another hospital, where the diagnosis of gastrointestinal stromal tumor (GIST) was made. Endoscopic ultrasound (EUS) performed at our institution revealed a gastric submucosal tumor that was then biopsied by fine needle aspiration (FNA). Cytology revealed cohesive clusters of uniform, round, small cells with ill-defined cytoplasmic borders and scanty, amphophilic cytoplasm. Nuclei were round, with smooth nuclear membranes and evenly distributed, dusty chromatin. Intermingled with those epithelioid cells were small, short, spindled, normal endothelial cells. Immunohistochemical studies performed on cell block showed that the tumor cells were negative for CD34, CD117, chromogranin, synaptophysin, desmin and AE1/AE3 and were strongly positive for SMA, HHF-35 and collagen type IV. Glomus tumor was diagnosed and later confirmed by histology. CONCLUSION: EUS-guided FNA biopsy is efficient and permits adequate sampling for accurate diagnosis of gastric glomus tumor. Although rare, glomus tumor should be in the differential diagnosis among other gastric lesions, such as well-differentiated adenocarcinoma, epithelioid GIST and carcinoid tumor.     

Silencing of CD44 Gene Expression in Human 143-B Osteosarcoma Cells Promotes Metastasis of Intratibial Tumors in SCID Mice

Osteosarcoma (OS) is the most frequent primary malignant bone cancer in children and adolescents with a high propensity for lung metastasis. Therefore, it is of great importance to identify molecular markers leading to increased metastatic potential in order to devise more effective therapeutic strategies that suppress metastasis, the major cause of death in OS. CD44, the principal receptor for the extracellular matrix component hyaluronan (HA), is frequently found overexpressed in tumor cells and has been implicated in metastatic spread in various cancer types. Here, we investigated the effects of stable shRNA-mediated silencing of CD44 gene products on in vitro and in vivo metastatic properties of the highly metastatic human 143-B OS cell line. In vitro, CD44 knockdown resulted in a 73% decrease in the adhesion to HA, a 57% decrease in the migration rate in a trans-filter migration assay, and a 28% decrease in the cells'' capacity for anchorage-independent growth in soft agar compared to the control cells, implicating that CD44 expression contributes to the metastatic activity of 143-B cells. However, making use of an orthotopic xenograft OS mouse model, we demonstrated that reduced CD44 expression facilitated primary tumor growth and formation of pulmonary metastases. The enhanced malignant phenotype was associated with decreased adhesion to HA and reduced expression of the tumor suppressor merlin in vivo. In conclusion, our study identified CD44 as a metastasis suppressor in this particular experimental OS model.     

Malignant epithelioid gastrointestinal stromal tumors: report of a case with cytologic and immunohistochemical studies

BACKGROUND: Gastrointestinal stromal tumors (GISTs) may exhibit a fusiform, epithelioid or mixed pattern of growth. Only rare articles report the cytologic and immunohistochemical features of malignant epithelioid tumors. CASE: A 57-year-old woman presented with a tumor mass in the small intestine omentum measuring 8 x 7 cm; it was surgically removed. Five years later 2 mesenteric relapses were studied by fine needle aspiration biopsy and later surgically excised. Cytologically the smears contained small clusters of epithelioid and plasmacytoid cells with round nuclei. The presence of nucleoli and occasional nuclear grooves were prominent. Focally the background was myxoid. Histologically the tumor showed an epithelioid pattern with moderate pleomorphism and mitoses in 6 of 50 high-power fields. Immunohistochemical study showed positivity for c-kit (CD117), vimentin, smooth muscle actin and caldesmon, and focally for desmin and cytokeratin. CONCLUSION: This case illustrates the difficulty in making a reliable diagnosis of the epithelioid variant of GIST by cytology alone. The immunohistochemical panel (apart from c-kit) should include smooth muscle markers and cytokeratins because they are more likely to be reactive. A complete cytoimmunohistochemical evaluation is mandatory to make an accurate diagnosis.     

Cytopathologic features of pituitary carcinoma with cervical vertebral bone metastasis: a case report

BACKGROUND: Pituitary carcinomas are extremely rare tumors of the adenohypophysis. The presence of craniospinal and/or systemic extracranial metastases is the only reliable criterion for the diagnosis of pituitary carcinoma. To date, only 2 cases have been reported correctly by fine needle aspiration biopsy (FNAB). We present an additional case of pituitary carcinoma with FNAB features. CASE: A 60-year-old woman presented with clinical features of Cushing's disease and a pituitary tumor. She underwent transsphenoidal resection of the tumor. The initial diagnosis was an adrenocorticotrophic hormone (ACTH)-producing invasive pituitary adenoma. The patient presented again with neck pain 6 years after the operation. Magnetic resonance imaging revealed metastatic tumor masses at the level of C5-C6 of the cervical vertebrae. Intraoperative fine needle aspiration and incomplete excision of metastatic tumors were performed. Cytologically, tumor cells were composed of a combination of loose groups and single cells. Neoplastic cells had a relatively monotonous appearance and displayed characteristic neuroendocrine tumor features. Immunocytochemistry from cell block sections revealed AE1/ AE3, synaptophysin chromogranin A and ACTH positivity in the tumor cells. CONCLUSION: Pituitary carcinoma with extracranial systemic metastases demonstrates typical neuroendocrine features on fine needle aspiration. In the differential diagnosis, metastatic neuroendocrine carcinomas should be kept in mind. In the absence of sufficient clinical data, these 2 entities cannot be distinguished correctly through the cytologic features.     

HER2阳性乳腺癌中CD44v6的表达与曲妥珠单抗耐药的关系

目的:探讨曲妥珠单抗在治疗HER2阳性的转移性乳腺癌时,产生耐药性与CD44v6表达的相关性。方法:共66例HER2阳性转移性乳腺癌患者入组。接受曲妥珠单抗治疗的患者37例,其中18例获得了治疗前和治疗后转移性癌组织。采用免疫组化S-P法对治疗前、治疗后的不同乳腺组织进行CD44v6表达的研究。结果:CD44v6在经曲妥珠单抗治疗产生耐药的活检组织中阳性表达程度明显高于治疗前。结论:CD44v6的表达与曲妥珠单抗耐药相关。     

Hyaluronate receptor CD44 is expressed by astrocytes in the adult chicken and in astrocyte cell precursors in early development of the chick spinal cord.

The role of the hyaluronate receptor, CD44, is well known in adult mammal astrocytes where it modulates neuron-glia interactions. However, no data exist regarding its expression in other vertebrates during their development. In order to detect the expression of CD44 in the chicken and its possible involvement in glial precursor migratory patterns during spinal cord development, a monoclonal antibody (MoAb) against the mammalian standard isoform, CD44-H, was used in immunohistochemical and immunoblot assays. With these methods, CD44 hyaluronate receptors were found on mature astrocyte membranes of adult chicken spinal cord. Astrocytes were identified using a MoAb against GFAP. During development, small clusters of CD44 labelled cells were seen lining the central canal starting from embryonic stage E10. These labelled cells were dispersed in the dorsal, lateral and ventral funiculi of the spinal cord in the subsequent stages. After stage E15, the CD44 labelled cells were identified as astrocytes because of their GFAP immunoreactivity. We conclude that CD44 receptors on immature astrocyte precursors should be considered as early astrocyte markers which have a possible role during cell migratory dispersal.     

Expression of CD44 Splice Variants During Lymphocyte Activation and Tumor Progression

Recently, splice variants of CD44 have been described that confer metastatic potential to non-metastasizing rat pancreatic carcinoma and sarcoma cell lines. Using antibodies against variant CD44 (CD44v) sequences, we have examined the expression of variant CD44 glycoproteins on human lymphoid cells and tissues and in colorectal neoplasia. Lymphohematopoietic cells express low levels of CD44v glycoproteins. During the process of lymphocyte activation in vitro and in vivo, expression of CD44v glycoproteins is transiently upregulated. The reaction pattern of various antibodies indicates that these CD44 variants contain the domain encoded by exon v6, which is part of the variant that confers metastatic capability. In human colorectal neoplasia we observed overexpression of CD44 splice variants in all invasive carcinomas. Already at early stages of colorectal tumor progression exon v5 epitopes were overexpressed. Tumor progression was strongly related to expression of CD44 isoforms containing exon v6 encoded domains. The findings establish CD44 variants as tumor progression markers in colorectal cancer.     

Expression of CD44 Splice Variants During Lymphocyte Activation and Tumor Progression

Recently, splice variants of CD44 have been described that confer metastatic potential to non-metastasizing rat pancreatic carcinoma and sarcoma cell lines. Using antibodies against variant CD44 (CD44v) sequences, we have examined the expression of variant CD44 glycoproteins on human lymphoid cells and tissues and in colorectal neoplasia. Lymphohematopoietic cells express low levels of CD44v glycoproteins. During the process of lymphocyte activation in vitro and in vivo, expression of CD44v glycoproteins is transiently upregulated. The reaction pattern of various antibodies indicates that these CD44 variants contain the domain encoded by exon v6, which is part of the variant that confers metastatic capability. In human colorectal neoplasia we observed overexpression of CD44 splice variants in all invasive carcinomas. Already at early stages of colorectal tumor progression exon v5 epitopes were overexpressed. Tumor progression was strongly related to expression of CD44 isoforms containing exon v6 encoded domains. The findings establish CD44 variants as tumor progression markers in colorectal cancer.     

胃癌CD44v6 mRNA及其蛋白表达与临床病理特征的关系

目的探讨细胞粘附分子CD44v6 mRNA及其蛋白表达与胃癌临床病理学行为和患者预后的关系. 方法应用高敏感性催化信号放大系统(catalyzed signal amplification,CSA)原位杂交和免疫组化技术,对17例早期胃癌、21例中期胃癌和57例晚期胃癌组织进行CD44v6 mRNA及其蛋白检测,并结合肿瘤的病理学行为和临床随访资料进行分析.结果在胃癌中,CD44v6 mRNA及其蛋白的表达阳性率分别为85.3%和82.1%.CD44v6 mRNA及其蛋白表达阳性率在晚期胃癌明显高于早、中期胃癌(P<0.05).CD44v6 mRNA表达与蛋白表达水平具有一致性,均与胃癌浆膜浸润,淋巴结转移和患者预后呈正相关(P<0.05).结论 CD44v6 mRNA及其蛋白异常表达与胃癌的临床病理生物学行为密切相关,特别是与胃癌细胞的转移潜能和胃癌患者的不良预后密切相关.CD44v6蛋白水平的表达可以间接反映其mRNA转录水平,并可作为预测胃癌转移潜能和患者预后的一个新的生物学指标.     

Identification of glycoprotein markers for pancreatic cancer CD24+CD44+ stem-like cells using nano-LC-MS/MS and tissue microarray

Pancreatic adenocarcinoma is characterized by late diagnosis due to lack of early symptoms, extensive metastasis, and high resistance to chemo/radiation therapy. Recently, a subpopulation of cells within pancreatic cancers, termed cancer stem cells (CSCs), has been characterized and postulated to be the drivers for pancreatic cancer and responsible for metastatic spread. Further studies on pancreatic CSCs are therefore of particular importance to identify novel diagnosis markers and therapeutic targets for this dismal disease. Herein, the malignant phenotype of pancreatic cancer stem-like CD24+CD44+ cells was isolated from a human pancreatic carcinoma cell line (PANC-1) and demonstrated 4-fold increased invasion ability compared to CD24-CD44+ cells. Using lectin microarray and nano LC-MS/MS, we identified a differentially expressed set of glycoproteins between these two subpopulations. Lectin microarray analysis revealed that fucose- and galactose-specific lectins, UEA-1 and DBA, respectively, exhibit distinctly strong binding to CD24+CD44+ cells. The glycoproteins extracted by multilectin affinity chromatography were consequently analyzed by LC-MS/MS. Seventeen differentially expressed glycoproteins were identified, including up-regulated Cytokeratin 8/CK8, Integrin β1/CD29, ICAM1/CD54, and Ribophorin 2/RPN2 and down-regulated Aminopeptidase N/CD13. Immunohistochemical analysis of tissue microarrays showed that CD24 was significantly associated with late-stage pancreatic adenocarcinomas, and RPN2 was exclusively coexpressed with CD24 in a small population of CD24-positive cells. However, CD13 expression was dramatically decreased along with tumor progression, preferentially present on the apical membrane of ductal cells and vessels in early stage tumors. Our findings suggest that these glycoproteins may provide potential therapeutic targets and promising prognostic markers for pancreatic cancer.     

Adipose-derived stem cells and cancer cells fuse to generate cancer stem cell-like cells with increased tumorigenicity

Adipose-derived stem cells (ADSCs) are a type of mesenchymal stem cells isolated from adipose tissue and have the ability to differentiate into adipogenic, osteogenic, and chondrogenic lineages. Despite their great therapeutic potentials, previous studies showed that ADSCs could enhance the proliferation and metastatic potential of breast cancer cells (BCCs). In this study, we found that ADSCs fused with BCCs spontaneously, while breast cancer stem cell (CSC) markers CD44⁺CD24^-/lowEpCAM⁺ were enriched in this fusion population. We further assessed the fusion hybrid by multicolor DNA FISH and mouse xenograft assays. Only single nucleus was observed in the fusion hybrid, confirming that it was a synkaryon. In vivo mouse xenograft assay indicated that the tumorigenic potential of the fusion hybrid was significantly higher than that of the parent tumorigenic triple-negative BCC line MDA-MB-231. We had compared the fusion efficiency between two BCC lines, the CD44-rich MDA-MB-231 and the CD44-poor MCF-7, with ADSCs. Interestingly, we found that the fusion efficiency was much higher between MDA-MB-231 and ADSCs, suggesting that a potential mechanism of cell fusion may lie in the dissimilarity between these two cell lines. The cell fusion efficiency was hampered by knocking down the CD44. Altogether, our findings suggest that CD44-mediated cell fusion could be a potential mechanism for generating CSCs.     

The microRNA miR-34a inhibits prostate cancer stem cells and metastasis by directly repressing CD44

Cancer stem cells (CSCs), or tumor-initiating cells, are involved in tumor progression and metastasis. MicroRNAs (miRNAs) regulate both normal stem cells and CSCs, and dysregulation of miRNAs has been implicated in tumorigenesis. CSCs in many tumors--including cancers of the breast, pancreas, head and neck, colon, small intestine, liver, stomach, bladder and ovary--have been identified using the adhesion molecule CD44, either individually or in combination with other marker(s). Prostate CSCs with enhanced clonogenic and tumor-initiating and metastatic capacities are enriched in the CD44(+) cell population, but whether miRNAs regulate CD44(+) prostate cancer cells and prostate cancer metastasis remains unclear. Here we show, through expression analysis, that miR-34a, a p53 target, was underexpressed in CD44(+) prostate cancer cells purified from xenograft and primary tumors. Enforced expression of miR-34a in bulk or purified CD44(+) prostate cancer cells inhibited clonogenic expansion, tumor regeneration, and metastasis. In contrast, expression of miR-34a antagomirs in CD44(-) prostate cancer cells promoted tumor development and metastasis. Systemically delivered miR-34a inhibited prostate cancer metastasis and extended survival of tumor-bearing mice. We identified and validated CD44 as a direct and functional target of miR-34a and found that CD44 knockdown phenocopied miR-34a overexpression in inhibiting prostate cancer regeneration and metastasis. Our study shows that miR-34a is a key negative regulator of CD44(+) prostate cancer cells and establishes a strong rationale for developing miR-34a as a novel therapeutic agent against prostate CSCs.     

A quantitative proteomics analysis of MCF7 breast cancer stem and progenitor cell populations

Accumulating evidence has demonstrated that breast cancers are initiated and develop from a small population of stem‐like cells termed cancer stem cells (CSCs). These cells are hypothesized to mediate tumor metastasis and contribute to therapeutic resistance. However, the molecular regulatory networks responsible for maintaining CSCs in an undifferentiated state have yet to be elucidated. In this study, we used CSC markers to isolate pure breast CSCs fractions (ALDH+ and CD44+CD24‐ cell populations) and the mature luminal cells (CD49f‐EpCAM+) from the MCF7 cell line. Proteomic analysis was performed on these samples and a total of 3304 proteins were identified. A label‐free quantitative method was applied to analyze differentially expressed proteins. Using the criteria of greater than twofold changes and p value <0.05, 305, 322 and 98 proteins were identified as significantly different in three pairwise comparisons of ALDH+ versus CD44+CD24‐, ALDH+ versus CD49f‐EpCAM+ and CD44+CD24‐ versus CD49f‐EpCAM+, respectively. Pathway analysis of differentially expressed proteins by Ingenuity Pathway Analysis (IPA) revealed potential molecular regulatory networks that may regulate CSCs. Selected differential proteins were validated by Western blot assay and immunohistochemical staining. The use of proteomics analysis may increase our understanding of the underlying molecular mechanisms of breast CSCs. This may be of importance in the future development of anti‐CSC therapeutics.     

Rb Suppresses Collective Invasion,Circulation and Metastasis of Breast Cancer Cells in CD44-Dependent Manner

Basal-like breast carcinomas (BLCs) present with extratumoral lymphovascular invasion, are highly metastatic, presumably through a hematogenous route, have augmented expression of CD44 oncoprotein and relatively low levels of retinoblastoma (Rb) tumor suppressor. However, the causal relation among these features is not clear. Here, we show that Rb acts as a key suppressor of multiple stages of metastatic progression. Firstly, Rb suppresses collective cell migration (CCM) and CD44-dependent formation of F-actin positive protrusions in vitro and cell-cluster based lymphovascular invasion in vivo. Secondly, Rb inhibits the release of single cancer cells and cell clusters into the hematogenous circulation and subsequent metastatic growth in lungs. Finally, CD44 expression is required for collective motility and all subsequent stages of metastatic progression initiated by loss of Rb function. Altogether, our results suggest that Rb/CD44 pathway is a crucial regulator of CCM and metastatic progression of BLCs and a promising target for anti-BLCs therapy.     

Macrophage-rich reaction in lymph nodes as a mimic of metastatic renal cell carcinoma on fine needle aspiration. A case report

BACKGROUND: Renal cell carcinomas have a high metastatic potential. Many of them are occult at initial presentation and mimic a primary neoplasm of the metastatic site. However, not all lymph node enlargements in a patient with a history of renal cell carcinoma are due to metastasis. Foamy macrophages can mimic metastatic renal cell carcinoma cells. CASE: A 60-year-old male with a known diagnosis of renal cell carcinoma of clear cell type developed enlarged neck nodes 44 months after the diagnosis. These were aspirated to yield cystic fluid that, on smears, showed numerous clear cells with low nuclear grade. Immunohistochemical stains revealed these cells to be foamy macrophages (CD68 immunoreactive) and not metastatic renal cell carcinoma, as had been suspected on initial examination of Diff-Quik and Papanicolaou-stained smears. CONCLUSION: Immunohistochemistry is a valuable adjunct in avoiding a false diagnosis of metastatic carcinoma in macrophage-rich nodal reactions in patients with a history of renal cell carcinoma.     

Fine needle aspiration cytology of hepatic metastasis from a meningeal hemangiopericytoma. A case report

BACKGROUND: Hemangiopericytomas (HPCs) are rare spindle cell tumors, constituting 2.5% of soft tissue neoplasms. Few reports have addressed the fine needle aspiration (FNA) cytology of HPC. CASE: We describe the FNA biopsy (FNAB) findings in a 44-year-old patient with a previously resected meningeal hemangiopericytoma. The patient underwent ultrasound-guided FNAB of a 16.0-cm, radiographically heterogeneous density in the liver. The FNA smear showed crowded, ovoid to spindle-shaped cells with poorly defined, scant cytoplasm. The neoplastic cells were positive for CD34 and negative for CD31, factor VIII, glial fibrillary acid protein and cytokeratin AE1/AE3, supporting a diagnosis of HPC and compatible with metastasis from the patient's cerebral tumor. CONCLUSION: This case documents the role of FNA cytology in confirming HPC.