Solitary Fibrous Tumor of Head and Neck Region: A Series of Three Cases at an Uncommon Location With a Review of the Literature

Solitary fibrous tumors (SFTs) uncommonly involve the head and neck region. Head and neck SFTs (HNSFTs) exhibit diverse histological features and can mimic several neoplasms with different treatment and behavior. Herein, we report the clinicopathological features of three cases of HNSFT. Case 1 was a 29-year-old female who presented with a nasal cavity mass measuring 3.5 cm. The patient underwent surgical excision. Microscopic examination revealed classic histological and immunohistochemical (IHC) features of SFT. Unusual histological features included epithelioid morphology, clear cells, and edematous change. She developed local recurrence after 11 months, which was also treated with surgery. Case 2 was a 55-year-old male who developed a 1-cm mass at the buccal mucosa. Surgical excision of the tumor was performed. The tumor was completely circumscribed microscopically. Characteristic histological and IHC features of SFT were identified. Unusual histological features observed were an adenomatous pattern, clear cells, and myxoid change. The patient was alive and disease-free at the 12-month follow-up. Case 3 was a 59-year-old female presenting with a medial canthus mass measuring 1.4 cm. The patient underwent surgical excision. Histological and IHC features observed were diagnostic for SFT. Unusual histological features identified were wavy nuclei and multinucleated stromal giant cells. The patient was alive and disease-free at the 124-month follow-up. Diagnosis of SFT can be challenging in unusual locations like the head and neck region. In addition, the histological spectrum of HNSFT is diverse. Therefore, knowledge about unusual histological features and classic IHC expression is essential for establishing correct diagnosis. Long-term follow-up is recommended because of the risk of recurrence in HNSFT.

Fetal vascular malperfusion score is linked with developing preeclampsia in women with gestational diabetes mellitus: a retrospective cohort study

OBJECTIVE

Fetal vascular malperfusion is associated with poor perinatal outcomes in women with preeclampsia and gestational diabetes mellitus. The aim of this study was to determine the association between fetal vascular malperfusion score and syncytiotrophoblast basement membrane thickness and clinicopathological variables, such as developing preeclampsia in women with gestational diabetes mellitus.

METHODS

This retrospective cohort study included 65 pregnant participants (34 with gestational diabetes mellitus and 31 controls) between January 2019 and January 2022. Gestational diabetes mellitus was diagnosed as ≥2 of 4 elevated values on a 3-h, 100-g oral glucose tolerance test. The fetal vascular malperfusion score was evaluated by endothelial CD34 positivity in the villous stroma of the placenta. The association between fetal vascular malperfusion score and syncytiotrophoblast basement membrane thickness with clinicopathological variables in women with gestational diabetes mellitus was evaluated.

RESULTS

It was revealed that the gestational diabetes mellitus group had greater fetal vascular malperfusion scores than the control group (gestational diabetes mellitus group fetal vascular malperfusion score: 34.2±9.1 and control group fetal vascular malperfusion score: 26.5±8.7, respectively, p=0.0009). Syncytiotrophoblast basement membrane thickness was correlated with the development of preeclampsia, trophoblast proliferation, and fetal vascular malperfusions (0.3952, p=0.0129; 0.3487, p=0.0211; and 0.4331, p=0.0082, respectively). On the contrary, fetal vascular malperfusions were correlated with the development of preeclampsia, villous edema, and trophoblast proliferation (0.3154, p=0.0343; 0.2922, p=0.4123; and 0.3142, p=0.0355, respectively).

CONCLUSION

The gestational diabetes mellitus group displayed significantly higher fetal vascular malperfusion scores and thickening of the syncytiotrophoblast basement membrane than the control group. There is a correlation between developing preeclampsia and the fetal vascular malperfusion scores and the syncytiotrophoblast basement membrane thickness.

Utility of CD34 in Assessing Microvessel Density and Its Correlation With Clinicopathological Parameters in Colorectal Carcinoma Patients

Currently, the most commonly practiced method of reporting cases of colorectal carcinoma is done according to guidelines provided by the College of American Pathologists (8th edition) and the Royal College of Pathologists (UK). These guidelines include various histopathological parameters like tumor site, extent, histologic type, grade, margins, tumor budding, lymphovascular invasion, and perineural invasion. However, in the present guidelines, the immunohistochemistry-based marker of mean vessel density (MVD) has not been addressed as an important parameter. The present study gives an overview of the importance of MVD. MVD was statistically significant when correlated with tumor size, lymph node metastasis, grade, and vascular invasion. However, no statistical significance was observed when compared with age, perineural invasion, and stage of the tumor.

Malignant Extrapleural Solitary Fibrous Tumor

Solitary fibrous tumors (SFTs) are rare spindle cell neoplasms of mesenchymal origin that are most commonly found in the pleura, although they have also been documented in extrapleural locations. SFTs affect males and females in equal distribution, and they typically occur between the fourth and seventh decades of life. Since SFTs are usually benign and asymptomatic, the majority of them are discovered incidentally on computed tomography (CT) or magnetic resonance imaging (MRI) imaging, unless they grow to a size that causes mass effect symptoms on other organs. Nonetheless, imaging is not sufficient to diagnose an SFT, and therefore, biopsy is recommended for further analysis. Advances in immunohistochemistry and molecular diagnostics have identified CD34 and NAB2-STAT6, respectively, as the most consistent markers for SFTs. The risk of SFT metastasis can be determined through the use of a four-variable risk-stratification model developed by Demicco et al., which is based upon the risk factors of patient age, tumor size, mitotic count per 10 high-power fields, and the degree of tumor necrosis. The management of SFTs involves a wide surgical resection of the tumor while preserving surrounding organs and structures. Post-operative surveillance involves imaging the primary tumor site for up to five years due to the risk of local recurrence. At this time, neither radiation therapy nor chemotherapy after resection have yet to show benefit, and therefore, they are not currently recommended. This case report discusses the management of a 68-year-old woman who was diagnosed with a malignant extrapleural SFT in her right medial upper thigh.

Correlations of Disc Tissue Pathological Changes With Pfirrmann Grade in Patients With Disc Herniation Treated With Microdiscectomy

BACKGROUND

To reveal whether pathological disc changes (vascularization, inflammation, disc aging and senescence as assessed with immunohistopathological CD34, CD68, brachyury and P53 staining densities respectively) are associated with the extent of disease (Pfirrmann grade) and lumbar radicular pain in patients with lumbar disc herniation. We selectively included a homogenous group of 32 patients (16 males and 16 females) with single-level sequestered discs who had disease stages between Pfirrmann grades I to IV and excluded patients with the complete collapse of the disc space to determine histopathological correlations of the disease more precisely.

MATERIALS AND METHODS

Pathological assessments were performed on surgically excised disc specimens stored in a -80°C refrigerator. Preoperative and postoperative pain intensities were determined with visual analog scales (VASs). Pfirrmann disc degeneration grades were determined on routine T2-weighted magnetic resonance imaging (MRI).

RESULTS

Stainings were especially observed with CD34 and CD68, which positively correlated with each other and Pfirrmann grading but not with VAS scores or patients' age. Weak nuclear staining with brachyury was observed in 50% of patients and did not correlate with disease features. Focal weak staining with P53 was only seen in the disc specimen of two patients.

CONCLUSIONS

In the pathogenesis of disc disease, inflammation may trigger angiogenesis. The subsequent aberrant increase of oxygen perfusion in the disc cartilage may cause further damage, as the disc tissue is adapted to hypoxia. This vicious cycle of inflammation and angiogenesis may be a future innovative therapeutic target for chronic degenerative disc disease.

DOG1-Positive Extragastrointestinal Stromal Tumor Presenting As Large Abdomino-Pelvic Mass: A Case Report

Gastrointestinal stromal tumors (GIST) are mesenchymal tumors commonly arising from the GI tract. Only a small number of GIST originating outside the GI tract have been reported in the literature. They are termed extraintestinal GIST (E-GIST), with histological features similar to GIST. These commonly arise from the omentum, mesentery, or abdominal wall. Microscopic examination shows spindle or epitheloid morphology with immunohistochemistry (IHC) positivity for the cluster of differentiation 117, 34 (CD117, CD34), or discovered on GIST-1 (DOG1). This case series describes the presentation of two cases of E-GIST as an abdominopelvic mass with DOG1 positivity and CD117 negativity on IHC. Patient in the first case presented with a giant abdominopelvic mass, clinically arising from the pelvis with a misdiagnosis of midline desmoid tumor. It was completely excised with a histological surprise of E-GIST with DOG1 positivity on IHC. The second case presented a swelling in the groin region, separate from the testis but arising from the anterior abdominal wall, with histological features of E-GIST with DOG1 positivity. The cases reported here show further evidence regarding the existence of a distinct subset of GISTs characterized by extraintestinal localization, with negative immunohistochemical expression of receptor tyrosine kinases (KIT) and positive DOG1 expression, which appears to be rare and makes DOG1 an emerging marker for GIST.

Two cases of congenital dermatomyofibroma

We present two infants with histologically confirmed congenital dermatomyofibromas. Congenital cases are rare with only one prior case reporting presence since birth. Given the benign nature of the lesions and propensity of dermatomyofibromas to resolve without intervention in young male patients, no additional treatments were pursued.

Primary Mammary Angiosarcoma: Literature Review

Angiosarcomas of the breast are extremely rare, highly aggressive tumors of vascular origin comprising 0.04% of all malignant neoplasms of the breast. They can be classified into primary mammary angiosarcomas and cutaneous (secondary) angiosarcomas. Primary angiosarcomas, owing to their unusual clinical presentation, are diagnosed late. In addition, the available literature to date lacks sufficient evidence to establish standard treatment guidelines for this group of tumors, thereby resulting in poor prognosis. In medical database, most available papers concern secondary angiosarcomas, with only a few case reports of primary angiosarcomas. The aim of this paper is to review what is known hitherto about the presentation, diagnostic tools, and therapeutic modalities for primary mammary angiosarcomas.

The relationship between HER2 overexpression and angiogenesis in gastric cancer

In gastric cancer, HER2 protein overexpression is considered to be conducive to the higher proliferation activity of the tumor cells. Tumor formation is associated with angiogenesis in order to secure an abundant supply of oxygen and glucose to cancer cells. The aim of the study was to assess if HER2 overexpression is related to higher microvessel density (MVD) in the tumor stroma.The archival samples of primary tumor from 144 consecutive patients that underwent gastric resection for cancer between August 1, 2006 and December 31, 2013 in the Department of Oncological Surgery of Medical University of Gdańsk were analyzed. CD34 was used as a marker of MVD in the tumor stroma. Both CD34 and HER2 protein expressions were tested by immunohistochemistry.The assays were unsuccessful to estimate HER2 in 10 cases and CD34 in 14 cases due to technical reasons. The results were obtained for 128 patients. HER2 0 and HER2 1+ were considered negative, while HER2+ and HER2 3+ were recognized as positive. Mean MVD (mean number of vessels in the visual field) was 32.4 (median 29.5). Microvessel density was insignificantly higher in HER2 positive tumors. The slight difference was also seen between IHC 2+ and 3+ groups. The differences did not reach the level of statistical significance.Statistical analysis performed in our study did not reveal the significant relationship between HER2 overexpression on the tumor cells and MVD in the tumor stroma.

Endothelial follicle-stimulating hormone receptor expression in invasive breast cancer and vascular remodeling at tumor periphery

BACKGROUND

Follicle-stimulating hormone receptor (FSHR) is expressed on the endothelial surface of blood vessels associated with solid tumor periphery, where angiogenesis is known to occur. The correlation between FSHR expression and formation of new peritumoral vessels has not been previously investigated.

METHODS

We used immunohistochemical techniques involving specific antibodies to detect FSHR and the endothelial markers (CD34, VEGFR2, and D2-40) in tissue samples from 83 patients with lymph node-negative, invasive breast cancer representing four main clinical treatment groups: HR+/HER2-, HR+/HER2+, HR-/HER2+ and triple-negative.

RESULTS

The FSHR+ vessels were exclusively located at breast cancer periphery, in a layer that extended 2 mm into and 5 mm outside of the tumor. The percentage of blood vessels expressing FSHR reached a maximum of 100% at the demarcation line between the tumor and the normal tissue. Common among FSHR+ vessels, regardless of breast cancer type, were the high densities of arterioles and venules (6.4 ± 1.4 and 13.9 ± 2.1 vessels/mm(2), respectively). These values were 3-fold higher that those noticed for CD34+ arterioles and venules associated with normal breast tissue located at a distance greater than 10 mm outside the tumors. The average density of FSHR+ and CD34+ blood vessels as well as of D2-40+ lymphatic vessels did not differ significantly among breast cancer subgroups. FSHR+ vessels did not express VEGFR2. The endothelial FSHR expression correlated significantly with the peritumoral CD34+ vessels' density (p < 0.001) and tumor size (p = 0.01).

CONCLUSION

Endothelial FSHR expression in breast cancer is associated with vascular remodeling at tumor periphery.

DPP-4 inhibitor and alpha-glucosidase inhibitor equally improve endothelial function in patients with type 2 diabetes: EDGE study

BACKGROUND

Alpha glucosidase inhibitor (GI) attenuates postprandial hyperglycemia (PPH) and reduces the risk of cardiovascular events in patients with impaired glucose tolerance or type 2 diabetes. Dipeptidyl peptidase 4 (DPP-4) inhibitors also attenuate PPH. PPH is one of the factors leading to endothelial dysfunction which is an early event in the pathogenesis of atherosclerosis. Furthermore, DPP-4 inhibitors protect endothelial function through a GLP-1-dependent mechanism. However, the impact of these two types of drugs on endothelial dysfunction in patients with type 2 diabetes has not been fully elucidated. We compared the effects of sitagliptin, a DPP-4 inhibitor, and voglibose, an alpha GI, on endothelial function in patients with diabetes.

METHODS

We conducted a randomized prospective multicenter study in 66 patients with type 2 diabetes who did not achieve the treatment goal with sulfonylurea, metformin or pioglitazone treatment; 31 patients received sitagliptin treatment and 35 patients, voglibose treatment. The flow-mediated dilatation (FMD) of the brachial artery was measured in the fasting state at baseline and after 12 weeks of treatment. The primary endpoint was a change in FMD (ΔFMD) from the baseline to the end of follow-up. The effects of sitagliptin and voglibose on FMD were assessed by ANCOVA after adjustment for the baseline FMD, age, sex, current smoking, diabetes duration and body mass index. Secondary efficacy measures included changes in HbA1c, GIP, GLP-1, C-peptide, CD34, lipid profile, oxidative stress markers, inflammatory markers and eGFR and any adverse events.

RESULTS

ΔFMD was significantly improved after 12 weeks of treatment in both groups, and there was no significant difference in ΔFMD between the two groups. There were no significant differences in changes in HbA1c, GIP, GLP-1, C-peptide, lipid profile, oxidative stress marker, inflammatory marker and eGFR between the two groups. Compared with voglibose, sitagliptin significantly increased the circulating CD34, a marker of endothelial progenitor cells. Adverse events were observed in 5 patients in only the voglibose group (diarrhea 1, nausea 1, edema 2 and abdominal fullness 1).

CONCLUSIONS

Sitagliptin improved endothelial dysfunction just as well as voglibose in patients with type 2 diabetes. Sitagliptin had protective effects on endothelial function without adverse events.

TRIAL REGISTRATION

registered at http://www.umin.ac.jp/ctrj/ under UMIN000003951.

CD34+/CD45-dim stem cell mobilization by hyperbaric oxygen - changes with oxygen dosage

Because hyperbaric oxygen treatment mobilizes bone marrow derived-stem/progenitor cells by a free radical mediated mechanism, we hypothesized that there may be differences in mobilization efficiency based on exposure to different oxygen partial pressures. Blood from twenty consecutive patients was obtained before and after the 1st, 10th and 20th treatment at two clinical centers using protocols involving exposures to oxygen at either 2.0 or 2.5 atmospheres absolute (ATA). Post-treatment values of CD34+, CD45-dim leukocytes were always 2-fold greater than the pre-treatment values for both protocols. Values for those treated at 2.5 ATA were significantly greater than those treated at 2.0 ATA by factors of 1.9 to 3-fold after the 10th and before and after the 20th treatments. Intracellular content of hypoxia inducible factors -1, -2, and -3, thioredoxin-1 and poly-ADP-ribose polymerase assessed in permeabilized CD34+ cells with fluorophore-conjugated antibodies were twice as high in all post- versus pre-treatment samples with no significant differences between 2.0 and 2.5 ATA protocols. We conclude that putative progenitor cell mobilization is higher with 2.5 versus 2.0 ATA treatments, and all newly mobilized cells exhibit higher concentrations of an array of regulatory proteins.

A solitary fibrous tumour of the eyelid

OBJECTIVE

To report a case of palpebral solitary fibrous tumour (SFT).

CLINICAL PRESENTATION AND INTERVENTION

An elderly man presented with a slow-growing painless mass in the lower conjunctival fornix in the left eye. The lesion was excised and it measured 0.9 cm in maximum diameter. The microscopic features were characteristic of a benign SFT, with immunohistochemical reactivity for vimentin, CD34 and Bcl-2 protein. Nuclear staining for progesterone receptor was also observed.

CONCLUSION

This tumour displayed a benign course, with no recurrence after excision. CD34 immunohistochemistry proved to be a useful adjunct to the microscopic diagnosis.

Trichilemmoma arising in the nasal vestibule: report of three cases with special emphasis on the differential diagnosis

Trichilemmoma is a benign cutaneous epithelial tumor with differentiation towards cells of the outer hair root sheath and usually presents as a small papule on the face of middle-aged or older adults. We herein report three cases of trichilemmoma located in the nasal vestibule, including two of the conventional type and one of the desmoplastic variant. To our knowledge, only one case of trichilemmoma arising in the nasal vestibule has been previously reported. Trichilemmoma must be included in the differential diagnosis of epithelial lesions arising in this location. This is particularly important in the case of the desmoplastic trichilemmoma, a tumor that resembles invasive carcinoma such as desmoplastic squamous cell carcinoma, sclerosing basal cell carcinoma, and trichilemmal carcinoma. The circumscription of the lesion, the architectural pattern of epithelial cell cords and small nests merging with a desmoplastic stroma in the central area of the tumor, the expression of CD34, and the lack of an obvious squamous differentiation or basaloid foci favor the diagnosis of desmoplastic trichilemmoma. All these features help to rule out the diagnosis of carcinoma with significant clinical implications.

Benign fibrous histiocytoma arising from the right shoulder: Is immunohistochemical staining always required for a definitive diagnosis?

INTRODUCTION

Fibrous histiocytomas are divided into two subgroups: malignant and benign fibrous histiocytomas (BFHs). BFH is one of the most common tumors of the superficial and deep soft tissues; it is commonly found on the skin and presents as a slow-growing solitary nodule made up of a mixture of fibroblastic and histiocytic cells.

PRESENTATION OF CASE

In this study, we present the case of a 45-year-old female who was histopathologically diagnosed with dermatofibrosarcoma protuberans (DFSP) and received radiotherapy, but whose diagnosis was changed to BFH based on subsequent immunohistochemical analyses.

DISCUSSION

BFH is a mesenchymal soft-tissue tumor with fibroblastic and histiocytic differentiation. Differential diagnosis for BFH found in deeper tissues includes other aggressive fibrohistiocytic lesions, such as DFSP and malignant fibrous histiocytoma. Differentiating among these tumors is crucial in selecting the correct surgical strategy and patient management in the postoperative period. In most cases, the pleomorphism and atypical mitotic activity seen histopathologically are sufficient for the differentiation between benign and malignant tumors. Immunohistochemical staining methods should be used in cases that are difficult to diagnose. The treatment of choice for BFH is wide resection of the tumor, which results in an excellent prognosis and low recurrence rate. In agreement with cases reported in the literature, our case confirms that wide excision is adequate to prevent the recurrence of the tumor.

CONCLUSION

Although benign fibrous histiocytomas is rare, it must be considered in the differential diagnosis of tumors arising from the soft-tissue.

Immunohistochemical expression of PCNA and CD34 in colorectal adenomas and carcinomas using specified automated cellular image analysis system: a clinicopathologic study

BACKGROUND/AIM

To evaluate the immunohistochemical expression of proliferating cell nuclear antigen (PCNA) and CD34 in colorectal adenomas and carcinomas, and to correlate this expression with different clinicopathologic parameters.

MATERIALS AND METHODS

The study was retrospectively designed. A total of 86 tissue samples, including 33 paraffin blocks from patients with colorectal adenomas, 33 paraffin blocks from patients with colorectal adenocarcinomas, and a control group of 20 samples of nontumerous colonic tissue, were included in the study. From each block, 3 sections of 5 μm thickness were taken, 1 section was stained with hematoxylin and eosin (H and E) and the other 2 sections were stained immunohistochemically for PCNA and CD34. Scoring of the immunohistochemical staining was performed using a specified automated cellular image analysis system (Digimizer).

RESULTS

PCNA expression was significantly increased in a sequence of normal mucosa-adenoma-carcinoma. It was significantly higher in adenomas ≥ 1 cm and those with severe dysplasia, and it showed a significant positive correlation with grade and lymph node involvement in colorectal carcinoma. CD34 showed significantly higher expression in carcinoma than adenoma and in adenoma than in the control group. CD34 expression showed a significant correlation with adenomas carrying severe dysplasia and large-sized adenomas (≥1 cm). It was significantly correlated with tumor grade, lymphovascular invasion, and lymph node involvement in colorectal carcinoma.

CONCLUSION

PCNA plays an important role in colorectal neoplastic progression and can be utilized as ancillary marker for the risk of malignant transformation in colorectal adenomas as it correlates with high grade dysplasia and size. Intratumoral quantification of the mean (A and N) of CD34 in colorectal carcinoma reflects the grade of tumors and can predict lymph node involvement and lymphovascular invasion, to make a useful additional prognostic factor.

Identification and functional characterization of ion channels in CD34(+) hematopoietic stem cells from human peripheral blood

Hematopoietic stem cells (HSCs) are used therapeutically for hematological diseases and may also serve as a source for nonhematopoietic tissue engineering in the future. In other cell types, ion channels have been investigated as potential targets for the regulation of proliferation and differentiation. However, the ion channels of HSCs remain elusive. Here, we functionally characterized the ion channels of CD34(+) cells from human peripheral blood. Using fluorescence-activated cell sorting, we confirmed that the CD34(+) cells also express CD45 and CD133. In the CD34(+)/CD45(+)/CD133(high) HSCs, RT-PCR of 58 ion channel mRNAs revealed the coexpression of Kv1.3, Kv7.1, Nav1.7, TASK2, TALK2, TWIK2, TRPC4, TRPC6, TRPM2, TRPM7, and TRPV2. Whole-cell patch clamp recordings identified voltage-gated K(+) currents (putatively Kv1.3), pH-sensitive TASK2-like back-ground K(+) currents, ADP-ribose-activated TRPM2 currents, temperature-sensitive TRPV2-like currents, and diacylglycerol-analogue-activated TRPC6-like currents. Our results lend new insight into the physiological role of ion channels in HSCs, the specific implications of which require further investigation.

CD34 Antigen: Determination of Specific Sites of Phosphorylation In Vitro and In Vivo

CD34, a type I transmembrane glycoprotein, is a surface antigen which is expressed on several cell types, including hematopoietic progenitors, endothelial cells, as well as mast cells. Recently, CD34 has been described as a marker for epidermal stem cells in mouse hair follicles, and is expressed in outer root sheath cells of the human hair follicle. Although the biological function and regulation of CD34 is not well understood, it is thought to be involved in cell adhesion as well as possibly having a role in signal transduction. In addition, CD34 was shown to be critical for skin tumor development in mice, although the exact mechanism remains unknown.Many proteins' functions and biological activities are regulated through post-translational modifications. The extracellular domain of CD34 is heavily glycosylated but the role of these glycans in CD34 function is unknown. Additionally, two sites of tyrosine phosphorylation have been reported on human CD34 and it is known that CD34 is phosphorylated, at least in part, by protein kinase C; however, the precise location of the sites of phosphorylation has not been reported. In an effort to identify specific phosphorylation sites in CD34 and delineate the possible role of protein kinase C, we undertook the identification of the in vitro sites of phosphorylation on the intracellular domain of mouse CD34 (aa 309-382) following PKC treatment. For this work, we are using a combination of enzymatic proteolysis and peptide sequencing by mass spectrometry. After which the in vivo sites of phosphorylation of full-length mouse CD34 expressed from HEK293F cells were determined. The observed in vivo sites of phosphorylation, however, are not consensus PKC sites, but our data indicate that one of these sites may possibly be phosphorylated by AKT2. These results suggest that other kinases, as well as PKC, may have important signaling functions in CD34.

Analysis of angiogenic factors and cyclooxygenase-2 expression in cartilaginous tumors- clinical and histological correlation

OBJECTIVES

To study the role of angiogenesis and cyclooxygenase-2 expression in cartilaginous tumors and correlate these factors with prognosis.

INTRODUCTION

For chondrosarcoma, the histological grade is the current standard for predicting tumor outcome. However, a low-grade chondrosarcoma can follow an aggressive course-as monitored by sequential imaging techniques-even when it is histologically indistinguishable from an enchondroma. Therefore, additional tools are needed to help identify the biological potential of these tumors. The degree of angiogenesis that is induced by the tumor could assist in this task. Angiogenesis can be quantified by measuring the expression of vascular endothelial growth factor and CD34, and cyclooxygenase-2 can induce angiogenesis by stimulating the production of proangiogenic factors.

METHODS

In total, 21 enchondromas and 58 conventional chondrosarcomas were studied by examining the clinical and histopathological findings in conjunction with the immunostaining markers of angiogenesis and cyclooxygenase- 2 expression.

RESULTS

The significant variables that were associated with poor outcome were 1) higher-grade chondrosarcomas, 2) tumors that developed in flat bones, and 3) over-expression of CD34 (with a median count that was higher than 5.9 vessels in 5 high power fields). Moreover, CD34 expression (measured using the Chalkley method) revealed significantly higher microvessel density in flat bone chondrosarcomas.

DISCUSSION

Previous studies have shown a positive correlation between Chalkley microvessel density and histological grade; however, in our sample, we found that the former is predictive of the outcome. Chondrosarcomas in flat bones have been shown to correlate with a poor prognosis. We also found that CD34 microvessel density values were significantly higher in flat-bone chondrosarcomas. This could explain-at least in part-the more aggressive biological course that is taken by these tumors.

CONCLUSIONS

These results provide evidence that CD34 microvessel density in chondrosarcomas can be helpful in predicting patient outcome and may add to our understanding of chondrosarcoma pathogenesis.

Interstitial Cajal-like cells (ICLC) in atrial myocardium: ultrastructural and immunohistochemical characterization

We have previously reported (Hinescu & Popescu, 2005) the existence of interstitial Cajal-like cells (ICLC), by transmission electron microscopy, in human atrial myocardium. In the present study, ICLC were identified with non-conventional light microscopy (NCLM) on semi-thin sections stained with toluidine blue and immunohistochemistry (IHC) for CD117/c-kit, CD34, vimentin and other additional antigens for differential diagnosis. Quantitatively, on semi-thin sections, ICLC represent about 1-1.5% of the atrial myocardial volume (vs. approximately 45% working myocytes, approximately 2% endothelial cells, 3-4% for other interstitial cells, and the remaining percentage: extracellular matrix). Roughly, there is one ICLC for 8-10 working atrial myocytes in the intercellular space, beneath the epicardium, with a characteristic (pyriform, spindle or triangular) shape. These ICLC usually have 2-3 definitory processes, emerging from cell body, which usually embrace atrial myocytes (260 nm average distance plasmalemma/sarcolemma) or establish close contact with nerve fibers or capillaries (approximately 420 nm average distance to endothelial cells). Cell prolongations are characteristic: very thin (mean thickness = 0.15+/-0.1 microm), very long for a non-nervous cell (several tens of microm) and moniliform (uneven caliber). Stromal synapses between ICLC and other interstitial cells (macrophages) were found (e.g. in a multicontact type synapse, the average synaptic cleft was approximately 65 nm). Naturally, the usual cell organelles (mitochondria, smooth and rough endoplasmic reticulum, intermediate filaments) are relatively well developed. Caveolae were also visible on cell prolongations. No thick filaments were detected. IHC showed that ICLC were slightly and inconsistently positive for CD117/c-kit, variously co-expressed CD34 and EGF receptor, but appeared strongly positive for vimentin, along their prolongations. Some ICLC seemed positive for a-smooth muscle actin and tau protein, but were negative for nestin, desmin, CD13 and S-100. In conclusion, we provide further evidence of the existence of ICLC in human atrial myocardium, supporting the possible ICLC role in pacemaking, secretion (juxta- and/or paracrine), intercellular signaling (neurons and myocytes). For pathology, ICLC might as well be 'players' in arrhythmogenesis and atrial remodeling.

Bypass of senescence, immortalization, and transformation of human hematopoietic progenitor cells

We attempted to extend the lifespan of CD34+ stem/progenitor cells in human cord blood (CB) by transduction with lentiviral vectors carrying the human telomerase catalytic subunit (hTERT) and/or the human papillomavirus type 16 (HPV16) E6 and E7 oncogenes. We found that hTERT was incapable of prolonging the replicative capacity of CB cells maintained under serum-free conditions in the presence of stem cell factor, Flt3 ligand, thrombopoietin, and interleukin-3 beyond 4 months (n=3). However, transduced CB cells cultured in the same cytokine cocktail constitutively expressing HPV16 E6/E7 alone (n=2) or in concert with hTERT (n=9) continued to proliferate, giving rise to permanent (>2 years) cell lines with a CD45+ CD34- CD133+/- CD44+ CD235a+ CD71+ CD203+ CD33+ CD13+ myeloerythroid/mast cell progenitor phenotype. Notably, CB cell cultures expressing only HPV16 E6/E7 went through a crisis period, and the resulting oligoclonal cell lines were highly aneuploid. By comparison, the CB cell lines obtained by coexpression of HPV16 E6/E7 plus hTERT exhibited near-diploid karyotypes with minimal chromosomal aberrations, concomitant with stabilization of telomere length, yet were clonally derived. The immortalized E6/E7 plus hTERT-expressing CB cells were not tumorigenic when injected intravenously or subcutaneously into sublethally irradiated immunodeficient nonobese diabetic/severe combined immunodeficient mice but could be converted to a malignant state by ectopic expression of a v-H-ras or BCR-ABL oncogene. These findings provide new insights into the mechanisms governing the senescence checkpoint of primitive human hematopoietic precursors and establish a paradigm for studies of the multistep process of human leukemogenesis.

Transplantation of hematopoietic stem cells from the peripheral blood

Hematopoietic stem cells can be collected from the peripheral blood. These hematopoietic stem cells (HSC), or better progenitor cells, are mostly expressed as the percentage of cells than react with CD34 antibodies or that form colonies in semi-solid medium (CFU-GM). Under steady-state conditions the number of HSC is much lower in peripheral blood than in bone marrow. Mobilization with chemotherapy and/or growth factors may lead to a concentration of HSC in the peripheral blood that equals or exceeds the concentration in bone marrow. Transplantation of HSC from the peripheral blood results in faster hematologic recovery than HSC from bone marrow. This decreases the risk of infection and the need for blood-product support. For autologous stem-cell transplantation (SCT), the use of peripheral blood cells has completely replaced the use of bone marrow. For allogeneic SCT, on the other hand, the situation is more complex. Since peripheral blood contains more T-lymphocytes than bone marrow, the use of HSC from the peripheral blood increases the risk of graft-versus-host disease after allogeneic SCT. For patients with goodrisk leukemia, bone marrow is still preferred, but for patients with high-risk disease, peripheral blood SCT has become the therapy of choice.

Expression of c-kit and p53 in non-small cell lung cancers

PURPOSE

Increasing experimental evidence indicates that abnormal expression of c-kit may be implicated in the pathogenesis of a variety of solid tumors. It has been reported that over 70% of small cell lung cancer (SCLC) contain the c-kit receptor. In the present study, a c-kit analysis has been extended to non-small cell lung cancer (NSCLC). The expressions of p53, vascular endothelial growth factor (VEGF) and cd34, in addition to c-kit, were evaluated to investigate the correlations between these proteins and to determine their potential relationships with the clinicopathological data.

MATERIALS AND METHODS

Paraffin-embedded tumor sections, obtained from 147 patients with NSCLC, were immunohistochemically investigated using anti-c-kit, anti-p53, anti-VEGF and anti-cd34 antibodies.

RESULTS

c-kit was expressed in 40 (27%) of the tumors examined: 27% of the adenocarcinomas, 27% of the squamous cell carcinomas and 29% of the undifferentiated carcinomas. p53 and VEG F immunoreactivities were present in 107 (73%) and 110 (75%) carcinomas, respectively. Anti-cd34 was negative in all samples. No associations were established among these proteins. The c-kit, however, showed a strong correlation with the T factor: T1 (n=11), 0%; T2 (n=49), 16% and T3 (n=87), 37% (p=.006).

CONCLUSION

It is suggested that in NSCLC c-kit is expressed relatively frequently and may become a therapeutic target for the patients with inoperable or recurrent c-kit positive tumors. The alterations in p53 probably constitute an early event, whereas the activated c-kit may contribute to tumor progression.

There is more than one kind of myofibroblast: analysis of CD34 expression in benign, in situ, and invasive breast lesions

AIMS

Smooth muscle actin (SMA) positive myofibroblasts have been implicated in tumour invasion; however, acquisition of SMA is not limited to peritumorous fibroblasts and other changes in fibroblasts may be more specifically related to the malignant environment. CD34 is a sialomucin expressed by normal breast fibroblasts but lost in invasive carcinomas. The aim of this study was to establish the relation between CD34 and SMA expression in breast fibroblasts and to analyse whether loss of CD34 is specific for invasive disease.

METHODS

Immunohistochemistry for CD34 and SMA was performed on 135 cases including 10 normal, 10 fibroadenomas, 40 infiltrating ductal carcinomas, 55 cases of ductal carcinoma in situ (DCIS), and 20 radial scar/complex sclerosing lesions. The relation between staining pattern and histopathological features was recorded as positive, negative, or reduced.

RESULTS

Fibroblasts around all normal duct-lobule units and those showing epithelial hyperplasia were CD34 positive and mainly SMA negative. In fibroadenomas, fibroblasts retained CD34 but acquired SMA expression. In contrast, fibroblasts around invasive carcinoma were CD34 positive and SMA negative. In DCIS, loss of CD34 was significantly more frequent in high grade tumours than in low or intermediate grade ones (p < 0.001). The acquisition of SMA was seen more frequently than the loss of CD34, particularly in non-high grade DCIS. In all radial scars, fibroblasts were SMA positive but CD34 negative, and a similar pattern was seen in stromal cells in areas of fibrosis following core biopsy.

CONCLUSIONS

These results show that SMA positive myofibroblasts exhibit variable expression of CD34, indicating that these markers are not coordinately controlled. Loss of CD34 is strongly related to the malignant phenotype, in both invasive and preinvasive disease, but is not entirely specific because radial scar fibroblasts and fibroblasts in reactive fibrosis exhibit a similar phenotype. The functional relevance of altered CD34 expression is unclear but the very focal changes implicate local signalling mechanisms probably of epithelial origin.

Selective up-regulation of functional CXCR4 expression in erythroid cells by HIV-1 Tat protein

CXCR4 is the high affinity receptor for the SDF-1 alpha chemokine and represents the main coreceptor for HIV-1 T-tropic strains. The surface expression of CXCR4 was analysed in CD34+ haematopoietic progenitors, induced to differentiate along the erythroid or granulocytic lineages, in liquid cultures supplemented or not with HIV-1 Tat protein. At concentrations as low as 1-10 ng/ml, synthetic Tat protein significantly increased the surface expression of CXCR4 in erythroid but not in granulocytic cells. The Tat-mediated up-regulation of surface CXCR4 was accompanied by a concomitant increase of CXCR4 mRNA and total CXCR4 protein content in cells developing along the erythroid lineage after 6-10 days of culture. Moreover, addition of SDF-1 alpha (200 ng/ml) induced a significant higher rate of apoptosis in Tat-treated erythroid cells in comparison with control cells. These results demonstrated for the first time a direct positive role in haematopoietic gene regulation of Tat protein, and suggest the possible involvement of Tat in HIV-1-induced anaemia.

Expression of CD34 and Myf5 defines the majority of quiescent adult skeletal muscle satellite cells

Skeletal muscle is one of a several adult post-mitotic tissues that retain the capacity to regenerate. This relies on a population of quiescent precursors, termed satellite cells. Here we describe two novel markers of quiescent satellite cells: CD34, an established marker of hematopoietic stem cells, and Myf5, the earliest marker of myogenic commitment. CD34(+ve) myoblasts can be detected in proliferating C2C12 cultures. In differentiating cultures, CD34(+ve) cells do not fuse into myotubes, nor express MyoD. Using isolated myofibers as a model of synchronous precursor cell activation, we show that quiescent satellite cells express CD34. An early feature of their activation is alternate splicing followed by complete transcriptional shutdown of CD34. This data implicates CD34 in the maintenance of satellite cell quiescence. In heterozygous Myf5(nlacZ/+) mice, all CD34(+ve) satellite cells also express beta-galactosidase, a marker of activation of Myf5, showing that quiescent satellite cells are committed to myogenesis. All such cells are positive for the accepted satellite cell marker, M-cadherin. We also show that satellite cells can be identified on isolated myofibers of the myosin light chain 3F-nlacZ-2E mouse as those that do not express the transgene. The numbers of satellite cells detected in this way are significantly greater than those identified by the other three markers. We conclude that the expression of CD34, Myf5, and M-cadherin defines quiescent, committed precursors and speculate that the CD34(-ve), Myf5(-ve) minority may be involved in maintaining the lineage-committed majority.

Mesenchymal precursor cells in the blood of normal individuals

STATEMENT OF FINDINGS: Mesenchymal precursor cells found in the blood (BMPCs) of normal persons adhere to plastic and glass and proliferate logarithmically in DMEM-20% fetal calf serum (FCS) without growth factors. They form cells with fibroblast-like and stromal morphology, which is not affected by eliminating CD34, CD3, or CD14 cells. Osteogenic supplements (dexamethasone, ascorbic acid, and beta-glycerophosphate) added to the culture inhibited fibroblast formation, and BMPCs assumed the cuboidal shape of osteoblasts. After 5 days in supplemented medium, the elutriated cells displayed alkaline phosphatase (AP), and the addition of bone morphogenetic protein (BMP)2 (1 ng) doubled AP production (P < 0.04). Two weeks later, 30% of the cells were very large and reacted with anti-osteocalcin antibody. The same cultures also contained sudanophlic adipocytes and multinucleated giant cells that stained for tartrate-resistant acid phosphatase (TRAP) and vitronectin receptors. Cultured BMPCs immunostain with antibodies to vimentin, type I collagen, and BMP receptors, heterodimeric structures expressed on mesenchymal lineage cells. In addition, BMPCs stain with anti-CD105 (endoglin), a putative marker for bone-marrow mesenchymal stem cells (MSCs).

Vascular grading of angiogenesis: prognostic significance in breast cancer

The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11 years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers was moderately reproduced (kappa = 0.59). Vascular grade was significantly associated with axillary node involvement, tumour size, malignancy grade, oestrogen receptor status and histological type. In univariate analyses vascular grade significantly predicted recurrence free survival and overall survival for all patients (P < 0.0001), node-negative patients (P < 0.0001) and node-positive patients (P < 0.0001). Cox multivariate regression analysis showed that vascular grading contributed with independent prognostic value in all patients (P < 0.0001). A prognostic index including the vascular grade had clinical impact for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer.

CDK-inhibitor independent cell cycle progression in an experimental haematopoietic stem cell leukaemia despite unaltered Rb-phosphorylation

A CD34-negative haematopoietic progenitor cell line, D064, derived from canine bone marrow stromal cells is able to differentiate into haematopoietic progenitors under the influence of growth factor-mediated signalling. While differentiating, these cells eventually start to express MHC class II molecules (DR homologues) on their surface. The stable transfection of the fibroblast-like wild-type cells with retroviral constructs containing the cDNA for the canine MHC class II DR-genes (DRA and DRB) induces a change in morphology, accelerates cell cycle progression and leads to a loss of anchorage-dependent growth. Transfected cells show features of an immature stem cell leukaemia, such as giant cell formation. In wild-type D064 cells the accumulation of the cyclin-dependent kinase inhibitor (cdki) p27kip-1 induces differentiation, which is dependent upon signalling via the ligand for the tyrosine kinase receptor c-kit (stem cell factor). DR-transfected cells instead apparently grow independently of any growth factor-mediated signals and express high levels of the cdkis p27kip-1 and especially p21(waf-1/cip-1), concurrently with accelated cell cycle progression. In contrast to the overexpression of cdkis and despite accelerated cell cycle progression, the expression of the G2/M phase transition kinase p34cdc2 is significantly reduced in DR-transfected and transformed cells as compared to the haematopoietic wild-type cell line D064. This might suggest a possible alternative cell cycle progression pathway in this experimental stem cell leukaemia by by-passing the G0/G1 phase arrest, although retinoblastoma (Rb)-phosphorylation remains unaltered. These results provide evidence that mechanisms normally controlling the cell cycle and early haematopoietic differentiation are disrupted by the constitutive transcription and expression of MHC class II genes (DR) leading to a progression and growth of this experimental stem cell leukaemia independent from cell cycle controlling regulators such as p27 and p21.

Presence of circulating abnormal CD34+ progenitors in adult Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is related to the proliferation of cells, which are similar to Langerhans cells (LC) but possess many abnormal characteristics. Lesions are widespread and this fact suggests that LCH cells or their precursors are present in the blood of patients. In five adult patients, we have isolated and cultured CD34+ blood progenitors of dendritic cells. We studied their phenotype by flow cytometry and their functional properties in mixed culture with heterologous lymphocytes and with autologous lymphocytes in the presence of tri-nitro-phenyl antigen (TNP). The amount of CD34+ precursors was dramatically higher than controls but a high mortality occurred during the in vitro differentiation. The phenotype of surviving cells was similar to LC phenotype (CD1a+, CD83+, Lag+) but some of them expressed CD2. These cells were able to induce T cell proliferation in mixed culture. They could not initiate primary response to TNP, except in a patient treated with thalidomide. In our hands, these CD34+ cells may be precursors of LCH cells.

Identification of podocalyxin-like protein as a high endothelial venule ligand for L-selectin: parallels to CD34

The leukocyte adhesion molecule, L-selectin, mediates the recruitment of lymphocytes to secondary lymphoid organs via interactions with specific ligands presented on high endothelial venules (HEV). Although the HEV-derived ligands for L-selectin are still incompletely defined, they share a common sialomucin-like structure which is thought to present clustered oligosaccharides to the lectin domain of L-selectin. Podocalyxin-like protein (PCLP) is a transmembrane sialomucin that is similar in structure to the well-characterized L-selectin ligand CD34. PCLP has been shown previously to be expressed on the foot processes of podocytes in the kidney glomerulus as well as on vascular endothelium at some sites. We have determined that PCLP is present on HEV, where it binds to both recombinant L-selectin and the HEV-specific monoclonal antibody MECA-79. Furthermore, purified HEV-derived PCLP is able to support the tethering and rolling of lymphocytes under physiological flow conditions in vitro. These results suggest a novel function for PCLP as an adhesion molecule and allow the definition of conserved structural features in PCLP and CD34, which may be important for L-selectin ligand function.

Suppressive effect of LD78 on the proliferation of human hemopoietic progenitors

LD78 is a cDNA newly isolated from human stimulated tonsillar lymphocytes. The expression of LD78 is related to inflammatory responses and its structure has a homology with macrophage inflammatory protein 1-alpha, which is known to have an inhibitory effect on murine CFU-S. Using a colony assay technique, we examined the effects of LD78 on human hemopoietic progenitors. The addition of doses of 100 ng/ml or more of LD78 suppressed the colony formation of KMT-2, a factor-dependent myelomonocytic cell line established from cord blood cells; this suppressive activity was neutralized by the addition of antibody against LD78. The same doses of LD78 suppressed the formation of neutrophil, macrophage, and megakaryocytic colonies which were supported by human interleukin-3 and erythropoietin; however, LD78 did not affect colony formation by either non-phagocytic mononuclear cells or sorted CD34+ cells. The conditioned medium of KMT-2 cells or peripheral blood mononuclear cells cultured with LD78 suppressed colony formation by CD34+ cells. From these findings, it is suggested that LD78 affects phagocytic cells and induces factors that are inhibitory for hemopoiesis. We consider LD78 to be a new cytokine that plays an inhibitory role in hemopoiesis.