Diffuse large B cell lymphoma of hard palate: a case report with literature review

OBJECTIVE

Lymphomas are diverse group of neoplasm affecting the lymphoreticular system. Diffuse large B cell lymphoma is the most frequently diagnosed type of non-Hodgkin lymphoma and is the fifth most frequent malignancy, accounting for about 40% of cases reported. In the present case report a 40 year old female patient complains of swelling on right side of face since 45 days and gradually increased to present size. Intra-orally an ulcero-proliferative growth was present on the right side of hard palate. Incisional biopsy was suggestive of Lymphoproliferative disorder. Panel of immunohistochemical antibodies were used; which showed positivity for CD45, PAX5, Bcl2, Ki67, CD138 and negativity for CD3, CD10, CD20 and CD30. Therefore through routine standard hematoxylin and eosin staining a clear cut diagnosis of specific lymphoma was difficult to obtain and thus immunohistochemistry plays an important role in confirming the pinpoint diagnosis.

Aberrant expression of CD10 and BCL6 in mantle cell lymphoma

AIMS

Mantle cell lymphoma (MCL) is characterized by distinctive histological and molecular features. Aberrant expression of BCL6 and CD10 has been reported occasionally, but the biological features of such cases are largely unknown. This study aimed to define the epidemiological, histological and cytogenetic characteristics of BCL6 and CD10-positive MCLs, also investigating possible biological features.

METHODS AND RESULTS

A total of 165 cases of cyclin D1 and t(11;14)(q13;q34)-positive MCLs were studied for CD10 and BCL6 immunohistochemical expression, which was documented in 26 of 165 (15.8%) cases (BCL6 17 of 165; CD10 11 of 165; BCL6 and CD10 co-expression two of 165). CD10-positivity was significantly more frequent in females (63.3%; P < 0.01). Either expression correlated significantly with higher mean proliferation index and higher prevalence of MUM1 positivity (P < 0.05). Fluorescence in-situ hybridization (FISH) for BCL6 (3q27) gene derangements was performed on the BCL6- and CD10-positive cases and 98 matched controls: amplifications were documented more frequently in BCL6-positive than -negative cases (50.0% versus 19.4% of cases) (P < 0.05). The mutational status of the variable immunoglobulin heavy chain genes (IGVH) was investigated by Sanger sequencing: five of the six successfully tested cases (83.3%) showed no somatic hypermutations.

CONCLUSIONS

Aberrant CD10 and BCL6 expression defines a subset of MCLs with higher mean Ki-67 index and higher prevalence of MUM1 expression. BCL6 protein positivity correlates with cytogenetic aberrations involving the BCL6 gene. Although examined successfully in few cases, the high prevalence of unmutated IGVH genes also points at a pregerminal cell origin for these phenotypically aberrant cases.

C-kit positive intraosseous myoepithelioma arising in rib: a case report

We describe a rare intraosseous myoepithelioma, arising in a rib. The patient was a 14-year-old female. The tumor, composed of epitheliod cells and plump spindle cells, was immunopositive for AE1/AE3, S-100 protein, HHF-35, desmin, smooth muscle actin (SMA), CD10, and c-kit, indicating a diagnosis of myoepithelioma. The tumor had invaded surrounding soft tissues, indicating a locally aggressive tumor. Positive staining for CD10 supported the diagnosis of myoepithelioma. To our knowledge, c-kit immunoreactivity has not been reported in intraosseous myoepithelioma. This form of myoepithelioma, arising in a rib and showing c-kit positivity, is very rare.

Primary cutaneous perivascular epithelioid cell tumor (PEComa): Five new cases and review of the literature

PEComas represent a family of uncommon mesenchymal tumors composed of "perivascular epithelioid cells" with a distinct immunophenotype that typically shows both myogenic and melanocytic differentiation. The PEComa family includes angiomyolipoma (AML), clear cell "sugar" tumor of the lung and extra pulmonary sites, lymphangioleiomyomatosis and clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres. Very rarely, PEComas may arise in the skin. Primary cutaneous PEComas typically display a dermal proliferation of epithelioid cells with pale, clear, or granular pink cytoplasm arranged in nests and trabecula with an intervening arborizing network of delicate capillaries. Primary cutaneous PEComas have a lower frequency of myogenic marker expression than their deep soft tissue and visceral counterparts. They also often express strong diffuse CD10, leading to potential confusion with metastatic renal cell carcinoma. Most cases behave indolently. We report 5 additional cases of this rare entity. All showed classic histologic features and expression of either HMB-45 and/or Melan-A/MART-1. Four cases were tested for myogenic markers (2 were positive & 2 were negative). Three cases were tested for CD10 (all 3 were positive). All of our cases with clinical follow-up behaved indolently. Table 1 provides a summary of findings for all 5 cases in our series.

Undifferentiated Uterine Sarcoma: An Uncommon Case Report

Endometrial Stromal Sarcomas (ESS) are rare uterine malignancy of mesodermal origin. A 65-year-old female presented with postmenopausal bleeding in the Department of Gynaecology in our hospital. Computed Topography (CT) revealed an enlarged uterus with areas of low attenuation. On gross appearance endometrial cavity was distorted with an irregular friable necrotic mass. Histopathologically, it was diagnosed as undifferentiated uterine sarcoma. Rhabdoid, osteoid and cartilaginous differentiation were found along with osteoclast like giant cells. Immunohistochemistry was strongly positive for CD10.

Flow cytometric detection of minimal residual disease in B-lineage acute lymphoblastic leukemia by using "MRD lite" panel

BACKGROUND

Normal B lymphoid precursors that express CD19, CD10, and/or CD34 are highly sensitive to corticosteroids and after two weeks of remission-induction therapy, they form less than 0.01% of the bone marrow population. More than 0.01% of such cells indicate minimal residual disease (MRD). MRD "lite" panel uses only three antibodies, namely CD19, CD10, and CD34 for MRD detection in cases of B-lineage acute lymphoblastic leukemia (B-ALL) expressing CD19, CD10, and/or CD34 by flow cytometry.

METHODS

Fifteen cases of B-ALL were studied for MRD at Day 19 of remission-induction therapy by employing a simplified MRD detection protocol using a 3-color fluorochrome conjugated antibody panel (CD19, CD10, and CD34) on bone marrow aspirate samples.

RESULTS

All cases at diagnosis expressed CD19, CD10, and CD34. Of fifteen patients, five (33.33%) were MRD negative with less than 0.01% of mononuclear cells and remaining ten cases (66.66%) were MRD positive, with the level of 0.01% to less than 0.1% cells.

CONCLUSION

The MRD assay used in this study is a simplified method for detecting MRD at Day 19 of remission-induction therapy for B-lineage ALL. This MRD assay is an effective and useful methodology in cases of B-ALL expressing CD19, CD10, and/or CD34 by flow cytometry.

Ectopic Gastric and Intestinal Phenotypes, Neuroendocrine Cell Differentiation, and SOX2 Expression Correlated With Early Tumor Progression in Colorectal Laterally Spreading Tumors

INTRODUCTION

The significance of the ectopic gastric phenotype remains unclear in patients with colorectal laterally spreading tumors (LSTs). We investigated clinicopathologic differences among LST subtypes, aiming to identify factors indicative of malignant transformation and invasion that are linked to ectopic gastric phenotype and tumor progression.

MATERIALS AND METHODS

We analyzed the morphologic characteristics of 105 colorectal LSTs resected by endoscopic submucosal dissection. LSTs were classified into 2 subtypes: granular (G-LST) and nongranular (NG-LST). Resected LSTs were analyzed histologically and were immunohistochemically stained for MUC5AC, MUC6, chromogranin A, CD10, and SOX2.

RESULTS

The 105 LSTs included 60 G-LSTs and 45 NG-LSTs. By histology, G-LSTs comprised 5 adenomas with low-grade dysplasia (LAs), 45 adenomas with high-grade dysplasia (HAs), and 10 adenocarcinomas invading the submucosa (SMs). NG-LSTs comprised 8 LAs, 25 HAs, and 12 SMs. MUC5AC positivity was significantly higher in G-LSTs compared to NG-LSTs (P = .002), and MUC5AC positivity in HA lesions was significantly higher than in LA lesions (P = .01). MUC6 and SOX2 positivity in SM G-LSTs, and chromogranin A positivity in SM NG-LSTs were significantly higher than in HAs (P = .01, .01, and .03, respectively). CD10 positivity in SM NG-LSTs was significantly higher than in HAs and LAs (P = .02 and .01, respectively).

CONCLUSION

Ectopic gastric and intestinal phenotypes, neuroendocrine cell differentiation, and SOX2 expression differ according to tumor grade in colorectal LSTs, and these markers are correlated with early tumor progression in each LST subtype.

CD10 down expression in follicular lymphoma correlates with gastrointestinal lesion involving the stomach and large intestine

Follicular lymphoma (FL) shows co-expression of B-cell lymphoma 2 (BCL2) and CD10, whereas downexpression of CD10 is occasionally experienced in gastrointestinal (GI) FL with unknown significance. Gastrointestinal FL is a rare variant of FL, and its similarity with mucosa-associated lymphoid tissue lymphoma was reported. We investigated the clinicopathological and genetic features of CD10 downexpressed (CD10^down ) GI-FL. The diagnosis of CD10^down FL was carried out with a combination of pathological and molecular analyses. The incidence of CD10^down GI-FL was shown in 35/172 (20.3%) cases, which was more frequent than nodal FL (3.5%, P < 0.001). The difference was additionally significant between GI-FL and nodal FL when the analysis was confined to primary GI-FL (55.2% vs 3.5%, P < 0.001). Compared to CD10⁺ GI-FL, CD10^down GI-FL significantly involved the stomach or large intestine (P = 0.015), and additionally showed the downexpression of BCL6 (P < 0.001). The follicular dendritic cell meshwork often showed a duodenal pattern in the CD10^down group (P = 0.12). Furthermore, a lymphoepithelial lesion was observed in 5/12 (40%) gastric FL cases, which indicated caution in the differentiation of mucosa-associated lymphoid tissue lymphoma. Molecular analyses were undertaken in seven cases of CD10^down GI-FL, and an identical clone was found between CD10^down follicles and CD10⁺ BCL2⁺ neoplastic follicles. In the diagnosis of cases with CD10^down BCL2⁺ follicles, careful examination with molecular studies should be carried out.

CD10 and CD138 can be expressed in giant cell tumor of bone: An immunohistochemical study

Giant cell tumor of bone (GCTB) is a primary bone neoplasm which is characterized by the presence of mononuclear cells (MCs) and osteoclast-like multinucleated giant cells (MNGCs). Up to our knowledge, CD10 immunoreactivity in GCTB has not yet been studied, and only one study touched on CD138 immunoreactivity in GCTB. The objective of this study is to investigate the immunoreactivity of CD10 and CD138 in GCTB. We offer a discussion of our findings in the context of the differential diagnosis, particularly in small biopsy material. We retrieved and reviewed 15 well-documented cases of GCTB from January 2008 to December 2014. Well-controlled standard immunohistochemical satins were performed on these cases for CD10 and CD138 and few other selected antibodies. Immunoreactivity for CD10 was membranous and was found in 14 (93%) cases. This immunoreactivity was found only in the MCs, whereas the MNGC were all negative. CD138 showed variable positivity in 11 (73%) while 4 (37%) were completely negative. Similar to CD10, staining for CD138 was only seen in the MC; however, the immunoreactivity was predominantly concentrated in the peri-vascular areas. Most of GCTB cases can show variable immunoreactivity for CD10 and CD138. The aforementioned immune-expression raise the possibility of a role in the pathogenesis of GCTB. Paying attention to this immunoreactivity is recommended when considering the clinical and radiological differential diagnosis, especially in small biopsy specimens.

Immunophenotypic and diagnostic characterization of angioimmunoblastic T-cell lymphoma by advanced flow cytometric technology

Angioimmunoblastic T-cell lymphoma (AITL) often shows systemic symptoms related to immune dysregulation and cytokine production. Biopsy usually harbors few malignant cells in an abundant reactive background, which can be diagnostically challenging in cases with small biopsies. This study was performed to assess the value of flow cytometry (FC) and to determine the immunophenotypic alterations in 155 samples from 38 patients with AITL. FC detected an aberrant T-cell population in 97 of 155 samples that represented 0.5-90% of lymphocytes. Blood was involved in 11 of 16 patients. The most frequent immunophenotypic aberrancies included loss of CD3; altered T-cell receptor expression and aberrant CD10 expression. Altered CD3 expression was more frequently seen in peripheral blood (PB) and bone marrow (BM), whereas aberrant CD10 expression was more common in lymph node (LN). AITL cells often exhibit abnormal CD4⁺ immunophenotype with diminished or absent CD3 and variable CD10 expression. Multiparameter FC is an effective tool for supporting the diagnosis of AITL in any fluid and various tissue specimens types.

IFITM1 Is Superior to CD10 as a Marker of Endometrial Stroma in the Evaluation of Myometrial Invasion by Endometrioid Adenocarcinoma

Background: Distinguishing myometrial invasion from adenomyosis involvement is important for staging of endometrial endometrioid adenocarcinoma. We aimed to compare CD10, which has limited value in this scenario, with interferon-induced transmembrane protein 1 (IFITM1), a recently described sensitive and specific marker of endometrial stroma.

Methods: We reviewed 25 hysterectomies containing endometrial endometrioid adenocarcinoma and adenomyosis. Tumor areas were classified as unequivocally myoinvasive or unequivocally noninvasive. Foci equivocal for invasion were also recorded. Immunohistochemistry for IFITM1 and CD10 was performed and scored in terms of intensity and distribution and classified as negative or positive.

Results: Unlike CD10, IFITM1 staining showed significant differences in mean intensity (P < .0001) and distribution (P < .0001) between invasive vs noninvasive areas. Sixteen (84.2%) invasive and 34 (97.1%) noninvasive areas were positive for CD10 (P = .22). In contrast, none of the invasive vs 25 (71.4%) noninvasive areas were positive for IFITM1 (P < .0001). IFITM1 had 71.4% sensitivity and 100% specificity in detecting stroma surrounding endometrioid adenocarcinoma, hence excluding myoinvasion. Eleven (45.8%) of 24 foci designated as equivocal stained with IFITM1.

Conclusions: Compared with CD10, IFITM1 has superior performance distinguishing endometrial stroma of adenomyosis from mesenchyma surrounding invasive endometrial adenocarcinoma. IFITM1 expression is highly predictive of the absence of invasion and may be valuable in cases in which determining myoinvasion has staging implications.

Gene Expression Profiling Supports the Neural Crest Origin of Adult Rodent Carotid Body Stem Cells and Identifies CD10 as a Marker for Mesectoderm-Committed Progenitors

Neural stem cells (NSCs) are promising tools for understanding nervous system plasticity and repair, but their use is hampered by the lack of markers suitable for their prospective isolation and characterization. The carotid body (CB) contains a population of peripheral NSCs, which support organ growth during acclimatization to hypoxia. We have set up CB neurosphere (NS) cultures enriched in differentiated neuronal (glomus) cells versus undifferentiated progenitors to investigate molecular hallmarks of cell classes within the CB stem cell (CBSC) niche. Microarray gene expression analysis in NS is compatible with CBSCs being neural crest derived-multipotent progenitor cells able to sustain CB growth upon exposure to hypoxia. Moreover, we have identified CD10 as a marker suitable for isolation of a population of CB mesectoderm-committed progenitor cells. CD10 + cells are resting in normoxia, and during hypoxia they are activated to proliferate and to eventually complete maturation into mesectodermal cells, thus participating in the angiogenesis necessary for CB growth. Our results shed light into the molecular and cellular mechanisms involved in CBSC fate choice, favoring a potential use of these cells for cell therapy. Stem Cells 2016;34:1637-1650.

Significance of androgen receptor and CD10 expression in cutaneous basal cell carcinoma and trichoepithelioma

Differential diagnosis of trichoepithelioma (TE) and basal cell carcinoma (BCC) on the basis of clinical symptoms and laboratory investigations may be difficult in certain patients. The aim of the present study was to compare cluster of differentiation 10 (CD10) and androgen receptor (AR) expression patterns in BCC and TE, to investigate the predictive power of these proteins as markers of the two conditions. A total of 39 cases of BCC and 15 cases of TE were retrieved from the pathology department archives. AR and CD10 immunohistochemistry was performed on all of the specimens; 23 BCC cases displayed focal nuclear AR staining, however, none of the cases demonstrated diffuse nuclear staining and 16 BCC cases were negative for AR staining. Stromal CD10 staining was more common in TE cases than in BCC cases, and peripheral CD10 staining was more common in BCC cases than in TE cases. AR immunostaining of the BCC samples typically appeared as scattered clusters and individual cells. In addition, AR and CD10 staining exhibited varying staining intensities within each samples. Incisional punch biopsy specimens have the potential to present false-negative results. Therefore, AR and CD10 staining of total excision biopsies provides a more accurate differential diagnosis of BCC and TE for cases with difficulties in the histopathological analysis.

Diagnostic value of CD10 and Bcl2 expression in distinguishing cutaneous basal cell carcinoma from squamous cell carcinoma and seborrheic keratosis

The distinction between cutaneous basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and seborrheic keratosis (SK), which are common entities in clinical practice, can be difficult clinically and histologically. CD10 and Bcl2 antigens are important factors in tumor growth, survival and spread. The aim of the present study is to define the frequency of CD10 and Bcl2 expression in such cutaneous tumors and its relation to the clinicopathological characteristics as well as their possible diagnostic utility. CD10 and Bcl2 immunohistochemistry was performed on 30 BCC, 20 SCC and 15 SK. 93.3% of SK cases and 53.3% of BCC cases showed significant expression of CD10 in tumor cells when compared either with each other or with SCC cases (100% negative). Stromal CD10 expression was positive in 50% of BCC cases and 75% of SCC cases. Stromal CD10 expression was significantly higher in high risk BCC and BCC with infiltrating deep margins; furthermore, it showed a significant positive correlation with grade of SCC. A significant inverse correlation between CD10 expression in stromal and tumor cells of BCC was present. Bcl2 was significantly expressed in 93.3% of SK cases and 80% of BCC cases when compared with SCC cases (100% negative). It was found that for distinguishing BCC from SK, only CD10 expression in tumor cells provided a high diagnostic value with positive likelihood ratio (PLR) was 7.00. In addition, CD10 and Bcl2 expression in tumor cells could give convincing diagnostic value to distinguish SCC from SK (PLR=15.00 for each marker). Moreover, for differentiating BCC from SCC, only Bcl2 in the tumor cells could provide a high diagnostic value (PLR=5.5). In conclusion, CD10 and Bcl2 can help in differentiating cutaneous BCC from SK and SCC. The overexpression of CD10 in the stromal cells of SCC and some variants of BCC suggests the invasive properties of such tumors.

Shadow cell differentiation from squamoid morule in endometrial adenoacanthoma

Shadow cell differentiation (SCD), commonly found in cutaneous pilomatricoma (PMX), has been said to be extremely rare in extracutaneous tumors and its morphogenesis has not been clarified yet. In the present study, 25 cases of endometrial adenoacanthoma were examined with special reference to SCD and with immunohistochemistry for beta-catenin and CD10. Shadow cell nests (SCNs) were observed in 2 out of 5 cases of adenocarcinoma with squamoid morules and all of 4 cases of adenocarcinoma with squamous differentiation and morules, but not in any cases of adenocarcinoma with squamous differentiation. SCNs were just adjacent to morules with or without a mutual transition. Immunohistochemical examination revealed nuclear accumulation of beta-catenin and expression of CD10 in the squamoid morules around SCNs. These results indicate that SCNs are derived from squamoid morules in endometrial adenoacanthoma, and established a link between matrical basaloid cells in PMX and squamoid morules in endometrial adenoacanthoma, as common original tissues, showing nuclear accumulation of beta-catenin and expression of CD10, of SCNs. It seems that SCD is not so uncommon as previously estimated in endometrial adenoacanthoma.

CD10, BCL6, and MUM1 expression in diffuse large B-cell lymphoma on FNA samples

BACKGROUND

Gene expression profiling has divided diffuse large B-cell lymphoma (DLBCL) into 2 main subgroups: germinal center B (GCB) and non-GCB type. This classification is reproducible by immunohistochemistry using specific antibodies such as CD10, B-cell lymphoma 6 (BCL6), and multiple myeloma oncogene 1 (MUM1). Fine-needle aspiration (FNA) plays an important role in the diagnosis of non-Hodgkin lymphoma, and in some cases FNA may be the only available pathological specimen. The objectives of the current study were to evaluate CD10, BCL6, and MUM1 immunostaining on FNA samples by testing the CD10, BCL6, and MUM1 algorithm on both FNA cell blocks (CB) and conventional smears (CS), evaluating differences in CB and CS immunocytochemical (ICC) performance, and comparing results with histological data.

METHODS

Thirty-eight consecutive DLBCL cases diagnosed by FNA were studied. Additional passes were used to prepare CB in 22 cases and CS in 16 cases; the corresponding sections and smears were immunostained using CD10, BCL6, and MUM1 in all cases. The data obtained were compared with histological immunostaining in 24 cases.

RESULTS

ICC was successful in 33 cases (18 CB and 15 CS) and not evaluable in 5 cases (4 CB and 1 CS). The CD10-BCL6-MUM1 algorithm subclassified DLBCL as GCB (9 cases) and non-GCB (24 cases). ICC data were confirmed on histologic staining in 24 cases.

CONCLUSIONS

CD10, BCL6, and MUM1 ICC staining can be performed on FNA samples. The results herein prove it is reliable both on CB and CS, and is equally effective and comparable to immunohistochemistry data.

Follicular lymphoma (in situ) pattern in the bone marrow: does it indicate an early stage in disease evolution?

Bone marrow involvement by an isolated interstitial lymphoid aggregate exhibiting the pattern and phenotype described for follicular lymphoma in situ (FLIS) has not been reported before. The detection of clinically silent FL in this case highlights the necessity of complete staging workup when such lesions are encountered in biopsies.

[A tumor of the vagina not to overlook, the mesonephric adenocarcinoma: about a case report and review of literature]

L'adénocarcinome mésonéphrique du vagin est une tumeur maligne extrêmement rare avec uniquement trois cas publiés dans la littérature jusqu’à maintenant. Il dérive des reliquats embryonnaires des canaux mésonéphriques au niveau du vagin. Nous rapportons un cas d'adénocarcinome mésonéphrique du vagin survenant chez une femme de 50 ans, et révélé par une masse polyploïde du vagin. L'IRM a montré un envahissement du périnée et de la branche inférieure du pubis. L’étude anatomo-pathologique était en faveur d'un adénocarcinome mésonéphrique dont les cellules tumorales expriment la pancytokératine et le CD10. Elles ne sont pas marquées par les anticorps anti récepteurs ostrogéniques et progestatifs. La patiente a été adressée pour radiothérapie avant la prise en charge chirurgicale. Les auteurs soulignent à travers cette observation les aspects étiopathogéniques, histologiques et thérapeutiques de cette tumeur rare.

Tumoral CD10 expression correlates with high-grade histology and increases risk of recurrence in patients with stage I lung adenocarcinoma

OBJECTIVE

CD10 (neutral endopeptidase) is expressed in various normal and tumor cells, and its biological function can be controlled through enzymatic activity and signaling pathways. We investigated whether CD10 expression predicted disease recurrence and whether it correlated with histologic subtypes of stage I lung adenocarcinoma.

MATERIALS AND METHODS

We reviewed tumor slides of resected pathologic stage I lung adenocarcinomas (1995-2009). Tumors were classified according to the IASLC/ATS/ERS classification. CD10 immunohistochemistry was performed using tissue microarrays (n=915). We combined the intensity (0-3) and distribution scores (0-2) for CD10 to create a total score (0-5). Risk of recurrence was estimated using competing risks methods.

RESULTS

In the training cohort (n=313), risk of recurrence of patients with high tumoral CD10 (score>1, n=57) was significantly higher (5-year cumulative incidence of recurrence [CIR], 37%) than in those with low CD10 (score≤1; n=256; 5-year CIR, 16%; P<0.001); this finding was confirmed in the validation cohort (n=602, P=0.036). High tumoral CD10 was associated with higher risk of recurrence in acinar (P=0.007) and papillary predominant tumors (P=0.022). High tumoral CD10 was most frequently identified in micropapillary predominant (41%) and solid predominant tumors (34%). On multivariate analysis of intermediate-grade tumors, high tumoral CD10 remained a significant independent risk factor of recurrence (hazard ratio, 1.88; P=0.025).

CONCLUSION

In stage I lung adenocarcinoma, tumoral CD10 correlated with high-grade histology and was an independent predictor of recurrence in intermediate-grade tumors.

Quantification of regenerative potential in primary human mammary epithelial cells

We present an organoid regeneration assay in which freshly isolated human mammary epithelial cells are cultured in adherent or floating collagen gels, corresponding to a rigid or compliant matrix environment. In both conditions, luminal progenitors form spheres, whereas basal cells generate branched ductal structures. In compliant but not rigid collagen gels, branching ducts form alveoli at their tips, express basal and luminal markers at correct positions, and display contractility, which is required for alveologenesis. Thereby, branched structures generated in compliant collagen gels resemble terminal ductal-lobular units (TDLUs), the functional units of the mammary gland. Using the membrane metallo-endopeptidase CD10 as a surface marker enriches for TDLU formation and reveals the presence of stromal cells within the CD49f(hi)/EpCAM(-) population. In summary, we describe a defined in vitro assay system to quantify cells with regenerative potential and systematically investigate their interaction with the physical environment at distinct steps of morphogenesis.

Gastric carcinoma with an invasive micropapillary carcinoma component showing HER2 gene amplification and CD10 expression: a case report and review of the literature

An 81-year-old man was referred to our hospital because gastric cancer was detected on screening esophagogastroduodenoscopy. Surgical resection of the tumor was performed. It was 25 × 20 mm in size and swollen lymph nodes were present nearby. Lymphadenectomy was also performed. Histopathologically, the tumor reached the proper muscle layer via venous invasion. There were three components that constituted the tumor, that is, 40% of mass was invasive micropapillary carcinoma (IMPC), 40% was papillary adenocarcinoma and 20% tubular adenocarcinoma. Vascular invasion was prominent. Immunohistochemistry revealed that the tumor showed an entirely intestinal mucin phenotype, being positive only for CD10 and negative for MUC2, MUC5AC, and MUC6. HER2 staining score ranged from 2+ to 3+, depending on the components described above. HER2 gene amplification was present in all the components according to dual-color in situ hybridization. The metastatic lymph nodes were similar to the primary site in morphology and immunohistochemistry, but HER2 amplification was higher in the lymph nodes. The IMPC component with HER2 amplification is rarely seen and its positivity for CD10 is an unexpected finding for gastric IMPC. Hence, this is a highly unusual case judging by the literature; further studies are needed to clarify the nature of gastric IMPC.

Primary extrauterine endometrial stromal sarcoma in the sigmoid colon

An endometrial stromal sarcoma (ESS) is an uncommon uterine neoplasm, and its primary occurrence in the intestine as an extrauterine ESS (EESS) is exceedingly rare. We hereby report a primary EESS arising in the sigmoid colon with a review of the literature. A 52-year-old woman presented with bloody stool and underwent a colon fiberscopy, which revealed a fungating mass obstructing the lumen at the distal sigmoid. A laparoscopic low anterior resection was performed, and an umbilicated polypoid mass was identified; on section, it had infiltrated the mesocolic fat and measured 3.8 cm × 2.5 cm. The tumor showed geographic sheets or nests composed of relatively monotonous stromal cells, expansion or infiltration to the proper muscle and mesocolic fat, and extensive lymphovascular invasion and metastasis to regional lymph nodes and the pelvic peritoneum. The tumor cells were strongly and diffusely immunoreactive for CD10, but negative for c-kit, CD34, and Dog1. Two months later, a hysterectomy with a bilateral salpingo-oophorectomy was performed, and no evidence of an ESS was found in the uterus.

CD10 is useful to identify gastrointestinal contamination in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytology from pancreatic ductal adenocarcinoma

OBJECTIVE

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytology is an effective tool to diagnose pancreatic ductal adenocarcinoma (PDA). Standard morphological criteria are usually reliable. When contaminating gastrointestinal (GI) epithelial cells are prevalent among neoplastic cells, these can be highlighted by carcinoembryonic antigen (CEA) staining. CD10 is a cell-surface metallopeptidase normally expressed by the GI epithelial apical border, whose expression is decreased or lost in PDA. We included CD10 in a panel, together with CEA, to discriminate the GI contaminant cells from PDA cells on cell blocks.

METHODS

Eight cases of EUS-FNA of PDA, featuring both contaminating GI cells and neoplastic cells, whose corresponding cell blocks were available for immunostaining, were selected. CD10 and CEA were stained on cell blocks by standard methods.

RESULTS

CD10 strongly labelled only the GI cells, with a well-defined apical membrane signal; conversely, GI cells did not show CEA staining; benign duodenal cells were faintly labelled in only one case. Malignant cells were positive for CEA and negative for CD10, with the exception of one case with labelled neoplastic cells with weak diffuse cytoplasmic positivity. CD10 apical membrane staining was a feature only seen in benign GI cells.

CONCLUSIONS

As a loss of CD10 is a consistent feature of PDA, this marker can be useful, together with CEA, to aid the cytopathologist to identify neoplastic cells in a background rich in GI contaminant cells.