Flow Cytometry of Nonhematopoietic Neoplasms

Abstract

Many epithelial neoplasms can be analyzed by flow cytometry (FC), particularly from serous cavity effusion samples, using EpCAM, a cell adhesion molecule expressed on most normal epithelial cells and expressed at a higher level in most epithelial neoplasms. A simple 3-color flow cytometric panel can provide a high sensitivity and specificity compared to cytomorphology. FC provides more rapid immunophenotyping than conventional immunohistochemical staining, can identify rare malignant cells that could be missed by a cytological exam alone, and can be utilized to evaluate limited samples such as cerebrospinal fluid or fine-needle aspiration samples. Flow cytometric analysis for epithelial antigens can be combined with DNA ploidy analysis or assessment of the nucleus-to-cytoplasm ratio. Panels of flow cytometric markers are useful for the assessment of pediatric nonhematopoietic neoplasms, including neuroblastomas, primitive neuroectodermal tumors, Wilms' tumor, rhabdomyosarcomas, germ cell tumors, and hemangiopericytomas, as well as small-round-blue-cell tumors in adults, including small-cell carcinomas.

Flow cytometry identification of nonhemopoietic neoplasms during routine immunophenotyping

“…The 7AAD dye was used to exclude dead cells, as damaged cells (frequently observed in samples involved by metastasis) may negatively affect FC results . NHNs were identified by a combination of qualitative and quantitative criteria that take into account the preliminary immunophenotyping results and the “unusual” distribution of CD45− events in the scatter plot (physical parameters) as clearly described by Pillai and Dorfman “ ….while hematopoietic elements occupy well‐established regions in the forward versus side scatter plot, epithelial elements are variable in size and cytoplasmic complexity and may be present in any region of the forward versus side scatter plot .” Scatter parameters and back gating of CD326− or CD56− or CD138‐positive events were fundamental to detect NHNs, though neoplastic cells have heterogeneous cell size and granular cell content, and can therefore be found in all areas of the FS/SS plot, including the region usually not considered when analysing haematological diseases (being generally occupied by cell debris) . The present findings highlight that the described approach enabled to detect cells either of epithelial or nonepithelial origin.…”

Flow Cytometry in Pediatric Malignancies

“…Flow cytometry is not used routinely in the diagnosis or follow-up of non-hematopoietic neoplasms; however, many non-hematopoietic neoplasms and tissues are amenable to flow cytometric analysis, especially serous cavity effusions and limited fine-needle aspirate (FNA) or cerebrospinal fluid (CSF) samples [19]. It is possible to differentiate various non-hematopoietic malignancies with use of certain markers like EpCAM (Ber-EP4, CD326, and MOC31), CD45, CD56, CD71, CD81, CD9, MyoD1, Myogenin, CD99 and CD271.…”

“…For instance, most carcinomas would be EpCAM+, CD45-, CD14-, while neuroblastomas would have the following profile: CD56hi, GD2+, CD81+, CD9+, CD45-. Rhabdomyosarcomas on the other hand would also express MYOD1+, myogenin+ [2,19]. In fact based on the following markers CD45, CD56, CD90, EpCAM, CD34, Myogenin and MyoD1, an algorithm for differentiating various small round cell tumours can be followed.…”

“…Therefore, multiparameter flow cytometric immunophenotyping has been primarily used to provide rapid diagnosis and help classify most of the hematological malignancies, including pediatric leukemias and lymphomas, where there is blood and/or marrow involvement, as well as body fluid samples like cerebrospinal fluid, pleural fluid and peritoneal fluid, etc. Pediatric solid tumors, like small round cell tumors (SRCT), and nodal lymphomas are increasingly being subjected to flow cytometry, both for diagnosis and classification [3]. In addition, flow cytometry is also being used for evaluation of tumor cell DNA contents and cell cycle analysis [2].…”

‘Six Memos' for Lymph Node Fine-Needle Cytology and Flow Cytometry

“…FNC-FC provides a significant contribution to EUS/EBUS, and the advantages of this application are widely reported in the article by Jin and Wakely [14]. The diagnosis of lymphoproliferative processes is the main application of FNC-FC but, given that FNC is a first-line procedure in LN enlargement, the occurrence of metastases or tumors of unknown nature or origin may occur, and FC is extremely helpful in these cases [15]. Moreover, whereas NHL diagnosis and classification are crucial points of LN pathology, the identification of nonneoplastic, reactive LN enlargements has a greater clinical relevance, both to avoid useless biopsies and to identify possible causes and specific agents.…”