New cell block containing agarose for cytopathological diagnosis of tumor samples

Cell blocks in cytology: review of preparation methods, advantages, and limitations

Cell blocks are cytologic preparations that are processed as paraffin embedded blocks in a manner comparable to formalin-fixed paraffin-embedded tissue in surgical pathology. In addition to serving as an adjunct to other cytologic preparations for morphologic diagnosis, cell blocks play an increasingly important role as they yield tissue sections that can be utilized for ancillary testing such as immunohistochemical stains and molecular studies. While essentially universally viewed as playing a pivotal role in cytopathology practice, there are various factors that limit their use in practice and contribute to dissatisfaction with cell block quality. Cell block preparation, as opposed to tissue processing in surgical pathology, is more variable with many different protocols in use today. This review explores the most commonly used cell block preparation techniques currently in use with review of the unique advantages and limitations each method presents. The goal of this work is to serve as a resource that can aid in making more informed decisions about which cell block protocol may work best for individual laboratories.

CXCL12 loaded-dermal filler captures CXCR4 expressing melanoma circulating tumor cells

Development of distant metastasis relies on interactions between cancer and stromal cells. CXCL12, also known as stromal-derived factor 1α (SDF-1α), is a major chemokine constitutively secreted in bone marrow, lymph nodes, liver and lung, playing a critical role in the migration and seeding of neoplastic cells. CXCL12 activates the CXCR4 receptor that is overexpressed in several human cancer cells. Recent evidence reveals that tumors induce pre-metastatic niches in target organ producing tumor-derived factors. Pre-metastatic niches represent a tumor growth-favoring microenvironment in absence of cancer cells. A commercially available dermal filler, hyaluronic acid (HA) -based gel, loaded with CXCL12 (CLG) reproduced a "fake" pre-metastatic niche. In vitro, B16-hCXCR4-GFP, human cxcr4 expressing murine melanoma cells efficiently migrated toward CLG. In vivo, CLGs and empty gels (EGs) were subcutaneously injected into C57BL/6 mice and 5 days later B16-hCXCR4-GFP cells were intravenously inoculated. CLGs were able to recruit a significantly higher number of B16-hCXCR4-GFP cells as compared to EGs, with reduced lung metastasis in mice carrying CLG. CLG were infiltrated by higher number of CD45-positive leukocytes, mainly neutrophils CD11b+Ly6G+ cells, myeloid CD11b+Ly6G- and macrophages F4/80. CLG recovered cells recapitulated the features of B16-hCXCR4-GFP (epithelial, melanin rich, MELAN A/ S100/ c-Kit/CXCR4 pos; α-SMA neg). Thus a HA-based dermal filler loaded with CXCL12 can attract and trap CXCR4+tumor cells. The CLG trapped cells can be recovered and biologically characterized. As a corollary, a reduction in CXCR4 dependent lung metastasis was detected.

Aquaporin-1 expression in fluoro-edenite-induced mesothelioma effusions: An approach by cell-block procedure

OBJECTIVE

Aquaporin 1 (AQP-1) is a water channel protein found in cell membranes, whose expression has been considered an independent favourable prognostic factor in pleural malignant mesothelioma (MM). The aim of this study was to evaluate the expression of AQP-1 and its prognostic value in a series of pleural MM effusions, from a geographical area with high concentrations of fluoro-edenite (FE).

METHODS

We selected 25 MM cases from Biancavilla (Italy), an area with high environmental concentrations of FE. Cytological samples, cell-blocks (CB), clinical and follow-up data were available for all cases. Immunohistochemistry for calretinin, CK5/6, WT1, CK7 and TTF1 was used on CB sections to confirm the cytological diagnosis of MM. Immunohistochemistry for AQP-1 was performed and high expression was defined when ≥50% of tumour cells showed linear and circumferential membranous staining.

RESULTS

The cohort included 16 men and nine women (median age: 67.5 years; range: 49-88 years). The median survival was 14 months (range 1.5-60 months), with a significant value (P = 0.006). All cases have been histologically confirmed and classified as epithelioid (16 cases), biphasic (seven cases) and sarcomatoid (two cases). AQP-1 high expression has been observed in 16 cases. Comparing AQP-1 high expression to the survival of corresponding patients, a significant association with a slight increased overall survival of 12 months has been demonstrated. Nine patients with a AQP-1 score less than 50% showed a shorter median overall survival (7 months).

CONCLUSIONS

AQP-1 high expression is detectable on cytological samples of FE-induced MM with a prognostic value.