Abstract 1091: A new image processing approach for functional context-based analysis of tryptase positive mast cells in cutaneous T-cell lymphomas
Authors: Rogojanu Radu , Eder Johanna , Jerey Waltraud , Klosner Gabriele , Paulitschke Verene , Ellinger Isabella , Thalhammer Theresia , Kolmer Dan , Trautinger Franz 
Published: August 2015

Quantification data on mast cells is scarce in primary cutaneous T-cell lymphomas (CTCL), a heterogeneous group of non-Hodgkin lymphomas with initial presentation in the skin. The aim of the study was to develop a new whole-slide in-silico analysis method for immunohistochemistry stained skin sections. The design of the analysis method was focused on results about structural context of the cell location distribution and cell morphometry linked to mast cell activation states.

Immunohistochemistry staining with a monoclonal anti-mast cell tryptase antibody was performed on paraffin embedded biopsies from patients with different CTCL subtypes and controls (normal skin, inflammatory skin diseases),while hematoxylin was used for counter staining. Slides were scanned with a TissueFAXS 200 Cytometer (TissueGnostics GmbH, Vienna). Whole-slide digital images were analyzed using StrataQuest 5.0 Advanced (TissueGnostics, Vienna).

Hematoxylin+ cell nuclei and tryptase+ cells (TRYP+) objects were automatically detected using the available analysis modules with adaptive segmentation of color-deconvoluted images. Mast cells were first selected as brown-positive cells in a peri-nuclear compartment, then further stratified depending on the spatial distribution of brown-positive dots inside the cellular compartment. In an additional analysis layer, an algorithm pipeline for the identification of the epidermis / dermis area was assembled. Density-based CTCL areas were segmented in a third independent pipeline. Inside dermis, two additional CTCL-proximity masks were defined at 0-30μm away from CTCL (P1 mask), as well as in the 30-60μm interval (P2 mask).

Typically, there were more mast cells inside CTCL areas than in P1, which in turn had less than the P2 mask. This distribution was especially noticed in Mycosis fungoides(MF) IIB, where CTCL had 2-3 times more mast cells than P1 mask had. However, this trend was not consistent in all types of lymphoma. Interestingly, MF IIA had a different distribution showing more mast cells in P1 than in CTCL areas.

The new algorithms provided a rich data insight on functional context-based characteristics and propose new surrogate markers for further characterization of CTCL. The analysis time needed for statistically relevant large whole-slide tissue sections was drastically reduced when using the computer-aided approach when compared against full manual annotation and counting. Moreover, distance assessment and morphometry parameter quantification for each cell are only feasible in in-silico approaches.

Note: This abstract was not presented at the meeting.

Citation Format: Radu Rogojanu, Johanna Eder, Waltraud Jerey, Gabriele Klosner, Verene Paulitschke, Isabella Ellinger, Theresia Thalhammer, Dan Kolmer, Franz Trautinger. A new image processing approach for functional context-based analysis of tryptase positive mast cells in cutaneous T-cell lymphomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1091. doi:10.1158/1538-7445.AM2015-1091