Mast Cells Are Abundant in Primary Cutaneous T-Cell Lymphomas: Results from a Computer-Aided Quantitative Immunohistological Study

PLoS One. 2016 Nov 28;11(11):e0163661. doi: 10.1371/journal.pone.0163661. eCollection 2016.


Background: Mast cells (MC) are bone marrow derived haematopoetic cells playing a crucial role not only in immune response but also in the tumor microenvironment with protumorigenic and antitumorigenic functions. The role of MC in primary cutaneous T-cell lymphomas (CTCL), a heterogeneous group of non-Hodgkin lymphomas with initial presentation in the skin, is largely unknown.

Objective: To gain more accurate information about presence, number, distribution and state of activation (degranulated vs. non-degranulated) of MC in CTCL variants and clinical stages.

Materials and methods: We established a novel computer-aided tissue analysis method on digitized skin sections. Immunohistochemistry with an anti-MC tryptase antibody was performed on 34 biopsies of different CTCL subtypes and on control skin samples. An algorithm for the automatic detection of the epidermis and of cell density based CTCL areas was developed. Cells were stratified as being within the CTCL infiltrate, in P1 (a surrounding area 0-30 μm away from CTCL), or in P2 (30-60 μm away from CTCL) area.

Results: We found high MC counts within CTCL infiltrates and P1 and a decreased MC number in the surrounding dermis P2. Higher MC numbers were found in MF compared to all other CTCL subgroups. Regarding different stages of MF, we found significantly higher mast cell counts in stages IA and IB than in stages IIA and IIB. Regarding MC densities, we found a higher density of MC in MF compared to all other CTCL subgroups. More MC were non-degranulated than degranulated.

Conclusion: Here for the first time an automated method for MC analysis on tissue sections and its use in CTCL is described. Eliminating error from investigator bias, the method allows for precise cell identification and counting. Our results provide new insights on MC distribution in CTCL reappraising their role in the pathophysiology of CTCL.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Case-Control Studies
  • Cell Degranulation
  • Female
  • Humans
  • Image Processing, Computer-Assisted / methods
  • Immunohistochemistry / methods
  • Lymphoma, T-Cell, Cutaneous / pathology*
  • Male
  • Mast Cells / pathology*
  • Mast Cells / physiology
  • Middle Aged
  • Mycosis Fungoides / pathology
  • Skin Neoplasms / pathology
  • Young Adult

Grant support

Georg Steiner is co-owner and founder of TissueGnostics. TissueGnostics supported the project by scanning and by developing software algorithms for the analysis of the slides. Georg Steiner did not influence the data and data interpretation. Writing of the manuscript was done without Georg Steiners influence. Radu Rogujanu is an employee of Tissue Gnostics Gmbh and is paid a salary from TissueGnostics Gmbh. Radu Rogujau and Georg Steiner acknowledge financial support from the EC Marie Curie Actions, AIDPATH project (num. 612471). The funder provided support in the form of salaries for authors [RR], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the 'author contributions' section.