Pseudoepitheliomatous hyperplasia mimicking invasive squamous cell carcinoma in extranodal natural killer/T‐cell lymphoma: a report of 34 cases. Issue 3 (23rd March 2015)

• Record Type: Journal Article
• Authors: Ling, Yi‐Hong; Zhu, Chong‐Mei; Wen, Shi‐Hong; Luo, Rong‐Zhen; Li, Peng; Cao, Yun; Rao, Hui‐Lan; Lin, Su‐Xia; Cai, Mu‐Yan
• Is Part Of: Histopathology. Volume 67:Issue 3(2015)
• Page Start: 404
• Page End: 409
• Publication Date: 2015-03-23
• Subjects: Histology, Pathological -- Periodicals; 611.018
• DOI: 10.1111/his.12656
• Languages: English
• ISSNs: 0309-0167

Abstract

<abstract abstract-type="main" id="his12656-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="his12656-sec-0001" sec-type="section"> <title>Aims</title> <p>Pseudoepitheliomatous hyperplasia (PEH) is defined as a pattern of epidermal reaction. However, it has not yet been extensively documented in extranodal natural killer/T‐cell lymphoma (ENKTL). The aim of our study was to analyse a series of ENKTLs concomitant with PEH mimicking squamous cell carcinoma (SCC).</p> </sec> <sec id="his12656-sec-0002" sec-type="section"> <title>Methods and results</title> <p>We analysed 34 cases of ENKTL with PEH. In our study, the incidence of PEH was 3.8% in ENKTLs diagnosed over a 13‐year period. All 34 cases presented with PEH, appearing as tongue‐like projections of squamous epithelium into the underlying submucosa/dermis with variable depths and jagged borders. The keratinocytes sometimes showed a minor degree of cytological atypia, mostly in the stratum basale, and keratinocyte necrosis was absent. Atypical mitoses and a high nuclear/cytoplasmic ratio were absent. The submucosa and the squamous cell cords were also permeated by atypical lymphocytes.</p> </sec> <sec id="his12656-sec-0003" sec-type="section"> <title>Conclusions</title> <p>ENKTL can be associated with PEH, and the atypical lymphoid cell population can be highly subtle, and therefore may be easily mistaken for SCC, leading to inappropriate therapy. A correct diagnosis requires awareness and recognition of this pitfall by recognizing the associated conditions listed above, which distinguish PEH from SCC.</p> </sec> </abstract>