Hypertrophic Lichen Planus versus Well-Differentiated Squamous Cell Carcinoma: A Histological Challenge 

Main Article Content

Samuel P Haslam
Lindy S Ross
Alison C Lowe
Brent C Kelly


hypertrophic lichen planus, lichen planus, squamous cell carcinoma, well-differentiated squamous cell carcinoma, dermatopathology, immunohistochemistry, histology


Differentiating hypertrophic lichen planus (LP) from well-differentiated squamous cell carcinoma (SCC) is a histological challenge given the numerous histopathologic similarities between SCC and pseudoepitheliomatous hyperplasia (PEH) arising in the setting of hypertrophic LP. Multiple reports have shown that SCC can arise from hypertrophic LP not infrequently, but that the LP-to-SCC sequence is poorly understood, and many cases defy diagnosis due to histologic similarities. However, there are several clinical clues and histopathologic details that have shown to have some value when trying to ascertain the correct diagnosis. To the contrary, immunohistochemical tests have shown little promise in differentiating hypertrophic LP from SCC. Although multiplex PCR has shown some potential in differentiating PEH from SCC, this has only been in the setting of patients diagnosed with prurigo and lichen simplex chronicus, but not necessarily in the case hypertrophic LP. 


1. Nguyen R, Murray B, McCormack C. Hypertrophic lichen planus: masquerading as squamous cell carcinoma. Clinical Dermatology. 2014;2(3):136-9.

2. Knackstedt TJ, Collins LK, Li Z, Yan S, Samie FH. Squamous cell carcinoma arising in hypertrophic lichen planus: a review and analysis of 38 cases. Dermatol Surg. 2015;41(12):1411-8.

3. Tan E, Malik R, Quirk CJ. Hypertrophic lichen planus mimicking squamous cell carcinoma. Australas J Dermatol. 1998;39(1):45-7.

4. Pusiol T, Zorzi MG, Morichetti D, Speziali L. Pseudoepitheliomatous hyperplasia arising from hypertrophic lichen planus mimicking squamous cell carcinoma: limited value of immunohistochemistry. Acta Dermatovenerol Croat. 2012;20(2):112-25.

5. Deal T, Mishra V, Duong B, Andea A. Pitfalls in dermatopathology: when things are not what they seem. Expert Rev Dermatol. 2012;7(6):579-88.

6. Su A, Ra S, Li X, Zhou J, Binder S. Differentiating cutaneous squamous cell carcinoma and pseudoepitheliomatous hyperplasia by multiplex qRT-PCR. Modern Pathology. 2013;26;1433-7.

7. Bedir R, Yilmaz R, Sehitoglu I, Ozgur A. Coexistence of granular cell tumor with squamous cell carcinoma on the tongue: a case report. Iran J Otorhinolaryngol. 2015;27(78):69-74.