Erythroplasia of Queyrat (EQ)  is an uncommon carcinoma in situ, which usually occurs in the mucosa of glans penis, originally reported by Queyrat in 1911. The commonest form of EQ is being premalignant lesion with progression rate of about 30%. Clinically, it appears as a persistent well-circumscribed erythematous lesion of the glans but differential diagnosis with Balanitis, Bowens Disease is made by histopathological report  . Thus Histopathological Examination plays a significant role in diagnosis and management of the disease. The standard protocol for management should be by Immquimod, fluorouracil and Invasive approach should be adopted if conservative therapy causes no improvement.
2. Case Report
51 years, Male presented with reddish rash on the tip of penis since 6 months. Irritative and eroding in nature and has been persistent with gradual increase-
Figure 1. Glistening cherry red lesion noted on the tip of penis.
Figure 2. Histopathological report: (a) HE × 40 showing acanthosis, slight derangement of stratum spinosum and basement membrane integrity. (b) HE × 100 showing visible nuclear hyper chromatic cells, and pathological karyokinesis & dyskeratotic cells.
ment of the lesion. Onexamination, glistening cherry red lesion noted on the tip of penis as shown in Figure 1(a), Figure 1(b). HPE report (Figure 2(a), Figure 2(b); Hematoxylin & Eosin Stain, with 40 & 100 magnifying power): Acanthosis, slight derangement of stratum spinosum, basement membrane integrity, visible nuclear hyper chromatic cells, and pathological karyokinesis & dyskeratotic cells. Patient was treated with photodynamictherapy (PDT) twice.
EQ   is Squamous cell carcinoma in situ of penis usually involving glans and prepuce, commonly found in uncircumcised men with progression into invasive carcinoma in about 30% of cases.
Clinical features depend upon case to case, some are presented late.
Modalities of treatment depend upon the clinical onset of the disease; early presentation with small lesions can be treated conservatively. Currently, Immiquimod  being the most frequently used drug, even 5-Fluorouracil has promising result. If the conservative approach fails then more aggressive (Invasive)   approach should be adopted.
Course of Action
Patient was given Photo Dynamic Therapy and post therapy; subject was followed up for every 1 month with slight improvement in subsequent visit.
 Stables, G.I., Stringer, M.R. and Robinson, D.J. (1999) Erythroplasia of Queryrat Treated by Topical Aminolaevulinic Acid Photodynamic Therapy. British Journal of Dermatology, I40, 514-517.