Sign of Leser-Trélat.

To cite: Chakradeo K, Narsinghpura K, Ekladious A. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2016215316 DESCRIPTION An 87-year-old woman presented with severe iron deficiency anaemia (haemoglobin 57 g/L). She also described a recent increase in the number of pigmented skin lesions on her trunk, which had become mildly pruritic. Her history included a right hemicolectomy 12 years earlier for tubulovillous adenoma and suspicion of malignant transformation. At that time, her serum carcinoembryonic antigen (CEA) had been normal and resection histology revealed complete margins with no evidence of malignancy. Unfortunately, she had declined colonoscopy surveillance following this. On examination, she was found to have extensive seborrhoeic keratoses, which had recently increased in size and number (figure 1). Although the patient preferred to avoid colonoscopy, further investigations for an underlying malignancy were pursued. A CT scan of the abdomen showed suspicious bowel thickening suggestive of colorectal malignancy (figures 2 and 3) and a serum CEA was markedly elevated (167 mg/L). These findings supported not only a diagnosis of colorectal malignancy but also the suggestion of the sign of Leser Trélat. Sign of Leser–Trélat is a rare finding of sudden eruption of seborrhoeic keratoses associated with malignancies, usually gastrointestinal adenocarcinoma. 2 The most reported malignancies associated with Leser–Trélat sign are adenocarcinoma of the stomach, colon or rectum, 4 followed by breast cancer, lymphoma and lung cancer. It is thought to be caused by various cytokines and growth factors produced by the neoplasm. 5 Seborrhoeic keratoses can also be seen in older patients without malignancy, and an abrupt appearance of seborrhoeic keratoses without malignancy has been referred to as a pseudo-sign of Leser–Trélat. Although this sign has been debated due to the common occurrence of seborrhoeic keratoses in the elderly, it is also well described in young patients with underlying cancer, which helps validate it as a true cutaneous paraneoplastic phenomenon. This case highlights the importance of considering malignancy in the differential diagnosis of patients who present with new and extensive seborrhoeic keratoses so that prompt investigation, diagnosis and subsequent management can occur.