cutaneous paraneoplastic syndromes include acanthosis nigricans , the sign of leser - trlat , eruptive acrochordons , acquired ichthyosis , erythroderma , palmoplantar hyperkeratosis , acquired hypertrichosis lanuginosa , erythema gyratum repens , necrolytic migratory erythema , bazex 's syndrome and dermatomyositis . the presence of either syndrome in patients warrants evaluation for a possible underlying malignancy . here
we report the case of a 79-year - old man , who developed numerous several centimeter - large seborrheic keratoses on his chest and back within the time period of one year .
workup led to the diagnosis of colonic adenocarcinoma , underscoring the paraneoplastic etiology of the seborrheic keratoses in this patient .
a 79-year - old man with a previous diagnosis of chronic lymphocytic leukemia was seen for preoperative evaluation prior to elective right peripatellar bursectomy after having failed antibiotic treatment . on physical examination
numerous seborrheic keratoses in a christmas tree pattern   were noted on his chest and back ( fig .
the patient reported that the lesions had appeared and advanced within the past twelve months on his trunk .
he was seen by a dermatologist , who suggested performing endoscopies of the upper and lower gastrointestinal tract .
the patient had not noted clinical symptoms otherwise suggestive of colon cancer , such as unintentional weight loss or recent change of bowel habits .
the clinical presentation of the seborrheic keratoses in this patient was found to be consistent with the sign of leser - trlat .
leser - trlat is a rare dermatologic finding named after two surgeons , the german edmund leser ( 18281916 ) and the french ulysee trlat ( 18271890 ) .
however , the first descriptions of patients with characteristic signs of leser - trlat were published in 1900   and 1901 by the german dermatologist eugen hollnder .
the leser - trlat sign is characterized by the sudden onset of multiple seborrheic keratoses or an unusually rapid increase in size and number of preexisting seborrheic keratoses , occasionally on an inflammatory base .
it is commonly associated with malignancies , primarily gastrointestinal adenocarcinomas [ 5 , 6 ] , but also squamous cell carcinomas , leukemias and lymphomas .
although patients with nonmalignant conditions , such as pregnancy , hiv infection   or after having received heart transplantation , can also develop seborrheic keratoses of florid eruption , the term leser - trlat usually implies paraneoplasia .
the significance of this sign has been debated in the medical literature , as leser - trlat is observed primarily in elderly individuals , who are statistically at higher risk for developing both seborrheic keratoses as well as various malignancies .
therefore , accurate diagnosis is linked to the rapidity of onset of seborrheic keratoses , and to the growth behavior of previously noted seborrheic keratoses . only rarely has leser - trlat been reported in younger patients .
the seborrheic keratoses seen in leser - trlat differ neither morphologically nor histologically from commonly seen seborrheic keratoses .
they are found predominantly on back and chest of patients , and there is no predilection for patients gender or ethnic / ancestral background .
the most prevalent clinical symptom is pruritus , seen in 43% of malignant cases [ 12 , 13 ] . in approximately 20% of cases
acanthosis nigricans is also present , either at the time of cancer diagnosis or it develops subsequently . while the pathogenesis of this condition is unclear and remains to be elucidated , due to the proliferative nature of cutaneous paraneoplasias ,
a possible pathogenic role of epidermal growth factor and alpha - transforming growth factor in the development of the seborrheic keratoses associated with malignancies has been hypothesized and reported . on rare occasions , skin manifestations similar to the leser - trlat sign
can be mimicked by malignant melanoma , thus justifying excision biopsies and histologic examinations of suspicious lesions in distinct cases .
florid eruption or abnormally fast growth of seborrheic keratoses especially in elderly patients should always raise the suspicion for an underlying malignant disease , in particular for gastrointestinal adenocarcinomas . performing an endoscopic evaluation of the gastrointestinal tract of affected patients
 we report the case of a 79-year - old caucasian man , who developed numerous pruritic seborrheic keratoses on his chest and back within one year . 
 an underlying malignant disease was suspected . 
 upper and lower endoscopies were performed and the patient was diagnosed with adenocarcinoma of the ascending colon . 
 we discuss the clinical significance of his cutaneous symptoms / signs , and review the medical literature on the paraneoplastic sign of leser - trlat . 
Introduction
Case Report
Discussion
Conclusion
Disclosure Statement