development of an ex vivo model to define the role of the igf-1 receptor in photocarcinogenesis

P7851Cutaneous metastasis from glioblastoma multiforme

Sevil Alan, MD, Akdeniz University Department of Dermatology and Venereology,Antalya, Turkey; Cumhur Ibrahim Bassorgun, MD, Akdeniz University School ofMedicine Department Of Pathology, Antalya, Turkey; Ethem G€oksu, MD, AkdenizUniversity School of Medicine Department of Neurosurgery, Antalya, Turkey

Glioblastoma multiforme (GBM) is the most malignant astrocytic tumor. 90% of thepatients lose their lives in 2 years after the diagnosis is made. Extracranial metastasisseldomly occurs. It is frequently misdiagnosed as a primary subcutaneous tumor. Inliterature, the number of declared cases about GBM’s skin metastasis are very few.Here, we presented a case of a high-grade GBM which made an appeal withformations like keloid on the old craniotomy scar and metastasized on the scalp.Pathology result of a patient, who had tumor resection with left frontal craniotomy 3years ago, was anaplastic astrocytoma grade 3. Later on, adjuvant radiotherapy andsimultaneous temozolomide chemotherapy were given. A year after the operationreoperation was made because of an observed relapse lesion, pathology wasreported as inactive tumor cells and reactive gliosis. 4 months later, awake surgicaloperation was performed again because of relapse lesion, this time pathology aftergross total resection was reported as glioblastoma multiforme (GBM grade 4). Thepatient admitted to us because of swollen, hard, skin-colored infiltrated papules onthe area that was compatible with incision scar on frontal craniotomy line. Thepatient was consulted to plastic surgery with keloid and skin metastasis prediag-noses, and patient’s biopsy results, which were taken from 4 ulcer nodular lesions,were reported as undifferential tumor (malign tumor metastasis) that presentsneuroendocrine differential. Within 2 months, 3 to 5 papules on the incision scarbecame a giangantic tumoral mass that covered the whole of the frontal scalp. Wepresent this case because it is a rarely seen mestastasis.

AB134

cial support: None identified.

P8217Development of an ex vivo model to define the role of the IGF-1 receptorin photocarcinogenesis

Rachel Ward, Indiana University School of Medicine, Indianapolis, IN, UnitedStates; Dan Spandau, PhD, Indiana University School of Medicine, Indianapolis,IN, United States; Jeffrey Travers, MD, PhD, Indiana University School ofMedicine, Indianapolis, IN, United States

The 2 most important risk factors for developing nonmelanoma skin cancer (NMSC)are exposure to the UVB component in sunlight and aging. The skin of geriatricindividuals is susceptible to UVB-induced DNA damage, which could result ininitiation of NMSC. Previous in vivo studies have demonstrated that the increasedsusceptibility to UVB-induced damage with age is caused by the silencing of insulin-like growth factor 1 (IGF-1) expression in dermal fibroblasts and the resulting failureto activate the IGF-1 receptor (IGF-1R) on epidermal keratinocytes. The objective ofthis study is to develop an in vitro model system using human skin to explicitlydelineate the mechanism of how IGF-1 silencing leads to NMSC initiation. Humanskin samples obtained from panniculectomy surgeries were grown ex vivo, treatedtopically with an IGF-1R inhibitor (or vehicle control) and UVB irradiated. Thesamples were then harvested at various times, formalin-fixed, paraffin-embedded,and 5-�M sections were examined via immunofluorescence for the presence ofthymine dimers (TD), indicative of DNA damage, and Ki67, a cellular proliferationfactor. Basal keratinocytes proliferating with DNA damage are indicative of aninappropriate, procarcinogenic response to UVB light, which is a precursor toNMSC. UVB-irradiated skin treated with the IGF-1R inhibitor (AG538) contained a10-fold increase in Ki67+:TD+ keratinocytes compared to the vehicle-treated UVB-irradiated tissue. These findings indicate that this model can be used as a surrogatefor geriatric skin. Consequently, similar studies have been conducted in immuno-deficient SCID mice, xenografted in the manner described above, which yieldedsimilar results. Long-term UVB studies using this model are currently underway.

cial support: None identified.

J AM ACAD DERMATOL

P8245Distal digital keratoacanthoma: Report of 2 cases

Maria Pilar P�erez Garc�ıa, Hospital Doctor Peset, Valencia, Spain; Almudena MateuPuchades, Hospital Doctor Peset, Valencia, Spain; Amparo Marquina Vila,Hospital Doctor Peset, Valencia, Spain; Celia Sanchis S�anchez, Hospital DoctorPeset, Valencia, Spain; Sof�ıa De As�ıs Cuestas, Hospital Doctor Peset, Valencia,Spain

Background: Distal digital keratoacanthoma (DKA) is a rare and destructive variantof keratoacanthoma (KA) that seldom regresses spontaneously. Distinguishingfeatures of DKA include pain, rapid growth, and early underlying bone destruction.Its importance lies in its similarity to squamous cell carcinoma. We report 2 cases ofthis entity attended in our service.

Case 1: A 57-year-old female presented with a painful subungual keratotic lesion inthe distal phalanx of the right first finger. The tumor had been developing for 2 yearswith no history of previous trauma or inflammation. Radiographic results showed anosteolytic area in the distal phalanx. Biopsy confirmed the diagnosis. We carried outa complete excision of the lesion, adopting a conservative approach.

Case 2: A 64-year-old man presented with a hyperkeratotic nodular lesion, with acharacteristic central keratin-filled crater, under the distal portion of the nail of thefirst finger of the right hand, of three months of evolution. The histologic study wascompatible with KA, with later resection of the whole tumor.

Conclusion: DKA should be considered in the differential diagnosis of painful lesionsof the distal phalanx. It consists of a keratotic or verrucous nodule in the nail bed atthe distal nail border, often in association with partial onycholysis. The hallmark ofDKA is its rapid growth, within a period of weeks; because of this, often causes boneerosion, which at radiographic examination appears as a cup-shaped defect of theterminal phalanx. The diagnosis of DKA should be based on the correlation ofclinical, radiologic, and pathologic findings. It is essential to recognize KA andseparate it from squamous cell carcinoma both for prognostic and therapeuticreasons. Conservative surgery is the first choice of treatment.

cial support: None identified.

P8532Effectiveness of a 595-nm pulsed dye laser for the treatment of basal cellcarcinoma using 1 stacked-pulse session

Sasima Eimpunth, MD, Department of Dermatology, Faculty of Medicine SirirajHospital, Bangkok, Thailand; Gagik Oganesyan, MD, PhD, Division ofDermatology, University of California, San Diego, San Diego, CA, United States;Michael Shane Hamman, MD, Division of Dermatology, University of California,San Diego, San Diego, CA, United States; Robert A. Lee, MD, PhD, Division ofDermatology, University of California, San Diego, San Diego, CA, United States;Shang I. Brian Jiang, MD, Division of Dermatology, University of California, SanDiego, San Diego, CA, United States; Soohyun Silvia Kim, University of California,San Diego School of Medicine, San Diego, CA, United States

Background: Treatment of basal cell carcinomas (BCCs) with pulsed-dye laser (PDL)has shown cure rates ranging from 62% to 91% when using multiple single passtreatments. Given the inconvenience of multiple visits, we conducted a pilot studyto investigate if nonmelanoma skin cancers could be treated with just a single PDLsession. The results from this small pilot study showed clearance rates of 71% (5/7).This study aims to conduct a larger scale study to determine statistical significanceand to validate the treatment of BCCswith a single PDL session using stacked-pulsedsetting.

Objective: To study the effectiveness and safety of a single stacked-pulse session onBCC treatment.

Methods: This was a prospective randomized study where 24 patients with biopsy-proven, superficial or nodular BCCs located on trunk or extremities were random-ized into 2 groups: laser-treatment group and control. Control group received notreatment and treatment group received one session of double stacked-pulses of PDLtreatment using 10 mm spot size, 3-ms pulse width, and a fluence of 7.5 J/cm2 at theoffice visit. Lesionswere treated with 1 single session and included a 6-mmmargin ofnormal skin around the clinically apparent tumor. Lesions were subsequentlyexcised and histologically evaluated. Adverse reactions were evaluated immediatelyafter the laser treatment and at the surgical excision visit.

Results: Twenty-four patients, 16 males and 8 females aged between 29-88 years oldwith a total of 24 tumors, participated in the study. There was a significant differencein the clearance rated for the BCCs between the control and treatment groups. Thetreatment group showed 71.4% (10/14) clearance whereas control group had 20%(2/10) clearance rate (P ¼ .01). Adverse events found immediately after the lasertreatment was purpura (100%) and at the surgical excision visit were blister (21.4%),dyspigmentation (21.4%), and 1 case of hypertrophic scar (7.14%).

Conclusion: These results show that single PDL session using double stacked-pulsedsetting may be a viable alternative to surgical and other nonsurgical modalities withsimilar clearance rates and adverse effects.

cial support: None identified.

MAY 2014