Journal of Clinical and Aesthetic Dermatology

Updates on Psoriasis & Cutaneou Oncology

An evidence-based, peer-reviewed journal for practicing clinicians in the field of dermatology

Issue link: http://jcadonline.epubxp.com/i/882293

Contents of this Issue

Navigation

Page 29 of 43

S30 P r o c e e D i n G s JCAD jOUrnAl Of ClInICAl And AEsthEtIC dErMAtOlOgy september 2017 • volume 10 • number 9 • supplement surgical wound. this may require a smaller microscope head with an automated approach so that the entire wound can be imaged in a rapid, controlled manner. lM is a subtype of melanoma in situ, characterized by a lentiginous growth pattern of melanocytes as solitary units at the dermal- epidermal junction (DeJ) of chronically photodamaged skin. lM may have ill-defned borders and possible (and signifcant) subclinical extension. it can be challenging to preoperatively delineate lM because it occurs against the background of sun-damaged skin and there can be intrinsic, early changes in the tumor, which is composed of a single atypical melanocytic proliferation. 1 65 in a study of 29 patients with lM, margins were frst obtained clinically using dermoscopic examination, and then rcM was used to obtain margins in no more than four radial directions per patient. in this study population, there were 4 out of 29 false positives where rcM-diagnosed lM could not be confrmed histologically. there were also 5 out of 29 false negatives, where lM could be confrmed histologically but was not evident with rcM. 165 rcM may also be used to monitor how lM responds to nonsurgical treatments, such as imiquimod. in a study, rcM could identify 70 percent of all imiquimod responders with no false negatives, which puts it roughly on par with histopathology. 165 for freshly excised tumors, ex-vivo fcM can be used with diderent guorophores at varying wavelengths (the most commonly used is acridine orange, which provides excellent contrast). for Bcc, fcM correlates well with frozens, odering 88-percent sensitivity and 99- percent specifcity. it may even oder more information in that fcM can help analyze fat tissues and other structures that could be altered in frozen Mohs processing. the fundamental limitations of ex-vivo fcM is that it can be challenging to recognize the cords and strands of infltrative Bcc and distinguish them from stroma. sebaceous glands may be diecult to identify and may be confused with basaloid islands. 165 fcM technology continues to evolve and improve, with the potential for a wide range of applications for dermatologists. image databases could one day be set up and connected to artifcial intelligence systems to allow for real-time diagnosis and to help guide treatments. Melanoma. subclinical spread describes the microscopic tumor extension beyond the margin, which can result in positive margins with wide local excision and may be associated with local recurrence, both of which complicate melanoma management. 166 MMs and related techniques can be used for more rigorous subclinical tumor identifcation for certain types of melanoma, but the clinical factors associated with the subclinical spread of in-situ melanoma remain to be elucidated. that frequency of subclinical spread of melanoma in situ occurs in 12 to 71 percent of cases. 166 in a study of 674 large melanomas, 166 the visible melanoma plus margins (2–3mm of normal skin) were removed with a debulking excision and sent for formalin- fxed, paraen-embedded, broad loaf sectioning for staging. a Mohs layer was then taken with a 2 to 3mm margin for frozen hematoxylin and eosin (H&e) stain and Mart-1 immunostain. if there were positive margins, additional stages were required. all tumors in this study had margins of at least 5mm. the study was limited by the fact that it was carried out at a single academic center, histological subtypes were not noted, and it did not account for all risk factors (e.g., photoaging degree, percentage of clinically visible tumor after biopsy, tumor color). this study concluded that the subclinical spread of melanoma in situ could be associated with the tumor location (highest risk were tumors on the head, neck, acral sites, and the pretibial leg), recurrence after previous treatment, preoperative size (>1cm), and increasing age (> 60 years, risk increases by about 2% each year). risk increases with multiple risk factors. When clinicians triage surgical treatment of melanoma in situ, it is important to look at risk factors when choosing between standard excision and more exhaustive microscopic margin assessment. 1 66 While invasive melanoma may require more rigorous margin assessment in order to remove subclinical tumor prior to reconstruction, the indications for these techniques have not yet been objectively defined. in a retrospective, cross-sectional analysis of 216 invasive melanoma, MMs with frozen-section, bread-loaf processing of the debulking excision for frozen H&e stain and Mart-1 immunostain was taken. 167 all melanomas had subclinical spreading necessitating at least two stages of MMs to clear margins. for tumors classified t1a, a minimum 5 to 6mm margin was excised, while for t1b and above, a minimum of 1cm was excised. if the biopsy fulfilled the criteria for a sentinel lymph node biopsy, the patient underwent that procedure prior to MMs surgery. in the event that the tumor upstaged during frozen section evaluation of the residual tumor, patients were offered a sentinel lymph node biopsy before reconstruction. after MMs, a debulking excision was sent for paraffin-embedded sectioning to confirm staging and to archive the primary tumor. in this study, 83 out of 216 melanomas had evidence of subclinical spread. the clinical predictors for subclinical spread were tumor location (head and neck were highest risk), recurrence after previous treatment, size more than 1cm, and patient age of 65 or older. one histological predictor was determined, namely the presence of mitoses. thus, it appears that there are

Articles in this issue

Archives of this issue

view archives of Journal of Clinical and Aesthetic Dermatology - Updates on Psoriasis & Cutaneou Oncology