On the diagnosis and treatment of intraepidermal carcinoma

Abstract: Intraepidermal carcinoma (IEC), also known as Bowen disease (BD) or squamous cell carcinoma (SCC) in situ, is a precursor to SCC. The incidence of IEC is increasing rapidly in fair-skinned populations with a subsequent increase in patient morbidity. This calls for optimized patient management through improving diagnosis and choosing the most advantageous treatment. A key step is making a correct diagnosis, which is best accomplished using dermoscopy prior to histopathological confirmation. Several treatment options are available for IEC, e.g. photodynamic therapy (PDT), surgical excision and destructive methods like cryosurgery and curettage. The purpose of this thesis was to evaluate the agreement between dermatologists on the dermoscopic findings of IEC as well as the effectiveness of PDT, surgical excisions and a comparison between cryosurgery and curettage. In Paper I, we measured the interobserver agreement between international dermatologists on dermoscopic findings in IEC. The frequency of pre-defined dermoscopic findings were: scales (83%), dotted/glomerular vessels (77%), pinkish-white areas (73%), and hemorrhage (46%). The interobserver agreement ranged from poor to moderate with the highest Kappa values noted for scales (0.55) and hemorrhage (0.54), while pinkish- white areas showed the lowest Kappa value (0.015). In Paper II, we assessed the effectiveness, recurrence risk, and factors affecting the response rate of PDT for IEC. PDT is a relatively effective treatment modality with an overall clearance rate of 63.4%. Larger lesions (>20 mm) and a single PDT session were risk factors for unsuccessful treatment. In Paper III, we aimed to evaluate the clinicopathological risk factors for incomplete excision of IEC. Less surgical experience was independently associated with incomplete surgical excisions using a less strict definition (mild to moderate dysplasia at the resection margin), whereas less experience and location on the head and neck area or upper extremities was independently associated with incomplete excision using a strict definition (no dysplasia at the resection margin). In Paper IV, we performed a randomized controlled trial to compare the effectiveness of cryosurgery and curettage for IEC. The overall clearance rate 1 year after cryosurgery was significantly higher than with curettage (94.6% vs 78.9%). Nevertheless, wound healing times were significantly shorter with curettage. In conclusion, the interobserver agreement for dermoscopic findings of IEC is poor to moderate. PDT provides clearance in approximately two-thirds of the treated IECs. Risk factors for incomplete excisions of IEC are less experienced surgeons and location on the head and neck area or upper extremities. Cryosurgery and curettage both show high clearance rates, with cryosurgery being significantly more effective and wound healing times being shorter with curettage

Clinical and dermoscopic diagnosis of actinic keratosis

Actinic keratosis (AK) is one of the most frequent tumors of the skin; the diagnosis is basically clinical although in some cases it may be difficult to distinguish it from other keratinocytic or even melanocytic neoplasms when it presents in pigmented form. Over the years several clinical classifications and scores to objectify the burden of disease have been created. In this review the most frequent scores and classification systems are summarized along with dermoscopic criteria that allow diagnosis with greater sensitivity and specificity

Aspects of skin cancer diagnosis in clinical practice

Skin cancer incidence is increasing in fair-skinned populations. The three most common skin cancers are basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). A correct diagnosis is crucial for an efficient and tailored treatment for the skin cancer patient. The purpose of this thesis was to evaluate different aspects of the preoperative diagnosis of skin cancer. The studies making up this thesis were based on analysis of data from a register including all skin tumour excisions at the Department of Dermatology in Helsingborg, Sweden, from March 2008 to January 2015. The registered data included e.g. sex and age of the patient, tumour site and size, dermoscopic features of the tumour, the preliminary preoperative and final postoperative (histopathological) diagnosis as well as tumour cells at surgical margins. The preliminary preoperative clinical diagnosis was compared with the final histopathological diagnosis in 2,953 excised tumours, whereof 1,626 (55.1%) were malignant, showing high diagnostic accuracy for the diagnosis of malignant tumour and for the diagnosis of basal cell carcinoma (BCC). A total of 96.0% of all excisions had tumour-free margins. The number needed to excise (NNE) for melanoma (the number of pigmented lesions excised to find one melanoma) was calculated for 1,717 cases of excised skin tumours (252 melanomas, 1,395 naevi and 70 seborrhoeic keratoses (SK)). The overall NNE value during the study period was 6.5 (SKs not included). When SKs were included in the calculations the NNE was 6.8. The NNE value decreased with increasing age of the patient and varied for different body locations, with the highest values found for the trunk and the lowest for the arms. When the ABCD rule of dermoscopy was used preoperatively at the bedside in 309 cases (46 melanomas and 263 naevi), use of the algorithm achieved 83% sensitivity and 45% specificity for melanoma diagnosis. A sensitivity of 74% and specificity of 91% were seen for the clinical diagnosis. A considerable percentage (19.6%) of very early melanomas were preoperatively not expected to be melanomas by the dermatologist. The prediction of histopathological subtype of BCC is important for choosing optimal treatment in BCC patients and was assessed in 1,501 cases with pre- or postoperative diagnosis of BCC. The prediction of superficial BCC (sBCC) significantly improved after an educational update on dermoscopic criteria for sBCC in cases assessed by dermoscopy. In conclusion, these studies have shown high accuracy of the preoperative diagnosis of malignant tumour and BCC. With increasing age of the patient, a higher rate of excised pigmented skin lesions was melanomas. Bedside use of the ABCD rule of dermoscopy achieved high sensitivity but low specificity for melanoma diagnosis; however, clinical information seemed to add to specificity. Prediction of sBCC was enhanced after a dermoscopy training session and when dermoscopy was mandatory

New Options for Non-invasive Imaging and Non-invasive Treatment of Skin Cancers

Tausta Tyvisolusyöpä on maailman yleisin syöpä. Tyvisolusyövällä on eri alatyyppejä, joista pinnallinen tyvisolusyöpä ja ohut nodulaarinen tyvisolusyöpä ovat vähäisen riskin tyyppejä, jotka on mahdollista hoitaa muutoin kuin leikkaamalla. Pinnallinen tyvisolusyöpä on lisääntynyt muita alatyyppejä nopeammin, ja näin ollen myös ei-kirurgisten hoitovaihtoehtojen käyttö todennäköisesti lisääntyy. Valoaktivaatiohoito ja voidehoidot, joita ovat imikimodi ja 5-fluorourasiili, ovat vaihtoehtoja kirurgialle. Valoaktivaatiohoidon etuja ovat erinomainen kosmeettinen lopputulos sekä lyhytkestoisempi hoitoaika ja paikallisreaktion kesto verrattuna voidehoitoihin. Imikimodin teho on kuitenkin parempi kuin valoaktivaatiohoidon. Suuren riskin tyvisolusyöpiä ovat aggressiiviset alatyypit, joille tyypillisiä ovat kasvaimen epätarkkarajaisuus ja kliinisesti näkymättömät kasvainalueet. Lentigo maligna -melanooma on ihomelanooman alamuoto, jolle tyypillisiä ovat myös nämä piirteet. Lentigo maligna on lentigo maligna -melanooman esiastemuoto. Näitä kahta on vaikea erottaa toisistaan silmin ja dermatoskoopilla arvioiden. Epätarkkarajaiset ihosyövät ovat siis kliininen haaste. Kajoamattomilla kuvantamismenetelmillä on mahdollista parantaa ihokasvainten diagnostiikkaa ja arviota. Hyperspektrikuvantaminen on uusi, nopea ja tietokoneavusteinen kuvantamismenetelmä, jolla on laaja kuvausalue. Tavoitteet Väitöskirjassa tutkitaan hyperspektrikuvantamista ja vähäisen riskin tyvisolusyövän valoaktivaatiohoitoa kliinisessä lääketutkimuksessa. Tavoitteena on tutkia hyperspektrikameran kykyä erottaa lentigo maligna -melanooma ja lentigo maligna toisistaan, sekä arvioida hyperspektrikameran kykyä määrittää epätarkkarajaisen tyvisolusyövän rajat ennen leikkausta verrattuna kliiniseen arvioon dermatoskoopin kanssa. Kliinisen lääketutkimuksen tavoitteena on verrata kolmen eri valoherkistäjävoiteen tehoa vähäisen riskin tyvisolusyövän valoaktivaatiohoidossa. Menetelmät Hyperspektrikuvantamista tutkittiin kahdessa pilottitutkimuksessa. Näistä toisessa kuvattiin lentigo malignaa/lentigo maligna –melanoomaa, ja toisessa epätarkkarajaista tyvisolusyöpää. Molemmissa tutkimuksissa kasvaimet arvioitiin ennen kuvantamista kliinisesti dermatoskoopin avulla. Lopuksi kasvaimet leikattiin. Hyperspektrikuvat tuotettiin matemaattisen mallinnuksen avulla tietokoneavusteisesti. Patologi, joka arvioi leikkeet, ei tiennyt, mitä hyperspektrilöydökset olivat. Kameran löydöksiä verrattiin histopatologiaan, ja epätarkkarajaisen tyvisolusyövän tapauksessa myös kliinisesti määritettyihin kasvaimen rajoihin. Kliininen lääketutkimus oli tutkijalähtöinen, prospektiivinen, kontrolloitu, satunnaistettu ja kaksoissokkoutettu. Tutkimuksessa verrattiin kahden uudehkon valoherkistäjävoiteen eli 5-aminolevuliinihapon nanoemulsion ja matalapitoisen heksyyliaminolevulinaatin tehoa laajasti käytettyyn metyyliaminolevulinaattiin. Päätulos oli histologinen paraneminen kolme kuukautta valoaktivaatiohoidon jälkeen. Toissijaisia tuloksia olivat kosmeettinen lopputulos sekä hoidon haittavaikutukset eli kipu ja hoidonjälkeinen paikallisreaktio. Kivunhoitona käytettiin pitkävaikutteista paikallispuudutetta ennen kasvainten käsittelyä valoaktivaatiohoitoa varten. Tutkimuksessa arvioitiin myös valoherkistäjävoiteen fluoresenssia ja kulumista valotuksen aikana (ns. photobleaching) kokeellisella laitteistolla. Diagnoosi ja hoitotulos varmistettiin koepaloin. Tutkimuksessa potilaat ja tulosten arvioijat eivät tienneet, mitä valoherkistäjää oli käytetty. Tulokset Lentigo maligna -melanooman, lentigo malignan ja terveen ihon hyperspektrikäyrät ovat erilaisia. Näin ollen lentigo maligna -melanooma ja lentigo maligna on mahdollista erottaa toisistaan hyperspektrikuvantamisen avulla. Hyperspektrikuvien perusteella oli myös mahdollista paikallistaa invaasioalue. Hyperspektrikamera määritti epätarkkarajaisen tyvisolusyövän rajat tarkemmin kuin kliinisesti oli määritetty, ja histopatologia tuki tätä löydöstä. Valoaktivaatiohoidossa tyvisolusyöpä parani lähes yhtä hyvin matalapitoisella heksyyliaminolevulinaatilla kuin korkeapitoisemmilla 5-aminolevuliinihapon nanoemulsiolla ja metyyliaminolevulinaatilla. Valoherkistäjävoiteiden välillä ei ollut eroja haittavaikutuksissa tai kosmeettisessa lopputuloksessa. Fluoresenssin ja valoherkistäjän kulumisen tuloksissa oli laaja hajonta. Johtopäätökset Hyperspektrikuvantaminen vaikuttaa lupaavalta uudelta menetelmältä, jolla on laaja kuvausalue, ja joka on nopea ja helppokäyttöinen. Lisäksi hyperspektrikamera näyttää pystyvän visualisoimaan silmälle näkymättömiä muutoksia. Heksyyliaminolevulinaatti on mielenkiintoinen uusi vaihtoehto vähäisen riskin tyvisolusyövän valoaktivaatiohoitoon, sillä jo matalalla pitoisuudella saavutetaan vastaava hoitotulos kuin korkeammilla pitoisuuksilla 5- aminolevuliinihapon nanoemulsiota tai metyyliaminolevulinaattia. Kuitenkaan hoidon kosmeettisessa lopputuloksessa tai haittavaikutuksissa ei ole eroja valoherkistäjien välillä.Background Basal cell carcinoma is the most common cancer in the world. The incidence of superficial basal cell carcinoma, a subtype of basal cell carcinoma, is rising at a far steeper rate than the other subtypes, and as a non-aggressive subtype, it can be treated non-invasively. Aggressive subtypes of basal cell carcinoma are often ill-defined, which poses a clinical problem in preoperative margin assessment. Another ill-defined skin cancer type is lentigo maligna. Lentigo maligna is an in situ melanoma, and a precursor of lentigo maligna melanoma. These two forms are clinically challenging to distinguish from each other, which is crucial as melanoma has the worst prognosis of all skin cancers. Non-invasive imaging is an option for increasing the accuracy of preoperative diagnosis and the assessment. Hyperspectral imaging is a novel, fast, and computer-aided imaging modality with a wide field of view. In non-invasive treatment of non-aggressive basal cell carcinomas, photodynamic therapy has many advantages: an excellent cosmetic outcome as well as a shorter application time and recovery period. Notwithstanding these advantages, the efficacy of photodynamic therapy is lower when compared to topical pharmacological options such as imiquimod and 5- fluorouracil. Objectives This dissertation focuses on non-invasive imaging and non-invasive treatment. In non-invasive imaging, the aim is to study the performance of a hyperspectral imaging system in separating lentigo maligna melanoma from lentigo maligna and assessing the preoperative margins of ill-defined basal cell carcinomas compared to clinical delineation assessments performed with a dermoscope. In non-invasive treatment, the aim is to compare the efficacy of three different photosensitisers in photodynamic therapy of non-aggressive basal cell carcinomas. Methods There are two pilot studies with hyperspectral imaging: one on lentigo maligna and lentigo maligna melanoma, and another one on ill-defined basal cell carcinoma. Tumours were preoperatively visually inspected utilising a dermoscope, and thereafter imaged with the hyperspectral imaging system. Next, surgical excision was performed. Hyperspectral images were created with computer-aided mathematical models. Additional mathematical models were subsequently developed. In the results analysis, the findings of the hyperspectral imaging and clinically assessed margins were compared to the histopathology results, where assessment was performed blind to the hyperspectral imaging findings. A non-sponsored, prospective, randomised, controlled and double-blinded trial focused on non-invasive treatment. In this trial, two novel photosensitisers, 5- aminolevulinic acid nanoemulsion and low-concentration hexylaminolevulinate, were compared to the commonly used methylaminolevulinate in photodynamic therapy of non-aggressive basal cell carcinomas, i.e. thin nodular or superficial subtypes. The primary outcome was histological clearance at three months. Secondary outcomes included adverse events such as pain associated with the treatment while using a long-lasting local anaesthetic as pain management, post- treatment reaction, as well as cosmetic outcome, and fluorescence and photobleaching during the illumination. We used an experimental fluorescence imaging system. Punch biopsies were performed prior to treatment and during follow-up. Both patient and observers of outcomes were blind to the photosensitiser that was used. Results Hyperspectral imaging exhibited a unique hyperspectral graph for lentigo maligna melanoma, lentigo maligna, and healthy skin. Based on these results, hyperspectral images were created where hyperspectral data was represented in several abundance maps. The maps showed differing abundances for lentigo maligna melanoma and lentigo maligna, and it was possible to localise the invasion site inside the lesion. For ill-defined basal cell carcinoma, the margins of the tumour were delineated more accurately than by clinical assessment, and the results were confirmed with histopathology. The results of the clinical trial in photodynamic therapy showed that the histological clearance of hexylaminolevulinate was similar compared to 5- aminolevulinic acid nanoemulsion and methylaminolevulinate, with no differences in cosmetic outcome, pain or post-treatment reaction between the arms. In our fluorescence and photobleaching analyses the results were widely spread. Conclusions In conclusion, hyperspectral imaging seems to be a promising and useful new imaging modality with a wide field of view: it is fast, easy to use and it seems to be capable of visualising subclinical findings. In non-invasive treatment, hexylaminolevulinate is an interesting option for photodynamic therapy of non- aggressive basal cell carcinomas. Hexylaminolevulinate at low concentrations achieves a comparable efficacy to 5-aminolevulinic acid nanoemulsion and methylaminolevulinate at higher concentrations. No differences were observed in adverse events or cosmetic outcome between the arms

Clinical and Dermoscopic Diagnosis of Actinic Keratosis

Actinic keratosis (AK) is one of the most frequent tumors of the skin; the diagnosis is basically clinical although in some cases it may be difficult to distinguish it from other keratinocytic or even melanocytic neoplasms when it presents in pigmented form. Over the years several clinical classifications and scores to objectify the burden of disease have been created. In this review the most frequent scores and classification systems are summarized along with dermoscopic criteria that allow diagnosis with greater sensitivity and specificity.  

Dermatoscopy

This book is a collection of chapters on dermatoscopy, which is a fast, easy-to-learn, low-cost, and non-invasive diagnostic method utilizing the Rayleigh scattering phenomenon to visualize epidermal and subepidermal structures. Dermatoscopy has become increasingly popular for allowing visualization of structures that are impossible to see with the naked eye. Its use provides insight into the biological potential of skin lesions, enabling efficient management and follow-up. The book focuses on the features of some of the most common skin neoplasms, such as combined nevi, as well as those that are more challenging to assess, such as pigmented lesions of the eyelid margins. It also provides novel insights into the role of dermatoscopy in palmoplantar dermatoses and discusses precautions in dermatoscopy during the SARS-CoV2 pandemic

Microscopía confocal de reflectancia in vivo en dermatología: Aplicación en el diagnóstico de tumores cutáneos.

[spa] La microscopía confocal de reflectancia in vivo (MCR) es una técnica no invasiva que permite obtener un diagnóstico de forma inmediata y en tiempo real de patología cutánea tumoral con una precisión diagnóstica que se acerca al diagnóstico histológico convencional. La MCR puede permitir un seguimiento clínico de respuesta a tratamientos no invasivos de patología tumoral, como la terapia fotodinámica, sin necesidad de realizar biopsias. El presente trabajo reúne cuatro estudios realizados con el fin de demostrar la utilidad de la técnica de MCR en el estudio y manejo clínico de las neoplasias cutáneas. En el primer estudio se incluyeron de forma prospectiva 154 tumores cutáneos para establecer qué parámetros de microscopía confocal se relacionaban con cada tumor, analizar si estos criterios eran reproducibles y finalmente evaluar la correlación de estos parámetros con la dermatoscopia y la histología convencional. Según los resultados de este primer trabajo, cuatro características observables mediante MCR permitían diferenciar las lesiones melanocíticas (LM) de las no melanocíticas (LNM): patrón epidérmico en empedrado, crecimiento pagetoide, presencia de nidos celulares en la dermis y presencia de papilas dérmicas bien definidas en toda la lesión. Dentro de las LM, la presencia de células redondas en estratos suprabasales y de células nucleadas atípicas en la dermis se asociaban al diagnóstico de melanoma; mientras la presencia de papilas dérmicas con contorno reflectante (anillos basales) así como la observación de células basales típicas, se asociaban a nevus. Basándonos en la reproducibilidad y correlación histológica y dermatoscópica de los criterios de MCR, se desarrolló un algoritmo en dos etapas para el diagnóstico de melanoma consiguiendo una sensibilidad del 86,1% y una especificidad del 95.3% (J Am Acad Dermatol. 2009;61:216-29). En el segundo trabajo, se estudiaron los parámetros de microscopía confocal en melanomas de extensión superficial (MES) en fase de crecimiento vertical y en melanomas nodulares (MNs). Para ello se incluyeron de forma prospectiva 10 MNs, 10 MES con área nodular y 10 MES con área palpable. Se realizó un análisis sistemático y estudio estadístico de las características dermatoscópicas, confocales e histológicas de los 3 grupos de lesiones. Mientras los MNs mostraban patrones de dermatoscopia inespecíficos, los MES exhibían patrones multicomponente y puntuaciones más altas en los algoritmos de dermatoscopia. Por MCR, los MNs tenían poco crecimiento pagetoide y presentan a menudo un patrón normal de la epidermis, a diferencia de los MES que se caracterizaban por un patrón desestructurado de la epidermis y la presencia de abundantes células en estratos suprabasales Tanto en los MNs como en las áreas nodulares de los MES, en la unión dermo-epidérmica no se visualizaban las papilas dérmicas, en su lugar se observa una proliferación de células reflectantes atípicas no agregadas. En la dermis, los MNs exhibían a menudo unos agregados celulares característicos de aspecto cerebriforme, que podían observarse también en las áreas nodulares de algunos MES (Arch Dermatol. 2008;144:1311-20). En un tercer artículo estudiamos las características del carcinoma basocelular pigmentado (CBC) mediante MCR, histología e inmunohistoquímica (S-100, MelanA, HMB-45 y CD1a).Mediante MCR demostramos la presencia de estructuras reflectantes muy características de aspecto dendrítico dentro de los nidos tumorales situados en la dermis de los CBC estudiados, que correspondían por estudio inmunohistoquímico a melanocitos no neoplásicos que poblaban los nidos (Arch Dermatol. 2007;143:883-6). Finalmente, en un cuarto trabajo estudiamos la aplicabilidad de la MCR en el diagnóstico y seguimiento de pacientes con genodermatosis de alto riesgo de desarrollar cáncer cutáneo (síndrome de Gorlin -SG- y Xeroderma pigmentoso -XP-) afectos de CBCs múltiples y tratados con terapia fotodinámica con metil-aminolevulinato (MAL). Se incluyeron 4 pacientes con SG y 2 hermanos con XP. Se trataron lesiones únicas o múltiples en zonas localizadas con 1 a 3 ciclos de TFD-MAL. La exploración con MCR se realizó antes y 3 meses después del tratamiento en las lesiones diana. Se trataron 13 CBCs pigmentados faciales en los pacientes afectos de XP y múltiples lesiones en cara o tronco (hasta 200) en los afectos de SG. Globalmente se obtuvo una remisión clínica completa en un 25- 67% de las lesiones. La respuesta al tratamiento puedo ser correctamente evaluada mediante MCR (J Eur Acad Dermatol Venereol. 2011;25:819-27). En conclusión, la MCR parece ser útil en el diagnóstico diferencial de las lesiones pigmentadas y complementa a la dermatoscopia en el diagnóstico del melanoma. Esta técnica permite caracterizar subtipos de melanoma como el melanoma nodular. También sirve de ayuda en el diagnóstico y caracterización del carcinoma basocelular pigmentado y en su monitorización tras tratamiento con terapias no invasivas como la terapia fotodinámica.[eng] This work brings together four studies to demonstrate the clinical utility of reflectance confocal microscopy (RCM) in the clinical management of cutaneous neoplasms. In the first study we prospectively included 154 skin tumors in order to develop an algorithm for the in vivo diagnosis of skin tumors. We analyzed RCM features on stored images before excision and performed statistical analyses to determine the association of RCM features with tumor types. Four confocal features differentiated melanocytic lesions (ML) from non-melanocytic lesions (NML): cobblestone pattern of epidermal layers, pagetoid spread, mesh appearance of the dermoepidermal junction, and the presence of dermal nests. Within ML, the presence of roundish suprabasal cells and atypical nucleated cells in the dermis was associated with melanoma, and the presence of edged papillae and typical basal cells was associated with nevi. Based on the reproducibility and histological and dermoscopic correlation of MCR criteria, we developed a two-step algorithm for the diagnosis of melanoma, achieving a sensitivity of 86.1% and specificity of 95.3% (J Am Acad Dermatol. 2009; 61: 216-29). In the second work we characterized nodular melanoma (NM) by dermoscopy, RCM and histopathology. We included 10NMs, 10 superficial spreading melanomas (SSMs) with a nodular area, and 10 SSMs with a blue palpable area but not yet nodular. Whereas NMs had predominantly nonspecific global dermoscopic patterns, SSMs exhibited a multicomponent pattern and higher dermoscopic scores. By RCM, distinctive confocal features were observed at all cutaneous levels in NMs compared with SSMs, suggesting different biological behavior. (Arch Dermatol. 2008, 144:1311-20). In the third article we explored the confocal features of pigmented basal cell carcinoma (BCC) and correlated the findings with histology and immunohistochemistry. RCM revealed highly refractive dendritic structures within tumor nests that corresponded to the presence of melanocytes within the tumor. RCM allowed the study of pigmented BCC and the identification of specific criteria. (Arch Dermatol. 2007; 143:883-6). Finally, in the fourth paper we aimed to evaluate the efficacy of methyl-aminolevulinate (MAL) photodynamic therapy (PDT) in basal cell carcinomas (BCCs) from patients with Gorlin syndrome (GS) and Xeroderma pigmentosum (XP), and to determine the utility of RCM in the diagnosis and the evaluation of therapeutic response. We included 4 patients with GS and 2 siblings with XP. Single or multiple lesions in localized areas were treated with 1 to 3 cycles of MAL PDT. RCM was performed before and 3 months after the treatment in target lesions. Overall, we obtained a complete clinical remission in 25 to 67% of the lesions. RCM could identify confocal features for BCC and assess tumor remissions after treatment (J Eur Acad Dermatol Venereol. 2011; 25:819-27)