Analysis of Depth of Ablation,Thermal Damage, Wound Healing, and Wound Contraction With Erbium YAG Laser in a Yorkshire Pig Model.

BACKGROUND AND OBJECTIVES: The erbium YAG laser is commonly used for skin resurfacing. It is known that varying the pulse duration can influence residual thermal damage and wound healing. Our study used a porcine model to evaluate a broad range of settings in a comparison of depth of ablation, depth of residual thermal damage (RTD), and wound contraction employing both a full coverage and fractional hand piece with an erbium YAG laser. MATERIALS AND METHODS: The laser delivered an ablative pulse followed by a heating pulse of variable duration using either the full coverage or fractional hand piece. Pulse durations for specific coagulation depths were selected based on existing heat transfer models. The bilateral flanks of a single Yorkshire pig were irradiated. There were 14 treatment groups. 3 sites were treated per group for a total of 42 sites. Two of the 3 sites were for observational assessments and the 3rd site served as a reservoir for biopsies. Biopsy specimens were collected on days 0, 1, 3, 7, 14, and 28. Bleeding, erythema, wound healing, and wound contraction (in the fractional hand piece groups) were assessed. CONCLUSION: Wound healing is faster for fractional laser skin resurfacing compared with traditional contiguous resurfacing as demonstrated by textural changes and degree of erythema. The laser operator can be confident that the depth of ablation displayed on this system accurately reflects what is occurring in vivo for both confluent and fractional modes. Likewise, the measured degree of coagulation was consistent with panel display settings for the confluent mode. However, the degree of coagulation, as measured by the thickness of residual thermal damage, did not vary significantly between the fractional groups. In other words, the pulse duration of the second (heating) pulse did not impact the degree of coagulation in the fractional mode. There was a 2.3% wound contraction between some groups and a 6.5% wound contraction between other groups. A two way analysis of variance found a statistically significant difference in wound contraction based on ablation depth ( P = 0.012) but the degree of coagulation did not prove to be statistically significant for wound contraction (P = 0.66).

Rare case of acral calcified angioleiomyoma with macroscopic calcium extrusion.

Acral calcified angioleiomyoma is an uncommon tumor that presents as a non-descript papule or subcutaneous nodule, classically on the foot. Biopsy or excision is typically the diagnostic method of choice as well as the treatment for these sometimes painful tumors. We report an uncommon clinical presentation of acral calcified angioleiomyoma with considerable extrusion of calcium perforating through the skin.

Synchronous onset of multiple cutaneous neuroendocrine (Merkel cell) carcinomas localized to the scalp.

Merkel cell carcinoma (MCC) is a rare aggressive neoplasm that typically presents as a solitary nodule or plaque on sun-exposed skin of the elderly. Although multiple MCC have been described, they are rare, and metastases must be excluded. We report a case of a 59-year-old white male who presented with abrupt onset of multiple small bluish papules on his frontal scalp. On low power, the tumor had the overall histological silhouette of a nodular basal cell carcinoma. However, because of the lack of an epithelial connection and the cell's cytomorphological features, a MCC was considered and was subsequently confirmed using immunohistochemical stains. The MCC described in this report is unusual in that it presented as multiple cutaneous lesions that arose synchronously, along with micrometastases to sentinel lymph nodes.

Cutaneous squamous cell carcinoma: a comprehensive clinicopathologic classification--part two.

Cutaneous squamous cell carcinoma (SCC) includes many subtypes with widely varying clinical behaviors, ranging from indolent to aggressive tumors with significant metastatic potential. However, the tendency for pathologists and clinicians alike is to refer to all squamoid neoplasms as generic SCC. No definitive, comprehensive clinicopathological system dividing cutaneous SCCs into categories based upon their aggressiveness has yet been promulgated. Therefore, we have proposed the following based upon the malignant potential of SCC variants, separating them into categories of low (< or = 2% metastatic rate), intermediate (3-10%), high (greater than 10%), and indeterminate behavior. Low-risk SCCs include SCC arising in actinic keratosis, HPV-associated SCC, tricholemmal carcinoma, and spindle cell SCC (unassociated with radiation). Intermediate-risk SCCs include adenoid (acantholytic) SCC, intraepidermal epithelioma with invasion, and lymphoepithelioma-like carcinoma of the skin. High-risk subtypes include de novo SCC, SCC arising in association with predisposing factors (radiation, burn scars, and immunosuppression), invasive Bowen's disease, adenosquamous carcinoma, and malignant proliferating pilar tumors. The indeterminate category includes signet ring cell SCC, follicular SCC, papillary SCC, SCC arising in adnexal cysts, squamoid eccrine ductal carcinoma, and clear-cell SCC. Subclassification of SCC into these risk-based categories, along with enumeration of other factors including tumor size, differentiation, depth of invasion, and perineural invasion will provide prognostically relevant information and facilitate the most optimal treatment for patients.

Cutaneous squamous cell carcinoma: a comprehensive clinicopathologic classification. Part one.

Cutaneous squamous cell carcinoma (SCC) includes many subtypes with widely varying clinical behaviors, ranging from indolent to aggressive tumors with significant metastatic potential. However, the tendency for pathologists and clinicians alike is to refer to all squamoid neoplasms as generic SCC. No definitive, comprehensive clinicopathological system dividing cutaneous SCCs into categories based upon their aggressiveness has yet been promulgated. Therefore, we have proposed the following based upon the malignant potential of SCC variants, separating them into categories of low (< or = 2% metastatic rate), intermediate (3-10%), high (greater than 10%), and indeterminate behavior. Low-risk SCCs include SCC arising in actinic keratosis, HPV-associated SCC, tricholemmal carcinoma, and spindle cell SCC (unassociated with radiation). Intermediate-risk SCCs include adenoid (acantholytic) SCC, intraepidermal epithelioma with invasion, and lymphoepithelioma-like carcinoma of the skin. High-risk subtypes include de novo SCC, SCC arising in association with predisposing factors (radiation, burn scars, and immunosuppression), invasive Bowen's disease, adenosquamous carcinoma, and malignant proliferating pilar tumors. The indeterminate category includes signet ring cell SCC, follicular SCC, papillary SCC, SCC arising in adnexal cysts, squamoid eccrine ductal carcinoma, and clear-cell SCC. Subclassification of SCC into these risk-based categories, along with enumeration of other factors including tumor size, differentiation, depth of invasion, and perineural invasion will provide prognostically relevant information and facilitate the most optimal treatment for patients.

Metaplastic breast carcinoma histologically mimicking cutaneous spindle cell squamous cell carcinoma.

Squamous cell carcinoma is one of the most common primary cutaneous carcinomas but on rare occasion, metastatic squamous cell carcinoma from a distant site or solid organ can present as a cutaneous lesion. Most metastases occur as dermal nodules or involve the dermal lymphatics, but when they are intimately associated with the epidermis, distinguishing the lesion as primary or metastatic may be extremely difficult and usually requires a clinical history or high index of suspicion. A 71-year-old woman presented with multiple eruptive nodules over her chest, flank, and back. Histologically the lesions appeared to be arising from the surface epithelium and consisted of atypical, predominantly spindle cells, some of which streamed off of the epidermis. Following the initial evaluation, a history of breast carcinoma with subsequent radiation therapy and ultimate mastectomy was obtained, and the original breast biopsy and mastectomy material was reviewed. After performing additional studies, it became clear that the origin of the carcinomas was metastatic from an underlying metaplastic breast carcinoma.

Adventitial cystic disease of the axillary artery.

Adventitial cystic disease (ACD) is an extremely rare cause of arterial and venous insufficiency, with only 317 reported cases in the world literature. These lesions have been previously described in the popliteal fossa, external iliac artery, and distal brachial, radial, and ulnar arteries as well as in the proximal saphenous vein at the ankle. We describe here the first reported case of this disease in a proximal vessel, the axillary artery. A 33-year-old man was evaluated for upper extremity arterial insufficiency and was diagnosed with ACD on the basis of physical examination and radiographic findings, which was confirmed by pathological assessment. The patient was treated by excision of the lesion and interposition vein bypass. As this represents the first case of ACD in the proximal vasculature, it demonstrates that these lesions can occur in axial blood vessels.