Publications by authors named "Thomas Knackstedt"

Background: Prognostication of atypical spindle cell neoplasms, including atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS), is challenging; outcomes vary widely, and further identification of prognostic features is crucial.

Objective: To evaluate prognostic factors that may portend worse outcomes in patients with AFX and PDS.

Materials And Methods: A retrospective chart review of patients with AFX and PDS was conducted.

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Background: Immunohistochemical (IHC) staining can be used alongside Mohs micrographic surgery to aid in margin assessment of subtle tumors, yet existing estimates of IHC utilization have primarily relied on survey or older data that lacks stratification.

Objective: To characterize national IHC utilization trends by Mohs surgeons, stratifying by surgeon characteristics and modeling future adoption.

Methods: Longitudinal analysis of 2014 to 2021 Medicare Public Use Files.

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Background: Amid a movement toward value-based healthcare, increasing emphasis has been placed on outcomes and cost of medical services. To define and demonstrate the quality of services provided by Mohs surgeons, it is important to identify and understand the key aspects of Mohs micrographic surgery (MMS) that contribute to excellence in patient care.

Objective: The purpose of this study is to develop and identify a comprehensive list of metrics in an initial effort to define excellence in MMS.

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Background: Incidence and treatment disparities for cutaneous melanomas have been documented among racial and sociodemographic minorities. However, the association between treatment types, race, and socioeconomic status remains unknown.

Objective: To characterize treatment differences for head and neck melanoma in situ (MIS) and lentigo maligna (LM) based on race and sociodemographic variables.

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Background: The lips are a common location for skin cancer, and thus, a common site for Mohs micrographic surgery (MMS). As an important cosmetic and functional facial unit, MMS defects and reconstruction can affect patient perception on functional and aesthetic outcomes.

Objective: The objective of this study was to compare aesthetic and functional outcomes after upper lip MMS between patients with vermillion sparing repairs (VSR) versus vermillion crossing repairs (VCR).

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Background: Malignant peripheral nerve sheath tumors (MPNSTs) are clinically aggressive soft tissue sarcomas that can present as cutaneous or subcutaneous based tumors that are commonly associated with neurofibromatosis type 1. Historically, these tumors have poor outcomes. Previously, no study has compared survival of cutaneous versus subcutaneous MPNSTs.

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Background: Primary melanoma management relies on tumor extirpation and staging sentinel lymph node biopsy (SLNB) in eligible patients. This study compares SLNB utilization in patients undergoing wide local excision (WLE) or Mohs micrographic surgery (MMS).

Methods: American Joint Committee on Cancer seventh edition ≥ patients with T1b melanoma undergoing WLE or MMS in the Surveillance, Epidemiology, and End Results program were included.

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Background: Perineural invasion (PNI) is considered a high-risk histopathologic feature in many skin cancers. Perineural invasion is a well-known poor prognostic factor of squamous cell carcinoma, but is poorly understood in the context of basal cell carcinoma (BCC).

Objective: To analyze available demographic, clinical, and treatment data for BCC with PNI and the effect of these variables on recurrence patterns, disease progression, and cancer-specific mortality (CSM).

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Within organized dermatology, it is imperative that leaders embody a diverse group of individuals, reflective of the dermatologists they represent and the greater U.S. population.

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Background: Bone invasion has long been recognized as a poor prognostic indicator for cutaneous squamous cell carcinoma (SCC). Survival analyses of factors associated with SCC with bone invasion have not been published.

Objective: To analyze all published demographic, clinical, and treatment data for SCC with bone invasion and assess the impact of prognostic variables on disease progression, disease-specific death, and overall mortality.

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Background: The effect of treatment delays on melanoma outcomes remains unclear.

Objective: To assess the impact of surgical treatment delays on melanoma-specific mortality (MSM) and overall mortality (OM).

Methods: Patients with stage I to III cutaneous melanoma were identified through the Surveillance, Epidemiology, and End Results database (N = 108,689).

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Large defects after Mohs micrographic surgery present a reconstructive challenge. The keystone design perforator island flap has proven to be simple and effective in the repair of large skin defects after cancer removal. We present a case of such a defect on the upper arm that was successfully reconstructed with the keystone flap.

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Background: While bilobed and trilobed transposition flaps are established workhorses for nasal reconstruction, their utility is often limited to defects less than 1.5 cm, subjecting patients to more involved multistage or cosmetically less favorable repairs. We highlight the use of bilobed and trilobed transposition flaps for intermediate (≥ 1.

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Surgical defects involving multiple facial cosmetic subunits can be challenging to reconstruct. We report on a patient with a complex temporal defect following Mohs micrographic surgery (MMS) for a basal cell carcinoma (BCC). The extension of the defect across the left temple, cheek, and forehead hindered the utilization of linear closures or flaps.

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The objective is to determine the cost-effectiveness of sentinel lymph node biopsy (SLNB) for cutaneous squamous cell carcinoma (CSCC) according to the Brigham and Women's Hospital (BWH) Tumor Staging system. A decision analysis was utilized to examine costs and outcomes associated with the use of SLNB in patients with high-risk head and neck CSCC. Decision tree outcome probabilities were obtained from published literature.

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Nail unit squamous cell carcinoma and melanoma are the most common malignancies of the nail apparatus. Compared to their cutaneous counterparts, they are diagnosed later and perceived as more aggressive. This may result in overzealous management, including radiographic imaging with poor sensitivity and specificity, interventional nodal staging by sentinel lymph node biopsy, amputation over digit-sparing tumor resections, and elaborate reconstructions after tumor extirpation.

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Melanoma detection, prognosis, and treatment represent challenging and complex areas of cutaneous oncology with considerable impact on patient outcomes and healthcare economics. Artificial intelligence (AI) applications in these tasks are rapidly developing. Neural networks with increasing levels of sophistication are being implemented in clinical image, dermoscopic image, and histopathologic specimen classification of pigmented lesions.

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