Stage III Melanoma: A Proposed Staging Model That Outperforms the American Joint Committee on Cancer Eighth Edition Staging System.

National Comprehensive Cancer Network guidelines state that clinical stage III melanoma patients may undergo ultrasound surveillance of the nodal basin in lieu of complete lymph node dissection (CLND). This has led to an inability to accurately classify patients according to the American Joint Committee on Cancer (AJCC) eighth edition staging system because it uses the total number of positive lymph nodes from the CLND to assign a pathologic N stage. We propose a new model for clinical stage III melanoma patients that does not rely on the total number of positive lymph nodes. Instead, it uses Breslow depth, ulceration status, sentinel lymph node metastasis size, and extracapsular extension to stratify patients into groups 1 to 4. We compared our model's ability to predict melanoma-specific survival (MSS), distant metastasis-free survival (DMFS) and locoregional recurrence, and distant metastasis-free survival (DMFS-LRFS) to the current AJCC system with and without CLND-data using a Cox proportional hazards model and Akaike Information Criteria weights. Although not reaching our predetermined level of statistical significance of 95%, our model was 5 times more likely to better predict MSS compared with the AJCC model with CLND. In addition, our model was significantly better than the AJCC model without CLND in predicting MSS. Our model performed significantly better than the AJCC model in predicting DMFS and DMFS-LRFS regardless of whether data from CLND were included.

Application of immunohistochemical studies in diagnosing emerging superficial mesenchymal neoplasms.

Molecular diagnostics, with the subsequent development of novel immunohistochemical markers, continues to advance and expand the field of soft tissue pathology. As such, the ever-evolving molecular diagnostic landscape will continue to shape and refine our understanding and classification of neoplasms. This article reviews the current literature on various tumors of mesenchymal origin, including fibroblastic/fibrohistiocytic, adipocytic, vascular, and tumors of uncertain origin. We aim to give the reader a detailed understanding and pragmatic approach to various new and established immunohistochemical stains in diagnosing these neoplasms and also discuss various pitfalls with significant repercussions.

Cutaneous inflammatory myofibroblastic tumor with CARS-ALK fusion: Case report and literature review.

Cutaneous inflammatory myofibroblastic tumors (IMT) constitute a rare entity, generating a diagnostic pitfall when diagnosing spindle cell proliferation within the dermis. Raising awareness of this tumor among dermatopathologists remains vital in differentiating it from common cutaneous tumors such as fibrous histiocytoma, atypical fibroxanthoma, melanoma, poorly differentiated carcinoma, and other more aggressive tumors. Accurate diagnosis of IMT aids in ensuring appropriate management and follow-up for patients while preventing unnecessary harm and overtreatment. Here we report a case of a 38-year-old female with a painless, slow-growing nodule of the left posterior scalp initially diagnosed as a dermatofibroma. The histopathological examination revealed an ill-defined dermal nodule of spindled cells without connection or infiltration of the epidermis. At high power, the cells were arranged in fascicles with a prominent background of lymphocytic infiltrate. Immunohistochemical analysis showed strong diffuse immunoreactivity for anaplastic lymphoma kinase (ALK), and targeted RNA sequencing identified a CARS-ALK fusion ultimately confirming the accurate diagnosis of a cutaneous IMT.

Five New Cases of Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome (MMIHS), with One Case Showing a Novel Mutation.

BACKGROUND: Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a lethal congenital disorder characterized by a large, non-obstructed bladder, microcolon, and lack of proper peristalsis. MATERIALS AND METHODS: Five cases of MMIHS were identified, confirmed histologically and were predominantly female (F:M, 4:1). DNA sequencing was also performed. RESULTS: Four cases showed mutations in the α3 and ß4 nicotinic acetylcholine receptor (ηAChR) subunits (CHRNA3 and CHRNB4, respectively) on chromosome 15q24. The 5th case had a delayed clinical presentation of intussusception at 11 months and showed a novel missense mutation in ATP2B4 on Chromosome 1q32. CONCLUSION: The first four patients showed a previously identified mutation. The 5th patient shows a novel mutation in ATP2B4. This novel gene was associated with a less severe presentation and increases success of multiorgan transplant than the other four patients. This highlights how identifying various mutations may impact prognosis and clinical treatment plans for MMIHS patients.

Cutaneous Vascular Neoplasms of Uncertain Biological Behavior.

Neoplasms of uncertain biological behavior present physicians with a genuine conundrum in practice. Cutaneous vascular neoplasms within this category are exceedingly rare, possessing significant gaps and uncertainty in many facets of clinical practice. Firstly, lesions were selected for review based on their categorization as indeterminate behavior, indicating the potential for local recurrence and rarely metastasize. After identification of the target lesions, a comprehensive review of the literature using national databases produced several landmark studies and case series regarding these neoplasms. Limiting the review to only cutaneous limited tumors narrowed the pool of studies; however, quite a large sum of papers remained. Examination of each paper yielded beneficial results on diagnosing, effective treatments, follow-up findings, and prognosis for each indeterminate lesion discussed. Overall, the literature search combined the molecular, histologic, immunohistochemical, surgical strategies to develop an up-to-date and comprehensive framework to guide physicians when encountering such lesions. The tumors reviewed include: kaposiform hemangioendothelioma, endovascular papillary angioendothelioma, pseudomyogenic hemangioendothelioma, retiform hemangioendothelioma, epithelioid hemangioendothelioma, and composite hemangioendothelioma.