Desmoplastic small round cell tumors (DSRCTs) of the gastrointestinal (GI) tract are a rare and highly aggressive variant of soft tissue sarcomas, predominantly affecting the abdominal region. These tumors are believed to originate from multipotent mesenchymal stem cells or primitive progenitor cells. They are composed of small round tumor cells associated with prominent stromal desmoplasia, polyphenotypic differentiation, and EWSR1::WT1 gene fusion. Diagnostically, DSRCTs present a significant challenge due to their histological resemblance to other small round cell tumors, such as Ewing sarcoma and rhabdomyosarcoma, necessitating the use of ancillary tests, including immunopanels and molecular analysis, to reach a definitive diagnosis. Immunohistochemical staining, including markers like cytokeratin, vimentin, desmin, and WT1, has proven valuable in differentiating DSRCTs from their mimickers. The prognosis of these tumors is highly dependent on factors such as tumor location and stage at diagnosis, and given their aggressive nature, a multidisciplinary approach may be required that combines surgical resection, chemotherapy, and radiation therapy, among other options. In this review, we provide a synopsis of the pathophysiology of DSRCTs and the latest diagnostic advancements, including the utility of molecular profiling and novel biomarkers.

Basal cell carcinoma (BCC) is the most common dermatological malignancy in older adults. This chapter aims to capture relevant information as to the prevalence, risk factors, clinical presentation, and treatment modalities for BCC in older adults. There is a global increase in this pathology in terms of incidence and prevalence among older adults, with the burden of lifelong UV exposure and immunosuppression as major risk factors. This chapter discusses various subtypes of BCC as well as various other pathologies that may be mistaken for BCC. A variety of treatment modalities are discussed, including both surgical treatments and nonsurgical options such as topical therapies, radiation, and immunologic therapies. With such a varied arsenal of treatment options, pertinent considerations for treatment are elucidated with risks, benefits, and alternatives listed for the clinician’s considerations. A multifaceted approach considering the patients’ concerns, overall health, and cosmetic goals is crucial for optimizing outcomes for this particular patient population.