Endoscopic endonasal approach for resection of sellar leiomyosarcoma metastasis: illustrative case.

Background: Leiomyosarcoma (LMS) is a rare neoplasm that arises from tissues of embryonic mesodermal origin. Primary tissues of origin can include smooth muscle cells of the abdominopelvic viscera, blood vessels, or arrector pili muscles. LMS is known to metastasize to the lungs, with few reported cases of spread to the central nervous system.

Craniospinal irradiation for respiratory failure secondary to central nervous system Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis typically featuring lower extremity osteosclerosis (96%) from Langerin-negative histiocytes with fibrosis. Central nervous system (CNS)-only disease is extremely rare, and particularly difficult to diagnose and manage. Neurologic complaints may be refractory to systemic therapy (ST), and the role of radiation therapy (RT) is undefined.

Gliosarcoma with PNET features mimicking a metastatic neuroendocrine carcinoma: A diagnostic dilemma.

Objective: Gliosarcomas (GS) comprise ~ 2 - 8% of glioblastomas and are associated with a similar poor prognosis. GS have rarely been found with a primitive neuroectodermal component (PNET). We present a case of gliosarcoma with PNET features (GS-PNET) that mimicked a neuroendocrine carcinoma on initial biopsy.

Neuropathology of Pituitary Adenomas and Sellar Lesions.

The pituitary gland is the site of numerous neoplastic and inflammatory processes. The overwhelmingly most frequent tumors arise from cells of the anterior lobe, the pituitary neuroendocrine tumors (PitNETs). Immunohistochemistry assay staining for pituitary hormones is the core tool for classifying PitNETs, resulting in the diagnosis of somatotroph PitNETs, lactotroph PitNETs, and so on.

p16INK4A expression is frequently increased in periorbital and ocular squamous lesions.

Background: p16 expression is a well established biomarker of cervical dysplasia and carcinoma arising from high risk human papilloma virus infection. Increased p16 expression is also seen in squamous neoplasms arising at other sites, including head, neck, and oropharyngeal tract. Squamous lesions are also frequently encountered at ocular surface and peri-orbital skin sites, but the prevalence of increased p16 expression in these lesions has been poorly studied.