Low-grade Leiomyosarcoma of the Cavernous Sinus in an HIV Positive Patient: Case Report.

Primary leiomyosarcomas of the central nervous system are extremely rare tumors, with few cases reported in the literature. In this article we report the case of a patient with an intracranial leiomyosarcoma of the cavernous sinus. This is the case of a 23-year-old man with a history of human immunodeficiency virus (HIV) and Epstein-Barr virus infection, with clinical picture of headache and left palpebral ptosis, who underwent nuclear magnetic resonance imaging that showed a lesion that occupied the cavernous sinus. Excisional biopsy reported fusocellular mesenchymal neoplasm with smooth muscle differentiation by immunohistochemistry compatible with low-grade leiomyosarcoma. The patient was initially taken to a partial resection, without treatment. Subsequently, the patient presented progression of his disease, so the area of neurosurgery considered that the lesion was unresectable due to its location and the risk of sequelae. It was then decided to treat the patient with intensity-modulated radiation therapy technique external radiotherapy. At six months of treatment, the patient continues asymptomatic with a stable disease.

Primary Conjunctival Rhabdomyosarcoma in a Pediatric Patient.

Rhabdomyosarcomas are neoplasms with a high degree of malignancy and arise from the embryonic mesenchyme. They represent approximately 5% of all pediatric tumors and their main locations are the head and neck (45%), trunk (40%), and extremities (15%). Twenty-five percent to 30% of the head and neck rhabdomyosarcomas appear in the orbit; however, its origin from the conjunctiva is rare, with few case reports published in the literature. We present the case of a five-year-old girl with a diagnosis of primary embryonic rhabdomyosarcoma of the conjunctiva, treated with surgery and chemotherapy. After completing the treatment, it was followed up with controls for oncological ophthalmology, pediatric hematology-oncology, and radiotherapy oncology every six months with magnetic resonance of the orbits. Two years after the end of treatment, the patient is disease-free. Conjunctiva rhabdomyosarcoma is a rare lesion, with few previously reported cases. In the reported case, the histopathological findings and positivity of the different immunohistochemical markers allowed a definitive diagnosis of rhabdomyosarcoma. The excellent prognosis of this pathology is probably linked to the early diagnosis of the disease and the timely administration of radical treatment. It is essential to be able to identify conjunctival rhabdomyosarcoma from its clinical and histopathological characteristics in order to achieve early diagnosis and provide adequate treatment to patients.

Abscopal Effect After Palliative Radiotherapy in a Patient with a Gastric Adenocarcinoma Disseminated to Retroperitoneal Space: Case Report from a Latin American Reference Center and Review of the Literature.

Radiation therapy is known to have a highly effective local and regional effect for cancer treatment; however, sporadic events of tumor regression in non-irradiated and irradiated fields have been observed over time, which is known as the "abscopal effect." In this report, we describe the case of a patient with a diagnosis of unresectable advanced gastric adenocarcinoma, who developed extensive retroperitoneal lymph node involvement and did not accept management with chemotherapy. Primary radiotherapy at the local level was offered to control hemostasis, reaching an important span of complete remission of the disease.