Malignant Gastric PEComa: A Rare Malignancy

Introduction: Perivascular epithelioid cell tumor (PEComa) is characterized by its perivascular location and spindle appearance of tumor cells with clear to lightly granular eosinophilic cytoplasm and a round-to-oval centrally located nucleus. Immunohistochemically, nearly all PEComas show reactivity for melanocytic (HMB-45 and/or melan-A) and smooth muscle (actin and/or desmin) markers. Malignant gastric PEComa is extremely rare and only 3 cases have been reported to best of our knowledge. We report a 4th case of malignant gastric PEComa.Case presentation: We are presenting a case of a 48 year-old Caucasian female who presented to the emergency department with complaint of abdominal pain for 3-4 weeks associated with intermittent nausea and vomiting. CT Abdomen/Pelvis with contrast showed a mass at the greater curvature of the distal stomach. Patient underwent resection of the mass and pathology result was consistent with malignant PEComa.Conclusion: PEComas are a family of rare mesenchymal tumors, composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. These tumors co-express, the muscle and melanotic markers. Surgical resection is the best treatment option. Most commonly, they arise in the retroperitoneum and colon is most the common site followed by small intestine in the GI tract

Erdheim-Chester disease presenting at the central nervous system

Erdheim-Chester disease is a rare non-Langerhans cell histiocytosis (LCH) that affects different body systems. It was recently recognized as a neoplastic disorder after identifying an activating mutation of the MAPK pathway. Neurological presentations of ECD are rare. We present a case of a 35-year-old male who presented to the emergency department with neck pain, headache and vomiting for 2 months; MRI showed multiple heterogeneous intracranial masses. Neurosurgery performed a suboccipital craniotomy, partially resected the cerebellar mass, and placed a parietal to frontal shunt catheter. Biopsy results from the cerebellar mass demonstrated cerebellar tissue involved by a diffuse proliferation of foamy histiocytes and spindle cells admixed with prominent lymphoplasmacytic infiltrate and positive for CD68, CD163, Factor XIIIa and Fascin. PET scan showed hypermetabolic uptake within the medullary portions of the diffuse abnormal lesions of the distal femurs, tibias, and fibulas, and cardiac MRI was nonsignificant. The patient was started on vemurafenib and continued to show improvement in a 3-month outpatient follow-up