Epstein–Barr virus–associated smooth‐muscle tumors (EBV‐SMTs) are unique and rare neoplasms described in immunocompromised patients. The case describes a nine‐year‐old female with a history of acute lymphoblastic leukemia with relapse and subsequent allogeneic bone marrow transplantation who presented with multiple EBV‐SMTs of the liver. EBV utilizes the mammalian target of rapamycin (mTOR) pathway for tumor growth, and sirolimus, a mTOR inhibitor, has shown to result in a short‐term response. We now report an extended treatment response with sirolimus in a pediatric patient with an EBV‐SMT.

Fibrin-associated diffuse large B cell lymphoma (FA-DLBCL) is a rare Epstein-Barr viruspositive B cell lymphoma that is nonmassforming, does not directly produce symptoms, and is incidentally discovered on histological examination of tissues excised for other reasons. Despite overlap in morphologic and immunophenotypic features with aggressive B cell neoplasms, FA-DLBCL shows an excellent clinical outcome, even with surgical excision alone. We report an extremely rare occurrence of FA-DLBCL found in association with a metallic implant on revision arthroplasty of the knee. This report also illustrates the need for an integrated multidisciplinary approach for accurate diagnosis and avoidance of overtreatment.

Mucormycosis is a fungal infection primarily afflicting immunocompromised or diabetic patients. Its presentation ranges from rhino-orbito-cerebral infections to disseminated mucormycosis with angioinvasion. We present a patient who developed a bowel obstruction one month after bone marrow transplant and was diagnosed with Rhizopus arrhizus diverticulitis despite antifungal therapy since transplantation. She underwent surgical removal with immediate fungal resurgence, declined further invasive intervention and was discharged on palliative isavuconazole. Seven months later she is alive with fungal containment.