Neutropenic Enterocolitis as a Complication of Autologous Stem Cell Transplant in Patients With Multiple Myeloma: A Case Series.

Neutropenic enterocolitis (NE) is a rare but severe complication occurring in neutropenic patients undergoing intensive chemotherapy. Mortality is high, so early diagnosis is required to start urgent medical or surgical treatment. Data analysis of the development of NE after hematopoietic stem cell transplantation remains scarce. The aim of this case series is to discuss five out of 100 patients receiving autologous stem cell transplants (ASCTs) for multiple myeloma complicated with NE between 2016 and 2020 in the hematology department of the Cheikh Khalifa International University Hospital, Casablanca, Morocco. The patients were diagnosed with IgA and IgG multiple myeloma and aged between 58 to 64 years. They received induction therapy with four cycles of a triplet regimen including a proteasome inhibitor, an immunomodulatory drug, and corticosteroids, allowing a complete remission. Intensification was based on ASCT with melphalan at 200 mg/m2. The period of aplasia was marked by the sudden appearance of NE, diagnosed based on clinical, biological, and imaging criteria. Treatment included antibiotherapy and supportive care. We report no complications in our cases, nor the need for surgical care. Therefore, we consider that early diagnosis and treatment allowed a good evolution in our case series. The management of NE must be multidisciplinary associating hematologists, gastroenterologists, radiologists, and biologists. More studies and trials are needed to establish specific diagnostic criteria and better treatment options.

Kikuchi-Fujimoto's Disease or Histiocytic Necrotizing Lymphadenitis Following mRNA COVID-19 Vaccination: A Rare Case.

Kikuchi-Fujimoto disease (KFD), also known as necrotizing histiocytic lymphadenopathy, is a rare and benign lymph node disorder that mainly occurs in young women. It is clinically characterized by fever with tender and painful cervical lymphadenopathy mostly; however, all areas of lymph nodes can be involved. This disorder is often mistaken for malignant lymphoma or infection. The precise pathophysiology of KFD remains unknown, but it is theorized that it may be post-viral or associated with an autoimmune disease. The diagnosis is based on the histological analysis of the excised involved lymph node. The treatment is mainly supportive with favorable outcomes within a few weeks or months. In this case, we present a 24-year-old woman without a past medical history, who consulted for painful bilateral cervical lymphadenopathy associated with fever that has been evolving for one month following the coronavirus disease 2019 (COVID-19) vaccination. The initial diagnostic workup was performed and the diagnosis of KFD was confirmed based on the histopathological findings of the excised lymphadenopathy. Therapeutic management was based on oral corticosteroid treatment with clinical and radiological improvement after a few days without recurrence during follow-up. This article aims to report a rare case of KFD in a patient after receiving the messenger ribonucleic acid (mRNA)-based COVID-19 vaccine. Therefore, this case highlights the possible association between COVID-19 vaccination and KFD and this should be considered in the differential diagnosis.

An Unusual Presentation of Extramedullary Relapse Following Blinatumomab in Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia.

In adult patients, extramedullary relapse (EMR) in B-acute lymphoblastic leukemia (B-ALL) has a pejorative prognosis, especially after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Blinatumomab, a bispecific CD3/CD19 antibody, is approved for relapsed/refractory acute lymphoblastic leukemia (ALL) and has proven its efficacy with good complete response (CR) rates and molecular responses in several trials. Unusual sites of relapse following treatment with blinatumomab for ALL are rarely reported. We describe the case of a 23-year-old male with B-ALL characterized as Philadelphia chromosome-positive without extramedullary lesions at diagnosis. He benefited from a matched-related donor allo-HSCT at first remission. A relapse in the bone marrow and central nervous system was diagnosed four months later. A treatment with blinatumomab was initiated with the obtention of CR after one cycle. During the third cycle of blinatumomab, multiple sites of EMR occurred initially with a painless swelling appearing in the areolas and the nipples, followed by bilateral testicular hypertrophy and moderate paraplegia. A diagnosis of leukemic infiltration on the areola-nipple complex was made by cytological analysis of the fine-needle aspiration of the left areola. The analysis of bone marrow was normal, but molecular BCR-ABL was positive. Systemic chemotherapy with hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, and dexamethasone) and cycles of blinatumomab with nilotinib was initiated in association with intrathecal chemotherapy and whole-brain radiation therapy. Clinical, molecular, and central nervous remissions were obtained. We report this case to describe multiple sites of EMR of B-ALL with atypical breast infiltration in an adult male patient following treatment with blinatumomab.