Twists and Turns: Unmasking Myeloproliferative Neoplasms Through Surgical Complications of Wandering Spleen

Introduction/Background/Significance: Massive splenomegaly is a hallmark manifestation of advanced myeloproliferative neoplasms (MPNs), particularly primary myelofibrosis (PMF) and chronic myeloid leukemia (CML). The spleen's role in extramedullary hematopoiesis leads to significant enlargement, which can be clinically silent or cause mechanical complications such as early satiety, abdominal discomfort, and cytopenias due to cell sequestration. Rarely, splenomegaly may lead to acute abdominal emergencies including splenic torsion or gastrointestinal obstruction. Ectopic or wandering spleen, often associated with ligamentous laxity or mass effect, can predispose patients to torsion and related complications. Though infrequent, such presentations may serve as the initial indicator of an undiagnosed MPN. This case series presents two patients in whom life-threatening splenic complications led to the eventual diagnosis of an underlying hematologic malignancy.

Materials and Methods/Case Presentation/Objective: Case 1 is a 56-year-old male with a long-standing abdominal mass who presented with postprandial pain. Imaging revealed a wandering, torsed spleen with a splenic index of 1809. He underwent splenectomy, which revealed viable splenic tissue. Peripheral smear showed leukoerythroblastic features with dacryocytes and nucleated red cells. Bone marrow biopsy revealed grade 3 myelofibrosis with increased, clustered megakaryocytes. A diagnosis of PMF was made. Postoperatively, the patient developed thrombocytosis managed with hydroxyurea and anagrelide.

Case 2 is a 26-year-old female with progressive abdominal distension, constipation, and weight loss. Imaging revealed massive splenomegaly causing mechanical large bowel obstruction. Emergency laparotomy revealed extrinsic colonic compression by an intact spleen. Resection and colostomy were performed. CBC showed marked leukocytosis, anemia, and thrombocytosis. Bone marrow and FISH confirmed BCR::ABL1-positive CML. She was started on imatinib, resulting in hematologic improvement and reduction in spleen size.

Results/Description/Main Outcome Measures: These cases demonstrate severe splenic complications as first presentations of underlying MPNs. In Case 1, splenic torsion led to the diagnosis of PMF, while in Case 2, mechanical bowel obstruction unmasked CML. Torsion of a wandering spleen, although rare, should be suspected in patients with unexplained abdominal pain and mobile splenic position. Bowel obstruction due to splenomegaly is even rarer, with few reported cases. In both scenarios, surgical intervention was essential. Preservation of the spleen is preferred, but splenectomy may be warranted when the organ is structurally unstable, technically non-fixable, or when it causes significant mass effect. In PMF, splenectomy carries risk of postoperative cytoses and long-term complications and should be reserved for symptomatic patients unresponsive to medical therapy. In CML, splenectomy is rarely indicated due to the efficacy of tyrosine kinase inhibitors but may play a palliative role in selected advanced cases. These cases also highlight the value of peripheral smear and bone marrow biopsy in identifying underlying MPNs when CBC findings are subtle or non-specific.

Conclusions: Massive splenomegaly may be the first and only manifestation of an undiagnosed MPN. Acute complications such as torsion or bowel obstruction require prompt surgical management and often serve as the gateway to hematologic diagnosis. Hematologists should consider MPNs in patients with splenomegaly even when CBC findings are equivocal. Early recognition and multidisciplinary care are crucial for timely diagnosis, splenic preservation when possible, and appropriate treatment initiation.