Myeloid sarcoma of the small intestine in a patient without overt acute myeloid leukaemia: a challenging diagnosis of a rare condition

Primary ileal myeloid sarcoma presenting with bowel obstruction: a case report

BACKGROUND

Myeloid sarcoma (MS) is an extramedullary tumor constituted by myeloid blasts or immature myeloid cells. It frequently occurs in conjunction with acute myeloid leukemia (AML); however, it can exceptionally manifest in patients without leukemia. Here, we present a rare case of primary MS originating in the small bowel without evidence of bone marrow involvement.

CASE REPRESENTATION

A 33 year-old female with no relevant medical history was admitted to our hospital with recurrent abdominal pain. Computed tomography (CT) revealed bowel obstruction due to thickening of the ileum wall, which was suspected to be an ileal tumor. Initially, ectopic endometriosis was suspected because of abdominal pain associated with the menstrual cycle and changes observed on a follow-up CT scan. The lesion could not be detected by double-balloon endoscopy. Despite conservative treatment, the obstruction persisted, and laparoscopic partial ileal resection was performed, which revealed extensive involvement of the ileum and mesentery. Additionally, the mesentery of the resected ileum was extremely thickened. Histopathological and immunohistochemical examinations of the surgical specimen indicated ileal MS. Bone marrow aspiration after discharge was negative for cytological findings of leukemia, leading to a final diagnosis of primary ileal MS. Her postoperative course was uneventful, and she is currently undergoing systemic chemotherapy tailored to AML at another hospital.

CONCLUSIONS

Even though MS of the small bowel is rare and may not be considered preoperatively, similar surgical treatment to that of other small bowel malignancies can ensure proper postoperative diagnosis and appropriate chemotherapy. Given the potential need for chemotherapy, ensuring surgical safety that allows for its rapid initiation is critical.

Gastrointestinal Myeloid Sarcoma a Case Presentation and Review of the Literature

Myeloid sarcomas can be detected in up to 30% of acute myeloid leukemia cases or occur de-novo without bone marrow involvement. The most frequent localization of myeloid sarcomas in the abdominal cavity is the small intestine, and gastric presentations are infrequent, frequently misdiagnosed, and a high level of suspicion should exist when the characteristic histomorphology features are present. The current review features a case report with gastric presentation of myeloid sarcoma in a patient with a diagnosis of acute myeloid leukemia with trisomy 8. In addition, a review of the literature of intestinal-type myeloid sarcomas shows that less than 15% of these cases have been reported in the stomach. The most common molecular aberrancy detected in intestinal myeloid sarcomas is the fusion protein CBFB-MYH11. A review of several large studies demonstrates that the presence of myeloid sarcoma does not constitute an independent prognostic factor. The therapeutic approach will be tailored to the specific genetic abnormalities present, and systemic chemotherapy with hematopoietic stem cell transplant is the most efficient strategy.

Hematologic malignancies of the gastrointestinal luminal tract

Hematologic malignancies include several lymphoproliferative and myeloproliferative disorders, many of which are frequently encountered in current health care settings. These malignancies frequently affect the gastrointestinal (GI) tract, either by secondary extranodal or extramedullary extension to the GI tract, or as a primary process arising in the GI tract. In fact, the GI tract may represent the most common extranodal site of involvement in many of them, such as lymphoma. Furthermore, in the current era of improved cancer treatment and advanced transplant procedures with increased survival, it has been quite common to encounter GI involvement by these malignancies through the disease course. Post-transplant lymphoproliferative disorder following kidney transplantation, for example, very commonly involves the GI tract. Other conditions that can involve the GI tract include multiple myeloma, plasmacytoma, myeloid sarcoma, mastocytosis, and Castleman disease. Imaging diagnosis of these malignancies can be challenging, since they are much less common than primary GI cancers and both share many common imaging features as well. However, certain imaging features, particularly in combination with a matching clinical scenario, play a pivotal role in diagnosing these conditions and directing further evaluation. In this article, we review common and rare hematologic malignancies of the GI tract and discuss their pathophysiologic, clinical, and imaging features.