Department of Human Pathology and Oncology, Anatomic Pathology Section, University of Siena, Italy.
Histol Histopathol. 2012 Jul;27(7):941-7. doi: 10.14670/HH-27.941.
Myeloid sarcoma is a rare tumor composed of myeloid cells, localized in an extramedullary site, which may be associated with a concurrent myeloid neoplasm involving the bone marrow, although such an association is not required. Most patients present with acute myeloid leukemia and their prognosis is poor. We describe the case of a 76-year old woman with an adenocarcinoma of the right colon infiltrating the subserosa synchronous with a myeloid sarcoma at the same site; one pericolic lymph node was infiltrated by both tumors. The peculiarities of this case are the clinical presentation (as an acute abdomen due to subserosa infiltration by the myeloid sarcoma), the coexistence of a myeloid sarcoma with an adenocarcinoma of the right colon, and the absence of progression to acute leukemia. Coexistence of myeloid sarcoma and adenocarcinoma in the colon is probably incidental, and so it appears likely that the two different tumours arose from different mechanisms. However, a possible common background is conceivable. Some authors have found that p53 has a pivotal role in driving the maturation of myeloid stem cells and p53 is, also, involved in colon carcinogenesis. In our case, it may be hypothesized that synchronous heterogeneous mutations occurred in different types of committed cells or in stem cells secondary to p53 loss. Since only one case report has evaluated the correlation between myeloid sarcoma and adenocarcinoma of the large bowel, further immunohistochemical and molecular studies are needed to clarify the pathogenetic relationship between them.
骨髓肉瘤是一种由髓系细胞组成的罕见肿瘤，位于骨髓外部位，可能与同时累及骨髓的髓系肿瘤相关，但并非必需。大多数患者表现为急性髓系白血病，预后不良。我们描述了一例 76 岁女性的病例，其右侧结肠癌浸润浆膜下，同时在同一部位发生骨髓肉瘤；一个结肠旁淋巴结被两种肿瘤浸润。该病例的特点是临床表现（由于骨髓肉瘤浸润浆膜下引起的急性腹痛）、骨髓肉瘤与右侧结肠癌并存，且未进展为急性白血病。结肠骨髓肉瘤和腺癌共存可能是偶然的，因此这两种不同的肿瘤可能来自不同的机制。然而，可能存在共同的背景。一些作者发现，p53 在驱动髓系干细胞成熟中起着关键作用，p53 也参与结直肠癌的发生。在我们的病例中，可以假设在不同类型的定向细胞或 p53 缺失后的干细胞中同时发生了异质性突变。由于只有一份病例报告评估了骨髓肉瘤和大肠腺癌之间的相关性，因此需要进一步的免疫组织化学和分子研究来阐明它们之间的发病机制关系。
