Unusual Synchronous Association of Solid Tumors with Hematological Malignancies in Multiple Primary Cancers: Case Series and Literature Review

The incidence of synchronous multiple primary malignancies (MPMs), which include both solid and hematological malignancy, is considered very rare. In addition, the involvement of sites such as brain, thyroid, and breast are among the least reported in such complex conditions. Here we report five different types of solid tumors including glioblastoma multiforme, thyroid papillary carcinoma, breast invasive ductal carcinoma, colon cancer, and gastric adenocarcinoma that were associated with synchronous five different hematological malignancies in the form of T-cell lymphoblastic non-Hodgkin lymphoma (NHL), nodal marginal zone NHL, diffuse large B-cell NHL, Hodgkin lymphoma, and gastric mucosa-associated lymphoid tissue marginal zone NHL, respectively. The diagnosis of MPMs can be challenging, and there is no standard treatment for such difficult primary malignancies. However, the management of these conditions should be individualized using tumor board discussion and ensuring multidisciplinary coordinated care, besides considering treatment of the more aggressive malignancy before that with the less malignant potential.