The term small round blue cell is frequently used as a cursory radiologic pathological correlation of aggressive tumors throughout the body. Rhabdomyosarcoma MMP11 is the most common childhood soft tissue tumor and often arises from the head, neck, and genitourinary system.[4] Isolated thoracic rhabdomyosarcomas are unusual but can arise from the heart, lungs, pleura, airways, or mediastinum.[4] Radiographically, they 956697-53-3 often present as a soft tissue mass, which erodes into the adjacent bone tissue. Metastatic disease can present as pulmonary/pleural nodules [Shape 5]. The unifying histomorphologic feature can be neoplastic cells that resemble embryonic skeletal myoblasts, which screen positive immunostaining for myogenin and/or MyoD1 [Shape 6]. Open up in another window Shape 5 13-year-old male showing with a coughing identified as having embryonal rhabdomyosarcoma. (a and b) Axial and coronal computed tomography pictures on soft cells home windows demonstrate a multilobulated remaining anterior mediastinal mass (arrows). (c) Following PET check out demonstrates that FDG avid lesion can be contiguous using the pericardium (arrow). Open up in another window Shape 6 Pathology from individual in Shape 5. (a) Gross pathology displays a tan, badly circumscribed tumor (arrow). (b) Fascicles of fusiform cells (H and E, 100). (c) Positive immunoreactivity for myogenin confirms primitive skeletal muscle tissue differentiation (brownish, arrow). DESMOPLASTIC Little Circular CELL TUMOR Desmoplastic little circular cell tumors are uncommon neoplasms which typically occur in the belly and present with stomach discomfort.[5] Radiologic imaging shows multiple abdominopelvic masses having a dominant mass due to the retrovesical/retrouterine space.[5] Thoracic dissemination may express as pulmonary nodules or pleural involvement [Shape 7].[5] The determining histologic feature is that of desmoplastic stroma enveloping irregular nests of cells [Shape 8]. Positive immunostaining for vimentin [Shape 8] and t(11;22)(p13;q12) chromosomal translocation are distinguishing features.[6] Open up in another window Shape 7 12-year-old female with remaining shoulder pain identified as having desmoplastic small circular tumor. (a) Axial computed tomography section on lung home windows demonstrate a pulmonary nodule in the proper lower lobe, which progressively enlarged more than a yr (b) (arrows). Open up in another window Shape 8 Pathology from individual in Shape 7. (a) Gross pathology displays grey-white pulmonary nodules with foci of necrosis and hemorrhage (arrow). (b) Multiple sharply demarcated nests surrounded by prominent desmoplastic stroma (arrows) (H and E, 100). (c) Positive immunoreactivity for vimentin confirms mesenchymal differentiation (brown, arrow). EXTRANODAL MARGINAL B-CELL LYMPHOMA Extranodal marginal B-cell lymphoma or mucosa-associated lymphoid tissue, often arises from the gastrointestinal tract.[7] Within the lungs, they can present as metastatic disease or primary bronchial-associated lymphoid tissue lymphoma. Radiographically, they appear as lung nodules/masses or airspace consolidations [Figure 9].[8] Immunohistochemically, these neoplastic cells typically express IgM and stain strongly for CD20 [Figure 10]. Open in a separate window Figure 9 A 56-year-old female with abdominal pain diagnosed with gastric extranodal marginal B-cell lymphoma. (a) Four years after diagnosis, computed tomography images on lung windows demonstrate a spiculated lesion at the right lung apex (arrow) with subsequent growth over a year (b and c) (arrows). Open in a separate window Figure 10 Pathology from patient in Figure 9. (a) Architectural effacement by the proliferation of atypical lymphoid cells, which show centrocyte, 956697-53-3 monocytoid, and plasmacytoid features on 400 (H and E, 100) (b). (c) Strong membranous immunoreactivity for CD20 confirms B-cell lineage (brown, arrow). POSTTRANSPLANT LYMPHOPROLIFERATIVE DISORDER PTLDs are lymphoid or plasmacytic proliferations that develop as a consequence of immunosuppression following organ transplantation. The abdomen is most frequently involved. Thoracic 956697-53-3 manifestations are less common, presenting as randomly distributed pulmonary nodules [Figure 11].[9] A characteristic feature of PTLD is 956697-53-3 its association with EpsteinCBarr virus infection, which can be detected by EpsteinCBarr encoding region hybridization [Figure 12]. Open in a separate window Figure 11 A 10-year-old female status postliver transplant for Wilson disease identified as having the posttransplant lymphoproliferative disease. (a-c) Axial and coronal computed tomography areas on lung home windows display two pulmonary nodules in the remaining lower lobe ten weeks after transplant (arrows). Open up in another window Shape 12 Pathology from individual in Shape 11. (a) Effacement of regular architecture from the proliferation of huge atypical lymphoid cells (H and E, 100). (c) Solid reactivity for Compact disc20 confirms B-cell lineage (brownish, arrow)..