Melanotic neuroectodermal tumor of infancy (MNTI) is a rare benign, locally invasive neoplasm afflicting the infant more often in the craniofacial region. The current understanding is that this tumor’s origin is neur...Melanotic neuroectodermal tumor of infancy (MNTI) is a rare benign, locally invasive neoplasm afflicting the infant more often in the craniofacial region. The current understanding is that this tumor’s origin is neural crest cells. The typical presentation is that a rapidly growing non-ulcerated anterior maxillary mass occurs in an infant usually less than six months old. This tumor may involve other areas including the ovaries, epididymis, femur, mandible, and brain. We present that an 8-month-old infant with a maxillary lesion of MNTI appeared encapsulated, which is a hitherto unreported feature. Investigations leading to the diagnosis and the management of the case are also presented. The need to report cases of this rare entity cannot be overemphasized as this will go a long way in adding new knowledge about its biological nature.展开更多
BACKGROUND Melanotic Xp11-associated tumors are rare mesenchymal-derived tumors. So far,most primary melanotic Xp11-associated tumors have been reported in the kidney, and reports of this tumor in the gastrointestinal...BACKGROUND Melanotic Xp11-associated tumors are rare mesenchymal-derived tumors. So far,most primary melanotic Xp11-associated tumors have been reported in the kidney, and reports of this tumor in the gastrointestinal tract are rare.CASE SUMMARY Here we describe the case of a 25-year-old woman who presented with a melanotic Xp11-associated tumor in the sigmoid colon. Colonoscopy revealed a large mucosal bulge in the sigmoid colon, approximately 32 cm inside the anus.The surface was rough with local erosion. The tumor was brittle on biopsy and bled easily. Computed tomography revealed thickening of the rectal wall with edema. Postoperative pathology indicated the likelihood of a perivascular epithelioid cell tumor. Histologically, the tumor comprised plump epithelioid cells with abundant clear to lightly eosinophilic cytoplasm and round nuclei arranged in an alveolar or trabecular pattern. The tumor cells were strongly positive for HMB-45, Melan-A, Cathepsin K, and TFE3 but negative for vimentin,smooth muscle actin, S100 protein, CD10, CK20, and desmin. The tumor cells had a low Ki-67 labeling index(approximately 2%). Fluorescence in situ hybridization revealed TFE3 fracture. Based on these histologic and immunohistochemical features, a diagnosis of melanotic Xp11-associated tumor of the sigmoid colon was made.CONCLUSION In summary, we report the clinicopathological features of a primary tumor that is extremely rare in the sigmoid colon and review the clinicopathological characteristics of melanotic Xp11-associated tumors, compatible with the very rare tumor termed "melanotic Xp11 translocation renal cancer" in all aspects.展开更多
文摘Melanotic neuroectodermal tumor of infancy (MNTI) is a rare benign, locally invasive neoplasm afflicting the infant more often in the craniofacial region. The current understanding is that this tumor’s origin is neural crest cells. The typical presentation is that a rapidly growing non-ulcerated anterior maxillary mass occurs in an infant usually less than six months old. This tumor may involve other areas including the ovaries, epididymis, femur, mandible, and brain. We present that an 8-month-old infant with a maxillary lesion of MNTI appeared encapsulated, which is a hitherto unreported feature. Investigations leading to the diagnosis and the management of the case are also presented. The need to report cases of this rare entity cannot be overemphasized as this will go a long way in adding new knowledge about its biological nature.
基金Supported by The Key Research & Development and Transformation Project of Qinghai Province for 2018(No.2018-SF-113)
文摘BACKGROUND Melanotic Xp11-associated tumors are rare mesenchymal-derived tumors. So far,most primary melanotic Xp11-associated tumors have been reported in the kidney, and reports of this tumor in the gastrointestinal tract are rare.CASE SUMMARY Here we describe the case of a 25-year-old woman who presented with a melanotic Xp11-associated tumor in the sigmoid colon. Colonoscopy revealed a large mucosal bulge in the sigmoid colon, approximately 32 cm inside the anus.The surface was rough with local erosion. The tumor was brittle on biopsy and bled easily. Computed tomography revealed thickening of the rectal wall with edema. Postoperative pathology indicated the likelihood of a perivascular epithelioid cell tumor. Histologically, the tumor comprised plump epithelioid cells with abundant clear to lightly eosinophilic cytoplasm and round nuclei arranged in an alveolar or trabecular pattern. The tumor cells were strongly positive for HMB-45, Melan-A, Cathepsin K, and TFE3 but negative for vimentin,smooth muscle actin, S100 protein, CD10, CK20, and desmin. The tumor cells had a low Ki-67 labeling index(approximately 2%). Fluorescence in situ hybridization revealed TFE3 fracture. Based on these histologic and immunohistochemical features, a diagnosis of melanotic Xp11-associated tumor of the sigmoid colon was made.CONCLUSION In summary, we report the clinicopathological features of a primary tumor that is extremely rare in the sigmoid colon and review the clinicopathological characteristics of melanotic Xp11-associated tumors, compatible with the very rare tumor termed "melanotic Xp11 translocation renal cancer" in all aspects.
