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
BACKGROUND A malignant melanotic nerve sheath tumor(MMNST),previously known as a melanotic schwannoma,is a rare variant of a peripheral nerve sheath tumor composed of Schwann cells with melanotic differentiation.Only ...BACKGROUND A malignant melanotic nerve sheath tumor(MMNST),previously known as a melanotic schwannoma,is a rare variant of a peripheral nerve sheath tumor composed of Schwann cells with melanotic differentiation.Only a few reports of spinal MMNST have been reported.CASE SUMMARY In the first case,a 58-year-old woman presented with a history of low back pain and paresthesia.Magnetic resonance imaging(MRI)and computed tomography(CT)of the lumbar spine revealed an intradural extramedullary mass lesion with amorphous linear calcification.Complete tumor resection was performed and histological examination revealed a psammomatous melanotic schwannoma.In the second case,a 72-year-old man presented with low back pain and paresthesia.MRI of the thoracolumbar spine revealed an intramedullary mass lesion at the T11 vertebral body level.The mass lesion was hypointense on T2WI and hyperintense on T1WI.Tumor resection was performed and the histologic result was melanotic schwannoma.CONCLUSION MMNST should be considered in the differential diagnosis when calcification or melanin is seen in an intradural spinal tumor.展开更多
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
Melanotic schwannoma is a rare variant of schwannoma composed of melanin-producing cells with ultrastructural features of schwann cells. The description of the course of the tumors differs somewhat, but it is generall...Melanotic schwannoma is a rare variant of schwannoma composed of melanin-producing cells with ultrastructural features of schwann cells. The description of the course of the tumors differs somewhat, but it is generally considered as a benign lesion. We investigated the clinicopathologic features, immunophenotypes, and ultrastructural features of 13 patients with nonpsammomatous melanotic schwannoma （NPMS）.展开更多
BACKGROUND Anorectal melanoma (AM) is an extremely rare malignant tumor originating from anorectal melanocytes with a poor prognosis. AM has been reported to have a much lower incidence than cutaneous or choroid melan...BACKGROUND Anorectal melanoma (AM) is an extremely rare malignant tumor originating from anorectal melanocytes with a poor prognosis. AM has been reported to have a much lower incidence than cutaneous or choroid melanoma, accounting for 0.4%-1.6% of all melanomas. CASE SUMMARY We report a 76-year-old female patient diagnosed with anorectal malignant melanoma by colonoscopy and biopsy. Intraoperative examination revealed two distinct anorectal tumors, one melanotic and another amelanotic, as well as two pigmented mucosal zones at the dentate line level. Abdominal perineal resection was performed. A pathological report confirmed all four lesions to be melanomas. Postoperatively, we followed an immunotherapy protocol targeting PD-1 (nivolumab). The patient had 24 mo of disease-free follow-up upon completion of nivolumab treatment. CONCLUSION This is the first reported case presenting coexistence of pigmented and unpigmented AMs in the same patient.展开更多
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.
基金Supported by a Clinical Research Grant from Pusan National University Hospital(2020).
文摘BACKGROUND A malignant melanotic nerve sheath tumor(MMNST),previously known as a melanotic schwannoma,is a rare variant of a peripheral nerve sheath tumor composed of Schwann cells with melanotic differentiation.Only a few reports of spinal MMNST have been reported.CASE SUMMARY In the first case,a 58-year-old woman presented with a history of low back pain and paresthesia.Magnetic resonance imaging(MRI)and computed tomography(CT)of the lumbar spine revealed an intradural extramedullary mass lesion with amorphous linear calcification.Complete tumor resection was performed and histological examination revealed a psammomatous melanotic schwannoma.In the second case,a 72-year-old man presented with low back pain and paresthesia.MRI of the thoracolumbar spine revealed an intramedullary mass lesion at the T11 vertebral body level.The mass lesion was hypointense on T2WI and hyperintense on T1WI.Tumor resection was performed and the histologic result was melanotic schwannoma.CONCLUSION MMNST should be considered in the differential diagnosis when calcification or melanin is seen in an intradural spinal tumor.
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This work was supported by a grant from the China Medical Board ofNew York (No. CMB 00-722).
文摘Melanotic schwannoma is a rare variant of schwannoma composed of melanin-producing cells with ultrastructural features of schwann cells. The description of the course of the tumors differs somewhat, but it is generally considered as a benign lesion. We investigated the clinicopathologic features, immunophenotypes, and ultrastructural features of 13 patients with nonpsammomatous melanotic schwannoma （NPMS）.
文摘BACKGROUND Anorectal melanoma (AM) is an extremely rare malignant tumor originating from anorectal melanocytes with a poor prognosis. AM has been reported to have a much lower incidence than cutaneous or choroid melanoma, accounting for 0.4%-1.6% of all melanomas. CASE SUMMARY We report a 76-year-old female patient diagnosed with anorectal malignant melanoma by colonoscopy and biopsy. Intraoperative examination revealed two distinct anorectal tumors, one melanotic and another amelanotic, as well as two pigmented mucosal zones at the dentate line level. Abdominal perineal resection was performed. A pathological report confirmed all four lesions to be melanomas. Postoperatively, we followed an immunotherapy protocol targeting PD-1 (nivolumab). The patient had 24 mo of disease-free follow-up upon completion of nivolumab treatment. CONCLUSION This is the first reported case presenting coexistence of pigmented and unpigmented AMs in the same patient.
