1/2. Coexistence of spindle cell lipoma and ordinary lipoma.We report a patient with a spindle cell lipoma on the nape and three ordinary lipomas on the abdomen and extremities. The coexistence of spindle cell lipoma and ordinary lipoma in a single patient is rare. Abundant CD34-positive spindle cells and mast cells were found in the spindle cell lipoma, but in the ordinary lipomas, only a small number of CD34-positive spindle cells were found in the interstitial connective tissue and no mast cells were seen. Because mast cells are known to stimulate mesenchymal cell proliferation and collagen production, mast cell infiltration may be a trigger for the proliferation of CD34-positive spindle cells, leading to the conversion of ordinary lipoma into spindle cell lipoma.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
2/2. Combined morphologic and karyotypic study of 59 atypical lipomatous tumors. Evaluation of their relationship and differential diagnosis with other adipose tissue tumors (a report of the CHAMP Study Group).Fifty-nine cases of atypical lipomatous tumors (ALT) of soft tissue (atypical lipomas, well-differentiated liposarcomas) were studied morphologically and cytogenetically as part of an international collaborative study. Forty-nine cases were deeply seated (including retroperitoneum), and 10 were superficial. Clonal chromosomal abnormalities were found in 55 cases (93%). Supernumerary ring or giant marker chromosomes (RGCs), the sole consistent alteration, were found in 37 ALTs (63%). They were more common in tumors that were large (p < 0.001), deeply seated (p < 0.005), that contained lipoblasts (p < 0.05), and that had marked cytologic atypia (p < 0.05). In a relatively short follow-up period (average, 3 years), only three of 59 cases recurred, one resulting in the patient's death. All three cases had RGCs. Also, five of the six cases that underwent dedifferentiation had RGCs, indicating that RGCs are associated not only with low-grade malignant behavior (in the form of local recurrence) but also with the potential for tumor progression. When the karyotypic profile of ALT was compared with that of 233 other types of adipose tissue tumors similarly analyzed by the authors, a statistically highly significant correlation (p < 0.0001) was found between ALT and RGCs. These results support the existence of ALT as a distinct tumor subtype that is different from ordinary lipoma and from spindle or pleomorphic lipoma, albeit histogenetically closely related to them. It also supports the proposed pathogenetic link between ALT and dedifferentiated liposarcoma. The association between chromosomal and morphologic findings indicates the potential role of karyotypic analysis in the differential diagnosis of ALT with ordinary lipoma, spindle or pleomorphic lipoma, hibernoma, and myxoid liposarcoma.- - - - - - - - - - ranking = 0.047201348184328keywords = spindle (Clic here for more details about this article) |