6-4 20 Grade Name Pathological Features Subtypes I Benign Well circumscribed -- II Atypical Three of five Choroids or clear cell Loss of lobularity Small cells Prominent nucleoli Increased cellularity Necrosis III Anaplastic Anaplasia
and Rhabdoid or papillary Brain invasion TABLE 2.
Rhabdomyosarcoma expression of both CK-MB and cTnT can be explained by tumor anaplasia
and concurrent expression of fetal phenotypes.
Most of the previously reported tumors have been classified as low-grade; they featured few mitotic figures, little anaplasia
, and varying proportions of all three cell types.
25) Hansemann contrasted his theory of anaplasia
(from the Greek, ana [backward] + plassein [to form]) to the more popular theory of embryonalism because embryonal tissues had remained undifferentiated while anaplastic tissues had once been differentiated.
Atypical mitoses, cellular anaplasia
, pleomorphic giant cells and lymphovascular invasion were absent.
A notable feature of our case was the absence of mitotic activity, anaplasia
, and bizarre cell forms--a finding that ruled out a leiomyosarcoma.
A variety of confusing terms were developed for these surface lesions, including anaplasia
and basal cell hyperplasia.
Prevalence and clinical impact of anaplasia
in childhood rhabdomyosarcoma : a report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group.
3) The tumor we describe belongs in this category, although our case is unique in view of our distinguishing findings of the absence of fibrosis and neuronal tissue and the presence of abundant gemistocytes, mild vascular proliferation, perivascular cuffing, mild cellular anaplasia
, and mitoses.
Histologically, TO can be divided into low-grade (mild to moderate nuclear atypia and few mitoses) and high-grade (poorly differentiated tumor with marked anaplasia
and high mitotic activity) cells.
3) More recent classification would have defined 4 of our biologically malignant papillary carcinoma cases with areas of various degrees of anaplasia
as anaplastic carcinoma.
Fibromatosis occupies an intermediary position, and microscopic sections contain markedly cellular lesions of mature proliferative fibroblastic tissue, with infrequent mitoses and occasional atypia, but no frank anaplasia
Rare examples of GISTs that show abrupt transformation from conventional KIT-positive tumor cells to KIT-negative cells with marked anaplasia
have been documented by Antonescu et al.
Based on their cellularity and degree of anaplasia
, chondrosarcomas are classified as either low-, medium-, or high-grade tumors.
10) Like Wilms tumor in which anaplasia
is a marker for chemoresistance and is associated with increased risk of tumor recurrence, (36) the undifferentiated component in retinoblastoma treated with neoadjuvant chemotherapy may represent a clone of the tumor cells resistant to chemotherapy and thus may help to predict the development of recurrence.