title: Ovarian mucinous tumor with malignant mural nodules: dedifferentiation or collision?
abstract: Ovarian mucinous tumors with mural nodules are rare surface epithelial-stromal tumors. The mural nodules are divergent neoplasms that may be benign or malignant. The latter may be in the form of a sarcoma, carcinosarcoma, anaplastic carcinoma, or a variety of other recognized histotypes of carcinoma, which raises the question of whether malignant mural nodules represent a form of dedifferentiation in ovarian mucinous tumors or whether they represent collision tumors. We recently reported the K-RAS gene mutation status in a case of ovarian mucinous adenocarcinoma with mural nodule of high-grade sarcoma. The mucinous and sarcomatous components revealed a mutation in codon 12 of the K-RAS gene of a different nucleotide substitution, indicating that these 2 tumor components were different clones of the same tumor. Herein, we are reporting another case of a 20-yr-old woman who presented with 22 cm pelvic mass, omental caking, and ascites. A diagnosis of invasive mucinous carcinoma with mural nodules of anaplastic carcinoma was rendered. K-RAS gene mutation studies revealed p.G12V, c.35G>T mutation in the 2 components of the tumor, which is the most common mutation reported in mucinous tumors of the ovary. The fact that sarcomatous or anaplastic carcinomatous mural nodules in ovarian mucinous tumors display the same K-RAS mutations as their underlying mucinous neoplasms provides supportive evidence that at least some malignant mural nodules represent a form of dedifferentiation in ovarian mucinous tumors, rather than a collision of 2 divergent tumor types.
authors.affiliation: Departments of Pathology, Microbiology and Immunology (M.M.D., O.F.) Obstetrics and Gynecology (D.K., M.A.C., O.F.), Division of Gynecologic Oncology, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Mohamed M
authors.initials: MM
authors.lastname: Desouki
authors.forename: Dineo
authors.initials: D
authors.lastname: Khabele
authors.forename: Marta A
authors.initials: MA
authors.lastname: Crispens
authors.forename: Oluwole
authors.initials: O
authors.lastname: Fadare
mesh_terms: D002277:Carcinoma / Q000175:diagnosis* / Q000473:pathology* / Q000628:therapy; D002465:Cell Movement; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D003131:Combined Modality Therapy; D004358:Drug Therapy; D005260:Female; D011905:Genes, ras / Q000235:genetics; D006801:Humans; D009154:Mutation / Q000235:genetics; D018297:Neoplasms, Cystic, Mucinous, and Serous / Q000175:diagnosis* / Q000473:pathology* / Q000628:therapy; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000628:therapy; D010052:Ovariectomy; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf