Serous carcinomatous component championed by heparin-binding EGF-like growth factor (HB-EGF) predisposing to metastasis and recurrence in stage I uterine malignant mixed mullerian tumor.

The stage I uterine malignant mixed mullerian tumor (MMMT) shows different potential for progression. We reason that MMMTs with high-grade carcinomatous component and positivity for HB-EGF are prone to recurrence/metastasis in the early stage. A retrospective clinical and histopathologic review with immunohistochemical staining for HB-EGF, EGFR, and integrin-α5 was performed for 62 surgically staged MMMT cases. Recurrence/metastasis (RM) is 6/18 (33%) in stage I disease. Of all the clinicopathologic variables and biomarkers analyzed for stage I MMMT, serous carcinomatous component (83% [5/6] versus 17% [1/12], P = .0015) and HB-EGF expression (100% [6/6] versus 50% [6/12], P=.0339) were significantly different between groups with RM and without RM. The presence of serous carcinoma in all stages was 83% (5/6) in stage I with RM, 8% (1/12) in stage I without RM, 20% (1/5) in stage II, 36.4% (8/22) in stage III and 64.7% (11/17) in stage IV; this was paralleled by HB-EGF expression of 100% (6/6), 50% (6/12), 40% (2/5), 50% (11/22) and 71% (12/17) with a correlation coefficient r=0.9131 (P=.027). HB-EGF and integrin-α5 were highly expressed in MMMTs bearing serous carcinoma component, compared to endometrioid and unclassifiable/miscellaneous subtypes (84.6%/47.6%/33.3%, P=.025 for HB-EGF; and 61.5%/42.9%/20.0%, P=.021 for integrin-α5). The EGFR positivity was comparable among the three subtypes (48.1%, 47.6% and 26.7%, P=.326). This study indicates that serous carcinomatous component championed by expression of HB-EGF predisposes to recurrence/metastasis in stage I MMMT. This process might involve integrin-α5 and does not seem to require overexpression of EGFR. Further study is required.

Immunohistochemical staining with EGFR mutation-specific antibodies: high specificity as a diagnostic marker for lung adenocarcinoma.

We previously demonstrated a high specificity of immunohistochemistry using epidermal growth factor receptor (EGFR) mutation-specific antibodies in lung adenocarcinoma and correlation with EGFR mutation analysis. In this study, we assessed EGFR mutation status by immunohistochemistry in a variety of extrapulmonary malignancies, especially those that frequently show EGFR overexpression. Tissue microarrays containing triplicate cores of breast carcinomas (n=300), colorectal carcinomas (n=65), pancreatic adenocarcinoma (n=145), and uterine carcinosarcoma or malignant mixed müllerian tumors (n=25) were included in the study. Tissue microarray of lung adenocarcinoma with known EGFR mutation status was used as reference. Immunohistochemistry was performed using antibodies specific for the E746-A750del and L858R mutations. In pulmonary adenocarcinoma, a staining intensity of 2+ or 3+ correlates with mutation status and is therefore considered as positive. Out of 300 breast carcinomas, 293 (98%) scored 0, 5 (2%) had 1+ staining, 2 (1%) were 2+ for the L858R antibody. All breast carcinomas scored 0 with the E746-A750 antibody. All the colorectal, pancreatic carcinomas and malignant mixed müllerian tumors were negative (0) for both antibodies. Molecular analysis of the breast carcinomas that scored 2+ for L858R showed no mutation. Our results show that EGFR mutation-specific antibodies could be an additional tool distinguishing primary versus metastatic carcinomas in the lung. False-positivity can be seen in breast carcinoma but is extremely rare (1%).

Mullerian adenosarcomas: an immunophenotypic analysis of 35 cases.

Mullerian adenosarcomas (MAs) are rare mixed mesenchymal and epithelial neoplasms that occur most commonly in the uterus. Although the epithelial component is typically benign, the mesenchymal component of most adenosarcomas morphologically resembles that observed in endometrial stromal tumors and is responsible for their clinical behavior. Thus, the differential diagnosis usually includes not only low-grade endometrial stromal tumors, but also adenofibroma, carcinosarcoma, and embryonal rhabdomyosarcoma especially in small samples. The objective of this study was to ascertain the immunophenotypic profile of the epithelial and mesenchymal components of MAs and delineate possible differences between conventional mesenchymal areas and areas of sarcomatous overgrowth. Representative sections from 35 MAs, 28 of them without sarcomatous overgrowth (MA-NSO) and 7 with sarcomatous overgrowth (MA-SO), were included in the study. Thirty tumors arose in the uterus, 4 were pelvic, and 1 originated in the colon. Adequate blocks were selected and immunostained for estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), CD10, WT1, smooth muscle actin, desmin, AE1/3 cytokeratin, CD34, calretinin, inhibin, c-kit, and Ki-67. The mesenchymal component expressed ER in 21/27 MA-NSOs but in only 1/7 MA-SOs (65% overall). PR was expressed in 21/26 MA-NSOs and 4/7 MA-SOs (76% overall), whereas AR was positive in 10/27 MA-NSOs and 5/7 MA-SOs (35% overall). CD10 was expressed in 23/28 MA-NSOs but in only 2/7 MA-SOs (71% overall), and WT1 positivity was seen in 22/27 MA-NSOs and 6/7 MA-SOs (79% overall). Sixty-seven percent of MAs expressed smooth muscle actin, 32% desmin, including both examples of MA-SOs with rhabdomyoblastic differentiation, and 25% expressed AE1/3 cytokeratin. CD34 expression was found in 35% of the tumors, but it was almost always patchy in distribution and weak in intensity, as was calretinin expression, seen only in 12% of the cases. Expression of c-kit and inhibin in greater than 5% of the tumor cells was not encountered. The median and mean Ki-67 labeling indices were 10% and 12%, respectively (range, <5% to 40%). The median and mean Ki-67 indices were both 5% in MA-NSOs compared with 30% and 28%, respectively, in MA-SOs. The epithelial compartment demonstrated expression for ER (24/32), PR (23/31), and AE1/3 cytokeratin (33/33); rare cases expressed CD10 (4 cases) and AR (1 case). In summary, the immunophenotype of most MAs resembled that of endometrial stromal tumors (positive for ER, PR, WT1, and CD10, with variable expression of muscle markers, AR and cytokeratin). The proliferative rate in the stromal component was strongly related to the presence of sarcomatous overgrowth. ER, PR, and CD10 expression was lost in MA-SOs relative to conventional low-grade stromal areas of mullerian/mesodermal adenosarcomas, reflecting the "dedifferentiation" of this component.

Malignant mixed mullerian tumor of the vagina: case report with review of the literature, immunohistochemical study, and evaluation for human papilloma virus.

The patient was a 57-year-old white woman who presented with a 3.0 x 2.0-cm partially ulcerated vaginal polyp. Histology revealed a malignant mixed mullerian tumor composed of invasive squamous cell carcinoma with deeper areas of undifferentiated pleomorphic sarcoma. Invasive carcinoma had overlying high-grade vaginal intraepithelial neoplasia (VaIN III), which contained koilocytic atypia. In situ hybridization detected high-risk human papillomavirus DNA in both the carcinoma and the sarcoma components.

The P2X7 receptor: a novel biomarker of uterine epithelial cancers.

OBJECTIVE: To determine expression of the P2X(7) receptor in normal and in cancer uterine tissues. The rationale was that the receptor P2X(7) regulates constitutive apoptosis in uterine epithelial cells, and previous studies showed diminished P2X(7)-mediated apoptosis in cancer uterine cells compared with normal cells. METHODS: A clinical, experimental feasibility study. Normal (n = 42) and cancer uterine tissues (n = 47) were obtained from a total of 72 women ages 25 to 75. End points for P2X(7) mRNA were quantitative PCR and in situ hybridization, and end points for P2X(7) protein were Western blots and immunostaining using anti-P2X(7) antibody. RESULTS: (a) In normal uteri, P2X(7) mRNA and protein were expressed predominantly in the epithelial (endometrial, endocervical, and ectocervical) cells. (b) Expression of the P2X(7) mRNA and protein was absent from endometrial and endocervical adenocarcinoma tissues and from cervical squamous cell carcinoma tissues. (c) In cervical dysplasia, P2X(7) protein was absent in the dysplastic lesions. (d) Semiquantitative analysis using P2X(7) mRNA (normalized in each tissue to the constitutive glyceraldehyde-3-phosphate dehydrogenase) and P2X(7) protein levels (normalized in each tissue to the constitutive tubulin) revealed that P2X(7) mRNA and/or protein levels can distinguish uterine normal from cancer tissues at high degrees of sensitivity (92%, 100%) and specificity (100%, 90%). SUMMARY AND CONCLUSIONS: (a) Levels of the P2X(7) are lower in uterine epithelial cancer tissues than in the corresponding normal tissues. (b) The data suggest that tissue P2X(7) mRNA and protein levels could be used as a novel biomarker to differentiate normal and cancer uterine epithelial tissues.

Caveolin-3 is a sensitive and specific marker for rhabdomyosarcoma.

Caveolin-3 (Cav-3) is a principal structural protein of caveolae membrane domains. Animal studies have revealed that Cav-3 is expressed in skeletal and cardiac myocytes but absent in other types of cells. Recent studies have shown that abnormalities in the Cav-3 gene are associated with some forms of muscular dystrophy, while skeletal muscle abnormalities have been observed in Cav-3 transgenic and knockout mice. In this study the authors evaluated the distribution of Cav-3 in normal human tissues and compared the expression of Cav-3 with that of myogenin and myoD1 in rhabdomyosarcoma (RMS), malignant mixed mullerian tumor (MMMT), and an array of neoplasms that mimic RMS to assess the utility of Cav-3 as a diagnostic marker for tumors with skeletal muscle differentiation. In nonneoplastic human tissues, crisp membrane staining for Cav-3 was present in cardiac and skeletal myocytes and occasionally in arterial smooth muscle cells and prostatic stromal cells, while other cell types were negative for Cav-3. Eighty-eight percent (21/24) of RMS studied were positive for Cav-3. Positive staining was generally observed in the more maturely differentiated tumor cells but not the primitive tumor cells. Eight of nine cases of MMMT stained strongly with Cav-3 in their rhabdomyosarcomatous component but not in other components. Fifty-four other neoplasms (13 leiomyosarcomas, 8 neuroblastomas, 5 lymphomas, 6 Wilms tumors without skeletal muscle differentiation, 5 Ewing sarcomas, 4 malignant fibrous histiocytomas, 4 angiosarcomas, 6 malignant melanomas, and 3 synovial sarcomas) were negative for Cav-3 expression. Nearly all (96% [23/24]) cases of RMS were positive for myogenin, while 88% (21/24) were positive for myoD1. Primitive tumor cells showed significantly increased expression of myoD1 and myogenin; conversely, more differentiated tumor cells were negative or weakly stained. The rhabdomyosarcomatous component of MMMT stained focally with myogenin and myoD1, in contrast to the strong Cav-3 labeling in these cells. These results demonstrate that Cav-3 is specifically expressed in human cardiac and skeletal myocytes. Furthermore, its high specificity and relatively high sensitivity (88%) for tumors with skeletal muscle differentiation suggest that Cav-3 is a valuable marker for these tumors and may be used to assess the degree of differentiation of RMS and to identify residual tumor cells in post-chemotherapy specimens.

Primary mesenteric malignant mixed mesodermal (müllerian) tumor with neuroendocrine differentiation.

Extragenital malignant mixed mesodermal (müllerian) tumors (MMMT) are rare neoplasms, with but 24 well documented cases in the literature. Neuroendocrine differentiation in mixed müllerian neoplasms has been mentioned only anecdotally. We report on the clinical, pathological, and immunohistochemical features of a hitherto-undescribed extragenital MMMT with prominent neuroendocrine differentiation arising from the jejunal mesentery. This lesion was composed of a poorly differentiated epithelial component and a spindle cell component with heterologous (rhabdomyoblastic) differentiation. The bulk of the tumor consisted of small cell neuroendocrine carcinoma, which exhibited strong immunoreactivity for NSE, LEU-7, chromogranin A and synaptophysin. Electronmicroscopy confirmed the presence of neurosecretory dense-core granules. The primary mesenteric origin of the tumor was established at autopsy. Along with a brief review of previously reported extragenital MMMT some histogenetic concepts relevant to this case are discussed.

Adenomyolipoma of the uterus: a case report.

Adenomyolipoma of the uterus is a rare, benign, polypoid lesion considered to be of hamartomatous origin or represent an unusual type of benign Müllerian mixed tumour with a heterologous element. The authors present a case of uterine adenomyolipoma and discuss its pathogenesis. A 62-year-old woman complained of lower abdominal pain and postmenopausal bleeding. Imaging techniques revealed a solid ovarian mass and a polypoid intrauterine lesion. The frozen section diagnosis of the ovarian mass was a thecoma. A total hysterectomy and bilateral salpingo-oophorectomy were performed. On gross examination a pedunculated, polypoid lesion of 7x4.5x3cm was found in the uterine cavity. Microscopically, the polypoid lesion contained both epithelial and mesenchymal elements. The epithelial elements were endometrial glands of various size, formed by proliferative endometrial cells. The mesenchymal elements were composed of endometrial stroma, smooth muscle and mature adipocytes. Both the epithelial and the mesenchymal elements showed a benign appearance, were intermingled with each other and periglandular stromal condensation was absent. The lesion had an irregular surface. Microscopic diagnosis was an adenomyolipoma. The peculiar shape and microscopic features of this lesion suggested that it was a variant of benign Müllerian mixed tumour.

[Malignant mesodermal (Mullerian) mixed tumor of the ovary: histologic, immunohistochemical and cytologic study]. / Zlokachestvennaia mezodermal'naia (miullerovskaia) smeshannaia opukhol' iaichnika: gistologicheskoe, immunogistokhimicheskoe i tsitologicheskoe issledovanie.

A rare case of aggressive ovarian tumor in a 38-year-old female is described. Cytological diagnosis of the intraoperative smears was difficult because of the presence of the epithelial and non-epithelial components. The latter consisted of two types: spindle cells and roundish undifferentiated cells with multinuclear forms. Histologically, it was a malignant mesodermal (Mullerian) mixed tumor. Round mesenchymal cells expressed desmin and vimentin while spindle cells expressed myoglobin. Non-epithelial component was verified as leiomyosarcoma and rhabdomyosarcoma. Cells of the epithelial component expressed cytokeratins and epithelial membrane antigen.

Prognostic factors in uterine carcinosarcoma: a clinicopathologic study of 25 patients.

BACKGROUND: Carcinosarcoma (malignant mixed mullerian tumor) of the female genital tract is a highly malignant neoplasm. The tumor stage and histologic grade of the carcinomatous component are among the important prognostic indicators cited in the literature for this tumor. METHODS: Twenty-five patients with uterine carcinosarcoma at 4 hospitals in the Kyoto and Nara areas of Japan were studied retrospectively. The clinicopathologic and immunohistochemical data including p53, bcl-2, Ki-67, and proliferating cell nuclear antigen (PCNA) staining were analyzed using univariate and multivariate analysis with the Cox proportional hazards model to investigate potential prognostic indicators for this neoplasm. RESULTS: The 5-year survival rate was 36.4% for all stages, 62.3% for Stage I, and 0% for Stages II-IV. From the univariate analysis, stage (P = 0.0001), endometrioid adenocarcinoma as a carcinomatous component (P = 0.0006), age (P = 0.0355), and a heterologous sarcomatous component (P = 0.0421) were found to be prognostically significant for patient survival. Stage was the only independent significant factor in the multivariate analysis (t = 2.212). None of the other factors (history of pregnancy and gestation, gross appearance of the tumors, grade of the carcinomatous component, mitotic count of the sarcomatous component, Ki-67 and PCNA reactivity, or p53 or bcl-2 positive staining) was found to be a significant prognostic indicator. CONCLUSIONS: Stage appears to be the only definite independent prognostic indicator of survival in patients with uterine carcinosarcoma. It is uncertain whether age, endometrioid adenocarcinoma as a carcinomatous component, or absence of a heterologous component in the sarcomatous area are prognostic factors. Immunohistochemical expression of p53, bcl-2, Ki-67, or PCNA is not a prognostic indicator. The immunohistochemical results of the current study may support the hypothesis of a common stem cell origin of this tumor.

Malignant mixed Müllerian tumors of the uterus: a clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 44 cases.

AIM: The authors retrospectively analyzed the prognostic significance of p53, mdm-2, DNA ploidy, S-phase fraction (SPF), and traditional clinical and pathologic factors in patients with malignant mixed Müllerian tumors (MMMT) of the uterus. METHODS: Between 1970 and 1995, 44 uterine tumors were diagnosed as MMMT (21 stage I, 2 stage II, 10 stage III, and 11 stage IV). Thirty-two were homologous type and 12 were heterologous type. DNA flow cytometry and immunohistochemical analysis for p53 and mdm-2 overexpression were performed on paraffin-embedded archival tissue. RESULTS: 68% of the tumors were nondiploid and 61% had an SPF greater than 10%. Sixty-one percent overexpressed p53 and 25% were mdm-2-positive. Furthermore, 91% of the tumors had a mitotic count greater than 10/10 hpf and 95% had high-grade cytologic atypia. Twenty-seven (61%) patients died of tumor and 6 (14%) died of intercurrent disease. Eleven (25%) patients are alive with no evidence of disease. The median follow-up for patients still alive was 59 months (range, 28-178 months). The overall 5-year survival rate was 38%. In a univariate analysis that included stage, histologic type, DNA ploidy, SPF, p53, mdm-2, mitotic index, and age, and with survival as the end point, only stage reached statistically prognostic significance. CONCLUSION: The majority of the tumors had obvious signs of aggressiveness such as high grade, high mitotic count, nondiploid pattern, high SPF, and overexpression of p53. This study found that stage is the most important prognostic factor for survival in MMMTs of the uterus.

Tumors of the uterine isthmus: clinicopathologic features and immunohistochemical characterization of p53 expression and hormone receptors.

Five (3%) of 161 endometrial cancers treated surgically between 1988 and 1992 were classified as primary isthmic tumors, and their clinicopathologic features, p53 expression, and hormone receptor status were evaluated. Three were endometrioid adenocarcinomas with squamous differentiation, one was a mixed serous and clear cell carcinoma, and one was a malignant müllerian mixed tumor; all five were high grade, invaded the entire thickness of the myometrium, and exhibited lymphatic space invasion. Four of the five patients had extrauterine metastases identified at the time of hysterectomy. All five patients died due to progressive disease with the survival time ranging from 1 to 23 months. Abnormal p53 gene expression was identified immunohistochemically in three of the five isthmic tumors. Weak positivity for estrogen and progesterone receptors was demonstrated in one case, with the remaining four being negative. Tumors arising in and confined to the uterine isthmus are unusual and, in our series, were uniformly aggressive with an unfavorable prognosis. The histopathologic features and biologic behavior of the isthmic tumors appeared similar to those of other high-grade endometrial cancers arising in the uterine corpus.

Immunohistochemical study of c-erb B-2 expression in malignant mixed müllerian tumors of the female genital tract.

OBJECTIVE: To study the expression of c-erb B-2 in gynecologic malignancies, especially in malignant mixed müllerian tumors (MMTs). METHODS: Using immunohistochemical techniques, we examined 6 cases of primary MMT, 6 cases of leiomyosarcoma (LMS), 7 cases of endometrial adenocarcinomas, and 10 cases of normal endometria. RESULTS: The expression of c-erb B-2 was observed in the carcinomatous area of all 6 cases of MMT (100%), the sarcomatous area of 5 of 6 cases of MMT (83.3%), in 1 of the 6 cases of LMS (16.7%), in all 7 cases of adenocarcinoma (100%), and in all cases of normal epithelial cells (100%), but was not observed in any of the cases of normal stromal cells (0%). CONCLUSION: The results suggest that the carcinomatous and sarcomatous elements of MMT are similar in their expression of c-erb B-2. MMT differed immunohistochemically from pure sarcoma cells and normal stromal cells, but resembled pure carcinoma cells and normal epithelial cells of the female genital tract.

Clinicopathologic and mucin histochemical analyses of 90 cases of ovarian mucinous borderline tumors of intestinal and müllerian types.

Clinicopathologic and mucin histochemical characteristics of 90 cases of ovarian mucinous borderline tumors (MBT) of intestinal (IMBT) and müllerian types (MMBT) were studied to determine whether IMBT and MMBT constitute distinct tumor subtypes. The IMBT (77 cases, 78 lesions) contained goblet cells, absorptive cells and endocrine cells, which represented intestinal differentiation. The average diameter of IMBT was 13.4 cm. Five patients (6.5%) had stage III disease with pseudomyxoma peritonei and one of them died from tumor. Approximately 50% of IMBT demonstrated gastrointestinal characteristics on mucin histochemistry. The MMBT (13 cases, 14 lesions) consisted of mucous columnar cells and eosinophilic cells, with no intestinal differentiation. MMBT accounted for 15.2% of MBT. MMBT averaged 8.4 cm in diameter, and 29% were associated with endometriosis of the Ipsilateral ovary. All patients with MMBT had stage I disease, and none suffered from pseudomyxoma peritonei. All patients whose follow-up data were available were alive and well, without evidence of tumor recurrence. The mucin histochemical findings in MMBT resembled those of normal endocervix. Results of the present study suggest that IMBT and MMBT have different characteristics and constitute distinct subtypes of MBT.

Epidermal growth factor receptor and c-erbB-2 oncoprotein expression in female genital tract carcinosarcomas (malignant mixed müllerian tumors). Clinicopathologic study of 82 cases.

BACKGROUND: Epidermal growth factor receptor (EGFR) and c-erbB-2 (also known as HER-2/neu) oncoprotein (p185erbB-2) are members of the subfamily of tyrosine kinase, transmembrane receptors often implicated in human carcinogenesis. We hypothesize that expression of EGFR and p185erbB-2 adds useful prognostic and histogenetic information regarding female genital tract carcinosarcomas (FGTCSs). METHODS: Paraffin sections from 82 FGTCS (61 endometrium, 14 ovary, 5 cervix, and 2 fallopian tube), 56% of which exhibited heterologous elements, were stained using anti-EGFR (clone 31G7, Triton Diagnostics, Alameda, CA) and anti-p185erbB-2 (clone CB11, Novocastra Labs, UK). RESULTS: EGFR reactivity was present in 11 (13.4%) FGTCSs (55% carcinomatous component [CC] only, 18% sarcomatous component [SC] only, and 27% in both). EGFR was associated with adenosquamous histology of the CC (P < 0.05) and heterologous rhabdomyosarcomatous differentiation in the SC (P < 0.05); no other histopathologic features were correlated. p185erbB-2 reactivity was present in 79 (87.8% strong [S], 78% membrane [M], and 8.5% weak) FGTCSs (1% CC only, 0% SC only, and 99% in both). p185erbB-2 did not correlate with histopathologic features or EGFR. Seventy-seven patients had clinical follow-up for longer than 12 months. Approximately 49.3% and 72.3% of patients had recurrent disease by 12 and 80 months, respectively; all but 1 were dead from disease. 27% of patients were disease free after 15 to 307 months (median, 77 months; mean, 92 months). EGFR, but not p185erbB-2 expression predicted disease recurrence (P < 0.05). Recurrent disease was associated with Stage greater than I (P < 0.0001), vascular space invasion in resection specimens (P < 0.01), and deep myometrial invasion in hysterectomies (P < 0.05). EGFR was associated with Stage greater than I and did not help predict recurrence in good prognosis groups. CONCLUSIONS: p185erbB-2 overexpression in both CC and SC of FGTCS suggests a common carcinogenic mechanism for both components and supports the conversion-histogenesis hypothesis implicating a dominant role for the CC with the SC arising as a metaplastic change from the CC. EGFR may be expressed in either component and indicates aggressive biologic behavior; however, its prognostic utility is limited by its low predictive value for recurrence (40.3%), inability to foretell recurrence in good prognosis groups, and dependence on stage. High frequency of overexpression and dismal prognosis make FGTCS patients good candidates for trials of therapeutic strategies involving the p185erbB-2 receptor manipulations.

Overexpression of the c-myc proto-oncogene occurs frequently in uterine sarcomas.

Overexpression of the c-myc proto-oncogene occurs in carcinoma of the ovary, endometrium, and cervix, and is associated with an adverse prognosis, but little is known about the pattern of c-myc expression in uterine sarcomas. This study investigates the expression of c-myc in uterine smooth muscle tumors and malignant mixed müllerian tumors. Twenty-three leiomyosarcomas, 10 leiomyomas, and 9 malignant mixed müllerian tumors were examined for c-myc overexpression by immunohistochemistry. Differences in mitotic rate and in survival were compared in c-myc positive and negative cases of leiomyosarcoma. Overexpression of c-myc was seen in 6/12 leiomyomas, 11/23 leiomyosarcomas, and 9/9 malignant mixed müllerian tumors. Positive staining was restricted to a perinuclear location in all of the leiomyomas and one leiomyosarcoma. Diffuse cytoplasmic staining was seen in the remaining 10 positive leiomyosarcomas. Positive staining was seen in both epithelial and stromal elements of malignant mixed müllerian tumors, including homologous and heterologous areas of stromal differentiation. There was no significant difference in mitotic rate or in survival between c-myc positive and negative cases of leiomyosarcoma. Overexpression of c-myc occurs in many uterine leiomyosarcomas and the majority of malignant mixed müllerian tumors. Overexpression of c-myc also occurs in benign uterine smooth muscle tumors but with a different pattern than that seen in malignant tumors. This overexpression does not correlate with survival and the significance of overexpression of c-myc in these tumors is unclear.

Primary malignant mixed Müllerian tumor (metaplastic carcinoma) of the female peritoneum. A clinical, pathologic, and immunohistochemical study of three cases and a review of the literature.

BACKGROUND: Malignant mixed mesodermal tumors (malignant mixed Müllerian tumors [MMMT]) occur rarely in extragenital sites. METHODS: The authors analyzed the clinical, pathologic, and immunohistochemical features of three cases of primary MMMT of the female peritoneum. RESULTS: The neoplasms occurred in 60-, 64- and 84-year-old women and arose from pelvic peritoneum. Two patients died with disseminated disease 8 and 24 months postoperatively. The third died of cardiac failure 12 months postoperatively with questionable metastatic disease. Microscopically, two tumors were of the heterologous type, containing foci of rhabdomyosarcomatous (case 1) and chondrosarcomatous (case 3) differentiation. Immunohistochemically, coexpression of keratin and vimentin was observed focally in both carcinomatous and sarcomatous components in all three neoplasms, whereas coexpression of low molecular weight cytokeratin, vimentin and actin was observed focally in case 2. Rhabdomyosarcomatous areas were positive with desmin and actin, and chondrosarcomatous areas for S-100 protein. Both epithelial and mesenchymal components were positive for alpha-1 antichymotrypsin in all cases. CONCLUSIONS: On the basis of the present cases and a review of 15 reports from the literature, primary MMMT of the female peritoneum proved to be a rare but highly malignant neoplasm occurring in elderly postmenopausal women. Of 15 patients with available follow-up, 12 died with disease, mostly within 1 year, regardless of the initial tumor stage, histology (homologous versus heterologous MMMT) or treatments attempted. The tumor developed within pelvic peritoneum in half the cases. Histogenetically, peritoneal MMMT are thought to represent "metaplastic" carcinomas originating from the secondary Müllerian system.

p53 immunostaining suggests that uterine carcinosarcomas are monoclonal.

The histogenesis of carcinosarcomas has intrigued pathologists for a long time and remains unresolved. Two main theories have been put forward, one suggesting that they are monoclonal, another suggesting that they are biclonal. Our study examined p53 immunostaining in 17 uterine carcinosarcomas (mixed Müllerian tumours) and found positivity in five (30%). There was no disparity in immunostaining between the epithelial and the stromal components in any of the 17 tumours. This concordance in every tumour would be very unlikely if carcinosarcomas are biclonal. However, it would be expected if carcinosarcomas are monoclonal.