Immunohistochemistry (Ki-67 and p53) as a tool in determining malignancy in smooth muscle neoplasms (exemplified by a myxoid leiomyosarcoma of the uterus)

Primary gigantic leiomyosarcoma of the liver treated with portal vein embolization and liver resection

Primary hepatic leiomyosarcoma (PHL) is an extremely rare tumor. The tumor has no specific presentations and often diagnosis is delayed until it reaches a significant size. We report the case of a 69-year-old female presented with a huge PHL. Due to size of the tumor and to be operable, the patient subjected to right portal vein embolization (PVE) and selective embolization of segment V. Four weeks after the PVE, liver resection was conducted (Segments V+VI bisegmentectomy plus resection of IVA). The patient had an uncomplicated post-operative course, and discharged at the 8th post-operative day. Diagnosis of PHL was confirmed by histopathological and immunohistochemical examinations. The patient refused to receive adjuvant chemotherapy, and revealed evidence of recurrence six months after the operation, and finally died 12 months after the operation and 16 months after initial diagnosis. PHL is an extremely rare tumor and often in first presentation has significant size. Radical surgery with adjuvant chemotherapy is key feature for prolonged survival.

Imaging features of primary hepatic leiomyosarcoma: A case report and review of literature

Primary hepatic leiomyosarcoma (PHL) is an extremely rare tumour. This tumour is difficult to diagnose by imaging examinations due to its rarity, and non-specific conventional imaging manifestations and clinical presentation. The present study reports the case of a 42-year-old male with PHL that was confirmed by histopathological and immunohistochemical examinations. Multimodal imaging examinations, including ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography-CT and digital subtraction angiography, were performed. The imaging manifestations were analysed and the associated literature was reviewed. The results found that no characteristic imaging appearance was present on ultrasound or plain CT scan. However, on unenhanced MRI, the tumours presented with a heterogeneous low signal density on T1-weighted imaging (WI) and a high signal density on T2WI and diffusion-WI. On gadopentetate dimeglumine enhanced MRI, the lesions were not enhanced during the arterial and portal venous phases; by contrast, these lesions were evidently enhanced during the 5-min delayed phase. Therefore, the delayed imaging of enhanced MRI is likely to be used to differentiate PHL from other hepatic tumours.

Targeted genomic analysis of Müllerian adenosarcoma

Müllerian adenosarcoma (MA) is a rare mixed mesenchymal tumour of the female genital tract, composed of malignant stroma and benign-appearing epithelium. Sarcomatous overgrowth (SO) is the only established histological variable associated with higher stage and shorter survival. Specific molecular or immunohistochemistry (IHC) tools for the diagnosis of MA are lacking. Our goal was to study genomic mutations and copy number variations (CNVs) in MA to understand better its pathobiology, and develop specific diagnostic and prognostic tools. DNA was extracted from 20 samples of MA from 18 subjects (12 without SO and 6 with SO), including two in which areas of both typical MA histology and SO were independently tested. Samples were analysed using a targeted next-generation sequencing assay interrogating exonic sequences of 275 cancer genes for mutations and CNVs as well as 91 introns across 30 genes for cancer-associated rearrangements. The mean number of mutations in MA with SO (mean 9.7; range 3-14) did not differ significantly from that in MA without SO (mean 9.6; range 5-16). MA with SO had significantly higher mean numbers of gene-level CNVs (24.6) compared to MA without SO (5; p = 0.0002). The most frequent amplification involved MDM2 and CDK4 (5/18; 28%), accompanied by focal CDK4 and MDM2 and diffuse HMGA2 expression using immunohistochemistry. MYBL1 amplification was seen in 4/18 (22%), predominantly in SO. Alterations in PIK3CA/AKT/PTEN pathway members were seen in 13/18 (72%). Notably, TP53 mutations were uncommon, present in only two cases with SO. Three out of 18 (17%) had mutations in ATRX, all associated with SO. No chromosomal rearrangements were identified. We have identified a number of recurrent genomic alterations in MA, including some associated with SO. Although further investigation of these findings is needed, confirmation of one or more may lead to new mechanistic insights and novel markers for this often difficult-to-diagnose tumour.

A rare occurrence of primary hepatic leiomyosarcoma associated with epstein barr virus infection in an AIDS patient

Primary hepatic leiomyosarcoma is exceedingly rare accounting for less than 1% of the hepatic tumors. Close to 45 cases have been reported in the English literature. Presentation is usually nonspecific and diagnosis is often delayed until tumors reach a large size. This leads to a dismal prognosis. The tumors are not yet fully understood, hence the standard of care is not well defined. Curative resection remains the mainstay of management. Close association of Epstein Barr virus (EBV) induced soft tissue sarcomas is proven, especially in the presence of immunosuppression encountered in HIV/AIDS patients and in posttransplant patients. We herein present a case report of a 54-year-old man diagnosed to have HIV/AIDS and EBV infection admitted to our hospital with complaints of intractable hiccups for more than a week. Extensive workup revealed primary leiomyosarcoma of the liver.

Co-existence of three rare gynecological tumors in a 79-year-old woman

The occurrence of two primary tumors simultaneously is relatively common. However, the occurrence of three kinds of gynecological tumors simultaneously is extremely rare. Here we presented a 79-year-old woman who had simultaneously three primary gynecological tumors which were relatively uncommon. Those tumors were myxoid leiomyosarcoma and endometrial mucinous adenocarcinoma in the uterus and a Leydig cell tumor in the right ovary. Uterine myxoid leiomyosarcoma is a very rare and aggressive variant of uterine sarcoma despite of its minimal even no atypia and a little mitotic activity. Mucinous endometrial adenocarcinoma is also a rare subtype which comprise only 0.6-5% of uterine cancers. Leydig cell tumor is a very rare ovarian tumor which is composed entirely or predominantly of Leydig cell.

Uterine smooth muscle tumors of uncertain malignant potential (STUMP): a clinicopathologic analysis of 16 cases

BACKGROUND

The current World Health Organization classification indicates that a uterine smooth muscle tumor that cannot be histologically diagnosed as unequivocally benign or malignant should be termed "smooth muscle tumor of uncertain malignant potential" (STUMP). STUMPs represent a heterogeneous group of rare tumors that have been the subject of only a few published studies, some of which lack detailed clinicopathologic details and/or follow-up data. More recently, it has been suggested that immunohistochemical staining may be helpful in the diagnosis of STUMPs.

DESIGN

The clinicopathologic features of 16 cases of STUMP that exhibited usual smooth muscle differentiation, diagnosed between 1992 and 2006 from 11 hospitals, were studied and classified into 4 subgroups using terminology and criteria described by Stanford investigators. Immunohistochemical stains for p16, p53, MIB1 (ki-67), and estrogen and progesterone receptors were performed. The results were compared with those in the literature.

RESULTS

The tumors were classified as follows: 6 as "atypical leiomyoma with limited experience", 7 as "smooth muscle tumor of low malignant potential", 2 as "atypical leiomyoma, low risk of recurrence," and 1 as "mitotically active leiomyoma, limited experience." Follow-up was 21 to 192 months (mean, 80.8 and median, 51.5). Only 2 tumors recurred, at 15 and 51 months, respectively; both were atypical leiomyoma with limited experience (multifocal moderate-to-severe atypia, no tumor cell necrosis, and mitotic counts of 4 and 5 mitotic figures /10 high-power fields, respectively). Both tumors had areas that were indistinguishable from benign leiomyoma and both had diffuse immunoreactivity for p16 and p53. Six other tumors that had focal staining for these markers all had a benign outcome. Both patients with recurrence were alive at last follow-up (at 40 and 74 mo). All the other patients were alive and disease-free.

CONCLUSIONS

This and other studies suggest that uterine tumors classified as STUMPs using criteria proposed by Stanford investigators are usually clinically benign but should be considered tumors of low malignant potential because they can occasionally recur, in some cases, years after hysterectomy. After a mean follow-up of 80.8 months, only 2 of 16 tumors in this study recurred. Both of the latter tumors fulfilled the criteria for atypical leiomyoma with limited experience. Notably, the 2 recurrent tumors were the only ones that were strongly immunoreactive for p16 and p53, supporting earlier observations that these markers may be helpful in the prediction of the behavior of STUMPs. Patients diagnosed with STUMPs should receive long-term surveillance.

Myocardin functions as an effective inducer of growth arrest and differentiation in human uterine leiomyosarcoma cells

Myocardin is an important transcriptional regulator in smooth and cardiac muscle development. We noticed that the expression of myocardin was markedly downregulated in human uterine leiomyosarcoma cells. Restoration of myocardin expression induced the reexpression of smooth muscle marker proteins and the formation of well-developed actin fibers. A concomitant increase in the expression of a cyclin-dependent kinase inhibitor, p21, led to significantly reduced cell proliferation, via p21's inhibition of the G(1)-S transition. A p21 promoter-reporter assay showed that myocardin markedly increased p21's promoter activity. Furthermore, a serum response factor (SRF)-binding cis-element CArG box in the p21 promoter region was required for this myocardin effect. Chromatin immunoprecipitation and DNA-protein binding assays showed that myocardin indirectly bound to the CArG box in the p21 promoter through the interaction with SRF. Furthermore, immunohistochemistry revealed that the levels of myocardin and p21 were both lower in leiomyosarcoma samples than in normal smooth muscle tissue. Taken together, our results indicate that the downregulation of myocardin expression facilitates cell cycle progression via the reduction of p21 expression in human leimyosarcomas and suggest that myocardin could be a useful therapeutic target for this disease.

The management of patients with uterine sarcoma: a debated clinical challenge

Uterine sarcomas include a heterogeneous group of rare tumours that usually have an aggressive clinical behaviour and a poor prognosis. Total abdominal hysterectomy and bilateral salpingo-oophorectomy represents the standard surgical treatment. Pelvic and/or para-aortic lymphadenectomy is indicated for carcinosarcoma, but not for leiomyosarcoma and undifferentiated endometrial sarcoma. Some recent data on low numbers of patients with low-grade endometrial stromal sarcoma appear to show an incidence of nodal involvement higher than previously expected, thus suggesting a role for lymphadenectomy in this malignancy. Carcinosarcoma also requires a comprehensive surgical peritoneal staging. Postoperative treatment of uterine sarcomas has been long debated. Adjuvant pelvic radiotherapy appears to improve local control without any significant impact on overall survival. There is little evidence in the literature supporting the use of adjuvant chemotherapy in any gynaecological sarcomas except for carcinosarcomas. However, uterine sarcomas have a high tendency to develop distant recurrences, and recent data on adjuvant chemotherapy in soft tissue sarcomas are promising. As for the drugs to be used, it is worth noting that in a Swiss study, the combination of ifosfamide (IFO) and doxorubicin (DOX) obtained similar response rates in advanced gynaecological sarcomas and in advanced soft tissue sarcomas of other sites. In our decision-making scheme for early-stage disease, patients with leiomyosarcoma or undifferentiated endometrial sarcoma should receive adjuvant doxorubicin/epidoxorubicin (EPIDX)+ifosfamide, and those with carcinosarcoma should be treated with adjuvant cisplatin (CDDP)-based chemotherapy. The same drug regimens are used for the treatment of advanced disease. Sequential pelvic radiotherapy following chemotherapy could be delivered to selected cases. Recurrent disease often requires the integration of different therapeutic modalities, but no curative option is currently available with the possible exception of surgery for lung metastases and hormone therapy with or without debulking surgery for recurrent low-grade endometrial stromal sarcoma. Patients should be encouraged to enter clinical trials designed to identify new active drugs for these malignancies.

Uterine leiomyosarcomas are characterized by high p16, p53 and MIB1 expression in comparison with usual leiomyomas, leiomyoma variants and smooth muscle tumours of uncertain malignant potential

AIMS

It has been suggested that p16 is overexpressed in uterine leiomyosarcomas in comparison with leiomyomas. In this study, p16 immunohistochemical expression was assessed in a variety of uterine smooth muscle tumours, including usual leiomyomas, leiomyoma variants, smooth muscle tumours of uncertain malignant potential (STUMPs) and leiomyosarcomas. The aim was to ascertain whether there are differences in p16 expression between these groups and whether p16 is of potential value in the assessment of problematic uterine smooth muscle neoplasms. p16 expression was also compared with that of p53 and MIB1.

METHODS AND RESULTS

Cases of usual leiomyoma (n = 10), leiomyoma variants (n = 27), STUMP (n = 4) and leiomyosarcoma (n = 22) were subject to p16, p53 and MIB1 immunohistochemistry. For p16, cases were evaluated with respect to both staining distribution and intensity. There was a statistically significant difference in p16 distribution (P < 0.001) and intensity (P = 0.001) between leiomyosarcomas and the other groups. There was no difference in p16 expression between usual leiomyomas, leiomyoma variants and STUMPs. There were also statistically significant differences in p53 (P = 0.014) and MIB1 (P < 0.001) immunoreactivity between leiomyosarcomas and the other groups.

CONCLUSIONS

p16 is overexpressed in uterine leiomyosarcomas compared with leiomyomas, benign leiomyoma variants and STUMPs, suggesting that p16 may be implicated in the pathogenesis of malignant uterine smooth muscle neoplasms. p16, in combination with p53 and MIB1, may be of value as an adjunct to morphological examination in the assessment of problematic uterine smooth muscle tumours, although further large-scale studies with follow-up are necessary to confirm this.

A new scoring system using multiple immunohistochemical markers for diagnosis of uterine smooth muscle tumors

The diagnosis of uterine smooth muscle neoplasms by light microscopy is difficult. Multiple classification schemes have been proposed based on mitotic rate, nuclear atypia, and the presence or absence of necrosis. None of these classification systems has been entirely successful. This study was undertaken to evaluate the use of selected immunohistochemical and histochemical markers in differentiating these tumors, in addition to accepted morphologic criteria. Ten cases of each of the following: leiomyosarcomas (LMS), atypical leiomyomas (AL), cellular leiomyomas (CL) and usual leiomyomas (UL), were classically evaluated for histological diagnosis and were stained for Ki-67 (MIB-1), bcl-2 and p53 using monoclonal antibodies and the avidin-biotin peroxidase method, and argyrophilic nucleolar organizer region (AgNORs). The number of stained cells was counted in the most positively stained region in a 4 mm² square cover glass mounted on each slide. The mean value was calculated for each group of tumors. The data for Ki-67 (MIB-1), bcl-2, p53 and AgNOR staining respectively, were significantly higher in LMS by comparison to UL, CL or AL. Because many singular cases had superimposed data being difficult to diagnose, a new scoring system for pathological evaluation was created. The results obtained by this scoring system suggest that immunohistochemical markers Ki-67 (MIB-1), bcl-2, p53 together with the AgNOR staining could be useful, by the scoring system, as an adjunct to the current accepted morphologic criteria in differentiating smooth muscle tumors of the uterus.

The expression of Ki-67, p53, estrogen and progesterone receptors affecting survival in uterine leiomyosarcomas. A clinicopathologic study

OBJECTIVES

To evaluate the level of expression of estrogen receptor (ER), progesterone receptor (PR), p53 and Ki-67 in patients with leiomyosarcoma and to investigate the effect of these and to identify the clinical parameters on prognosis.

MATERIALS AND METHODS

Twenty-four patients operated for LMS of uterine origin between 1994 and 2003 at Istanbul Medical School, Department of Obstetrics and Gynecology and Division of Gynecologic Oncology constituted our study group. The data of all patients were updated via mail or phone. The effects of stage, grade, chemotherapy, radiotherapy, number of mitoses, presence of necrosis, Ki-67 and p53 expression, presence of estrogen and progesterone receptors on survival were evaluated.

RESULTS

The mean follow-up period of patients is 30.42 +/- 25.15 months. The mean overall survival for all LMS patients was estimated to be 48.4 +/- 10.38 months. The cumulative survival ratio in the 33rd month was 33.08. Age, menopausal status, history of prior radiotherapy, number of mitoses had no statistically significant effect on overall survival in our study although stage had a significant effect. Finding of greater than 10% steroid receptor expression has a positive effect on survival ([ER P = 0.019; log rank = 5.49] and [PR P = 0.023; log rank = 5.14]). The median value of Ki-67 was calculated to be 30. There was a survival advantage in patients with Ki-67 expression (P = 0.034; log rank = 4.49) below the median value. p53 levels had no significant effect on survival (P = 0.336; log rank = 0.92).

CONCLUSION

Surgical staging is an important prognostic factor in LMS patients, while number of mitoses and grade of the tumor also seem to affect prognosis. Contrary to the current literature, our findings suggest that estrogen and progesterone receptor positivity greater than 10% may be associated with a better prognosis.

Massive myxoid leiomyosarcoma of the uterus

Uterine myxoid leiomyosarcoma is a very rare and aggressive variant of uterine sarcoma, of which only 26 cases have been described in the literature published in English. A 59-year-old woman, who had been menopausal for 5 years and had a huge abdominal mass underwent laparotomy; histopathology of the bulky tumor revealed the particular characteristics of a myxoid leiomyosarcoma. Immunohistochemically, Ki-67 contributed toward indicating a malignancy, whereas p53 and progesterone and estrogen receptors were negative. The level of serum Ca125 was high at diagnosis, within normal limits after the fifth cycle of chemotherapy, and subsequently increased again at recurrence. Sixteen months after surgery, the patient died of respiratory failure. Immunohistochemistry and Ca125 levels can aid the diagnosis, management, and prognosis of uterine myxoid leiomyosarcoma.

Differential Diagnosis of Smooth Muscle Tumors Utilizing p53, pTEN and Ki-67 Expression with Estrogen and Progesterone Receptors

BACKGROUND/AIM

To investigate the expression and value for diagnosis of the genes, p53 and pTEN, the protein, Ki-67, and the receptors, estrogen and progesterone, in differentiating smooth muscle tumors of the uterus.

MATERIAL AND METHOD

Seventeen samples of leiomyosarcoma, 2 smooth muscle tumors with uncertain malignant potential (STUMP), 9 atypical myomas and 15 leiomyomas were stained immunohistochemically. The chi(2) test was used for the statistical analysis of the data.

RESULTS

The malignant side of the spectrum was strongly stained for Ki-67 and p53 while uniformly decreasing toward the benign tumors. The results were found to be statistically significant (p < 0.0001). The staining for progesterone receptor was also statistically significant, but the tumors that were considered benign, such as leiomyoma and atypical myoma, were the ones strongly stained (p = 0.005). The expression of estrogen receptor was significant in these tumors, but the p value was very close to the cut-off value (p = 0.07). As the degree of differentiation of the tumor increased, the trend showed stronger staining for estrogen receptor. However, no difference was detected in the staining properties of the tumors for pTEN (p = 0.2457).

CONCLUSION

The expression of Ki-67, p53 and progesterone receptors is promising in immunodifferentiation of smooth muscle tumors of the uterus with malignant potential.

Myxoid leiomyosarcoma of the uterus with subsequent pregnancy and delivery

BACKGROUND

Myxoid leiomyosarcoma of the uterus is an extremely rare neoplasm. In young women with this disease, fertility should be considered in the treatment protocol.

CASE

A 20-year-old woman presented with a huge pelvic mass originating from the uterine wall and showing a histopathology of myxoid leiomyosarcoma. Five and one-half years after laparotomy, the recurrent tumor was found and removed. Two years after the second operation, she became pregnant, and delivered a healthy baby by cesarean section. Multiple recurrent masses were evident and removed at cesarean section. She is alive and well without evidence of recurrence 1 year after delivery.

CONCLUSION

The best treatment for this tumor is not established. In young women with a desire to bear children, the management is more controversial.

Oral leiomyosarcoma: review of the literature and report of two cases with assessment of the prognostic and diagnostic significance of immunohistochemical and molecular markers

Leiomyosarcoma of the oral cavity is a very rare tumor that is associated with aggressive clinical behavior and low survival. In this paper, we report two new cases of leiomyosarcoma affecting the mandibular gingiva and mandible of a 35-year-old male and the mandible of a 51-year-old female. Given the difficulty in the histopathologic discrimination between benign and malignant smooth muscle tumors and the absence of reliable histologic parameters for prognostication of leiomyosarcomas, we evaluated the diagnostic and prognostic value of various immunohistochemical and molecular markers. By means of immunohistochemistry and quantitative real-time PCR analysis, we detected protein expression of PCNA, bcl-2, CDK4, p53 and MDM2 in both our cases and MDM2 amplification in our second case. The literature, pertinent to oral leiomyosarcoma and to molecular analysis of smooth muscle tumors, is reviewed.

A huge abdominal mass mimicking ovarian cancer: p53-negative but aneuploid myxoid leiomyosarcoma of the uterus

OBJECTIVE

Less than 20 myxoid leiomyosarcoma cases were reported in literature. Since, these tumors are very rare and may exhibit highly malignant behavior despite their low mitotic index, clinical course and optimum type of therapy of myxoid variant of leiomyosarcoma were not well understood. The goal of this report is to contribute the better understanding of this rare type of tumor.

METHODS

A 39-year-old woman presented with a huge abdominal cystic mass. Laparotomy was performed and frozen section diagnosis was low-grade uterine leiomyosarcoma. TAH-BSO, omentectomy, pelvic lymph node and peritoneal samplings were carried out. No chemotherapy was performed after surgical therapy.

RESULTS

Final histopathological diagnosis was uterine myxoid leiomyosarcoma. The tumor was p53-negative and had aneuploid DNA content. The patient tolerated well the operation and she is alive and free of disease after 24 months of primary surgical treatment.

CONCLUSION

Uterine myxoid leiomyosarcoma may present a huge abdominal cystic mass and can be treated successfully with surgery alone.

Recent advances in the pathology of smooth muscle tumours of the uterus

Smooth muscle tumours of the uterus are common and the majority are benign leiomyomas. However, there are some tumours which exhibit unusual morphological features or growth patterns that cause difficulty in their distinction from malignant neoplasms and those with endometrial stromal differentiation. Such lesions are reviewed in this article with detailed descriptions of their morphology, differential diagnosis and correlation with biological behaviour.

MIB-1 (Ki-67), p53, estrogen receptor, and progesterone receptor expression in uterine smooth muscle tumors

The diagnosis of benign, uncertain malignant potential, and malignant uterine smooth muscle tumors depends on mitotic counts, nuclear atypia, and other morphologic features. This study was undertaken to evaluate the utility of selected immunohistochemical markers in differentiating these tumors. Fifteen cases of cellular leiomyoma, 7 cases of smooth muscle tumor of uncertain malignant potential (STUMP), and 12 cases of leiomyosarcoma were immunostained for MIB-1 (Ki-67), p53, estrogen receptor and progesterone receptor (PR) using monoclonal antibodies and the avidin-biotin-peroxidase method. The percentage of cells stained was subjectively assessed to the nearest 5%. One percent was used for rare positive cells. MIB-1 expression of > or =15% was seen in 11 and expression of p53 in > or =15% cells was present in 5 of 12 leiomyosarcomas. MIB-1 and/or p53 expression of >15% was seen in all 12 leiomyosarcomas but in none of the 7 STUMP or 15 cellular leiomyomas. PR was absent in 10 of 12 leiomyosarcomas but present in 7 of 7 STUMP and 14 of 15 cellular leiomyomas. MIB-1 of 5% to 10% was seen in 6 of 7 STUMP but in only 1 of 15 cellular leiomyomas. MIB-1, p53, and PR are useful in differentiating leiomyosarcoma from STUMP and cellular leiomyoma. MIB-1 is useful in distinguishing STUMP from cellular leiomyomas.

Involvement of cyclins in cell proliferation and their clinical implications in soft tissue smooth muscle tumors

Expression of cyclins A and E and cyclin-dependent kinase 2 (cdk2) was examined immunohistochemically in 55 cases of soft tissue smooth muscle tumors, including vascular leiomyoma, and compared to expression of Ki-67 and proliferating cell nuclear antigen. Cyclin A was expressed in 70% of the leiomyoma cases, but with much lower labeling indexes than in leiomyosarcoma. Cyclin E was expressed exclusively in leiomyosarcoma. Although the differences of cyclin A- and cyclin E-labeling indexes between leiomyoma and leiomyosarcoma were statistically significant, no significant differences were found in the other markers. Furthermore, cyclin A- and/or E-positivity predicted a poor prognosis in recurrence- or metastasis-free survivals and overall survival. Immunoblotting revealed that cyclins A and E were expressed, in complex with cdk2, exclusively in tumors. In addition, not only leiomyosarcoma, but also leiomyoma specimens that exhibited negligible levels of complex expression, manifested detectable cdk2 activity. These results suggest 1) up-regulation of active cyclin A/cdk2 expression and associated kinase activity is critical for unrestrained cell proliferation; 2) cyclin E/cdk2 complexes may play a crucial role in leiomyosarcoma; 3) immunohistochemical detection of cyclins can be a more reliable tool for differential diagnosis between leiomyoma versus leiomyosarcoma than that of Ki-67 or proliferating cell nuclear antigen, and be a possible prognostic indicator.

Uterine smooth muscle tumors: utility of classification by proliferation, ploidy, and prognostic markers versus traditional histopathology

CONTEXT

Accurate categorization of uterine smooth muscle neoplasms by light microscopic examination is difficult. Multiple classification schemes have been proposed based on mitotic rate, nuclear atypia, and the presence or absence of necrosis. None of these classification systems has been entirely successful. Multiple ancillary techniques have been tested for their ability to predict behavior of uterine smooth muscle tumors.

OBJECTIVE

We assayed 45 smooth muscle neoplasms for a variety of proliferation markers, oncogene protein products, and DNA ploidy level to determine if these markers supplied prognostically useful information over and above that obtained by routine light microscopic assessment.

STUDY DESIGN

Forty-five uterine smooth muscle neoplasms were assessed for DNA ploidy; silver-staining nucleolar organizer regions (AgNORs); percent nuclear proliferating cell nuclear antigen (PCNA); expression of p53, Her-2/neu, and MDM-2 protein; mitotic rate; and nuclear grade. These markers were correlated with histologic diagnosis and the occurrence of a clinically adverse event (death, metastasis, or recurrence).

RESULTS

Diagnostic category (P <.001), nuclear grade (P <.002), mitotic activity (P <.001), mean AgNORs (P <.001), percent nuclear PCNA (P =.02), and expression of p53 (P =.02) all correlated with clinical outcome. No statistically significant correlation between clinical outcome and the categories MDM-2 expression, Her-2/neu expression, or DNA ploidy was seen. Nuclear grade, p53 expression, mitotic rate, AgNORs, and percent nuclear PCNA correlated with diagnosis.

CONCLUSIONS

Diagnostic category, mitotic rate, AgNOR counts, PCNA, and p53 expression dichotomized uterine smooth muscle neoplasms into prognostically favorable and unfavorable groups. Although highly significant, the category AgNORs was no more successful than mitotic rate in dividing uterine smooth muscle neoplasms into prognostically favorable and unfavorable groups. Expression of p53 and percent nuclear PCNA dichotomized uterine smooth muscle neoplasms into prognostic groups, but neither technique reached the level of significance achieved by mitotic rate. Our data indicate that mitotic rate and the classification system of Kempson and Bari are at least as effective as the tested markers in separating uterine smooth muscle neoplasms into prognostic categories.

Primary hepatic leiomyosarcoma in a patient with hepatitis C virus-related liver cirrhosis

We describe an autopsy case of primary hepatic leiomyosarcoma in a 68-year-old man with hepatitis C virus-related liver cirrhosis. The patient, who had a history of acute hepatitis 20 years previously, died of a ruptured hepatic tumor. At autopsy, a well-circumscribed 14 x 16 x 15 cm tumor replaced the medial site of the right hepatic lobe with multiple intrahepatic and distant metastases. Histologically the tumor, which had extensive central necrosis, consisted predominantly of well or moderately differentiated spindle-shaped cells, which were positive for smooth muscle actin and vimentin on immunohistochemical staining. In addition, clusters of markedly atypical cells and myxoid change of the matrix were discretely found in the focal and small areas of the tumor. These findings indicated that many sections were necessary for the histologically accurate estimation of primary hepatic smooth muscle tumor. The histological examination of a non-tumorous lesion showed liver cirrhosis. Hepatitis C virus was detected in the cytoplasm of cirrhotic hepatocytes by immunohistochemistry and reverse transcriptase-polymerase chain reaction, but not in the tumor cells. This suggested that the virus was not directly involved in the development of primary hepatic leiomyosarcoma.

Possible role of calponin h1 as a tumor suppressor in human uterine leiomyosarcoma

BACKGROUND

Calponin h1, a basic actin-binding protein capable of inhibiting smooth muscle contraction, is a constitutive element of smooth muscle cells. However, in leiomyosarcoma (a type of smooth muscle neoplasm of the uterus), reduced expression of calponin h1 is observed, as we have reported previously. In this study, we sought to assess the effects (in vitro and in vivo) of increasing calponin h1 expression in leiomyosarcoma cells.

METHODS

A plasmid containing a human calponin h1 complementary DNA and a bacterial neomycin-resistance gene was transfected into the human leiomyosarcoma cell lines SKN and SK-LMS-1 by electroporation. Southern blotting, reverse transcription-polymerase chain reaction analysis, western blotting, and immunohistochemistry were used to confirm DNA transfer and expression of the calponin h1 protein in neomycin-resistant clones. We characterized the morphology of calponin h1-transfected cells, and we evaluated their proliferative activity and tumorigenicity by use of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, an anchorage-independent growth assay, and a nude mouse tumorigenicity assay.

RESULTS

The morphology of calponin h1-transfected cells in culture resembled that of cultured normal myometrial smooth muscle cells. With SK-LMS-1 cells, proliferation of calponin h1-transfection cells was reduced to 69% of control; with SKN cells, calponin h1 transfection reduced proliferation to 70% of control. In assays of anchorage-independent growth and in vivo tumorigenicity, both growth and tumorigenicity were statistically significantly reduced in calponin h1-transfected leiomyosarcoma cells.

CONCLUSIONS

Calponin h1 may function as a tumor suppressor in leiomyosarcoma. Clinically, transfer of a calponin h1 complementary DNA into poorly differentiated leiomyosarcoma cells may be of potential therapeutic value through induction of a normal, differentiated cellular phenotype.

Small intestinal stromal tumors: a clinicopathologic study of 31 tumors

The biologic behavior of gastrointestinal stromal tumors is difficult to predict, and they can be best studied in a site-specific fashion. The aims of this study are to analyze the clinicopathologic parameters and assess the prognostic value of p53 (DO-7) and Ki-67 (MIB-1) immunoreactivities in small intestinal stromal tumors (SIST). The histopathologic features of 31 SIST were assessed and categorized into two groups as follows. Group A (clinically aggressive) in which death due to tumor, metastasis, recurrence or relapsed melena were seen (n = 15) and group B (clinically benign; n = 16). For both groups, the period of follow-up was 30-144 months. p53 overexpression was observed in four tumors (31%) in group A, and in none in group B. For groups A and B, the mean Ki-67 index was 16.8 +/- 12.5 and 8.4 +/- 12.6, respectively. Statistical analysis revealed that the significant predictors of malignancy were high cellularity (odds ratio (OR) = 999; 95% confidence interval (CI) = 0-999); p53 overexpression (OR = 999; CI = 0-999); size of tumor > or = 5 cm (OR = 18.0; CI = 1.9-171.9); > or = 5 mitoses/50 high-power fields (HPF) (OR = 17.1; CI = 1.8-165.9); pleomorphism (OR = 17.1; CI = 1.8-165.9); and necrosis (OR = 11.9; CI = 2.2-65.1; P < 0.05). High Ki-67 index (> or = 8.4) had a marginal impact on risk (OR = 4.1; CI = 0.8-20.2; P = 0.08). In conclusion, high cellularity, p53 overexpression, size of tumor > or = 5 cm, > or = 5 mitoses/50 HPF, pleomorphism and necrosis are important parameters for the prediction of malignancy in SIST.

[Myxoid leiomyosarcoma of the esophagus]

A 34-year-old male patient with epigastralgia was found to have an esophageal submucosal tumor based on an endoscopic evaluation 6 years previously. Because an unusual appearance composed of a heterogeneous solid area and a cyst area on the endoscopic ultrasonogram and the increased size of the tumor on esophagograms over the past 3 years were suggestive of a malignant character, an operation was thus indicated. The tumor, which measured 3.5 x 2.5 x 2.0 cm in size, was enucleated using videoassisted thoracic surgery and was diagnosed to be a very rare myxoid leiomyosarcoma with a thorough pathologic examination. To our knowledge, this is only the second case of esophageal myxoid leiomyosarcoma reported in the literature. We thus consider this case, which demonstrated an unique appearance on an endoscopic ultrasonogram, to possibly be beneficial to the overall diagnostic analysis of esophageal submucosal tumors.