Cerebellar Differentiation in Ovarian Teratoma: A Report of 6 Cases.

Ovarian teratomas potentially demonstrate a wide range of tissue elements including central nervous system differentiation. The latter can include cerebellar tissue, which in our experience remains an under-recognized phenomenon. In the current study we present a review of 6 ovarian teratomas including 4 mature cystic teratomas and 2 immature teratomas showing cerebellar differentiation. Two cases were seen in consultation because the cerebellar elements were initially misinterpreted as immature teratomas. Two mature cystic teratomas focally demonstrated a distinct cerebellar architecture including folial type structures, but in all cases the cerebellar elements usually showed a less organized anatomic appearance, and sometimes these were concerning for immature teratomas upon initial examination. This concern was exacerbated in 5 cases by the presence of a cytologically immature and mitotically active neuronal component corresponding to the external granular layer of normal fetal and neonatal cerebellum. However, careful examination demonstrated the characteristic molecular, Purkinje and (internal) granular layers of cerebellum. Furthermore, while the external granular layer in teratomas strongly expressed Ki67, corresponding to the proliferative activity of this cellular compartment physiologically, immunostaining was often helpful in highlighting the preserved zonal pattern of cellular proliferation. The absence or minimal expression of SALL4, OCT3/4, and SOX2 was also helpful in this regard. Cytoplasmic OCT3/4 expression in osteoblasts was noted incidentally in 2 tumors, but further studies are required to determine whether this is a consistent and diagnostically useful finding.

Podoplanin and SOX2 Expression in CIN 3-like Squamous Cell Carcinoma of the Cervix.

Squamous cell carcinoma (SCC) of the uterine cervix occasionally demonstrates a deceptive growth pattern that mimics endocervical crypt involvement by cervical intraepithelial neoplasia, grade 3 (CIN 3). Such CIN 3-like SCCs may be misinterpreted as noninvasive or minimally invasive leading to delays in diagnosis. Little is known of the factors that influence the growth patterns of cervical SCC but we suggested recently that CIN 3-like tumors might demonstrate "collective cellular invasion," which is characterized by a retained epithelial phenotype. This contrasts with the more overtly infiltrative growth of conventional SCC, which exhibits features suggestive of epithelial-mesenchymal transition. In the current study we investigated podoplanin (PP) and SOX2 expression in normal squamous epithelium, in CIN 3 and in 16 CIN 3-like SCCs 11 of which also showed a conventional invasive component. Compared with normal epithelium, CIN 3 often showed a focal loss of basal PP staining and most cases showed increased, typically diffuse, SOX2 expression. Although the immunohistochemical findings were not uniform, they generally supported collective cellular invasion in CIN 3-like tumor areas as these were often PP positive and showed diffuse SOX2 expression. In contrast, most conventional SCCs showed only focal SOX2 staining and they were typically negative, or only focally positive, for PP. The staining patterns did not reliably distinguish CIN 3 from CIN 3-like SCC. Small infiltrative tumor nests around the margins of CIN 3 or deeply invasive CIN 3-like SCC often showed a localized reduction in SOX2 expression suggesting SOX2 downregulation during the transition to invasive growth.

Cervical intraepithelial neoplasia (CIN) 3-like squamous cell carcinoma of the cervix: a review of 14 cases with comparison of E-cadherin and cyclin D1 expression in the CIN 3-like and infiltrative tumour elements.

AIMS: To review the clinicopathological features of 14 cases of CIN 3-like squamous cell carcinoma (SCC) of the cervix and to investigate possible mechanisms of tumour invasion in the CIN 3-like and 'conventional' (infiltrative) tumour components. METHODS AND RESULTS: The median patient age was 43.4 years. Of the 12 cases with known stage, eight were stage IB and four were stage II. Initial biopsies were often misinterpreted as CIN 3 alone or CIN 3 with only superficial stromal invasion, and eight patients underwent multiple biopsy procedures prior to definitive diagnosis: upon review, an earlier diagnosis was possible in six of these cases. Nine tumours exhibited both CIN 3-like and conventional tumour components. The former usually demonstrated an E-cadherin-positive and cyclin D1-negative immunophenotype, whereas conventional SCC more often showed loss of E-cadherin and cyclin D1 staining at the margin of larger tumour nests and in smaller invasive clusters. CONCLUSION: Cervical SCCs demonstrating a CIN 3-like growth pattern continue to present diagnostic difficulty and are often misinterpreted as non-invasive/minimally invasive disease. The morphology and immunophenotype suggest a process of collective cellular invasion in CIN 3-like SCC, whereas corresponding conventional SCC elements show features consistent with epithelial-mesenchymal transition.

Histological comparison of partial hydatidiform mole and trisomy gestation specimens.

The distinction between partial hydatidiform mole (PHM) and trisomy gestation is not always straightforward histologically and it is unclear which morphological features, alone or in combination, provide the greatest diagnostic accuracy. We performed a comparative review of 89 products of conception (POC) specimens including 54 PHMs and 35 trisomy gestations, assessing the following in each case: trophoblastic atypia, cistern formation, multifocal trophoblast proliferation, lace-like trophoblast, villous enlargement, large trophoblast inclusions, scalloped villous shape, stromal apoptosis, small round villous inclusions, and fibrillary stromal collagen. There was a significant difference in the presence of trophoblast atypia, cistern formation, multifocal trophoblast proliferation, lace-like trophoblast, large trophoblastic inclusions, small round villous inclusions, fibrillary collagen (all p<0.01), and apoptosis (p=0.028), between PHM and trisomy cases. Fibrillary collagen was more common in trisomy specimens whereas the other features were more common in PHMs. There was no significant difference in villous enlargement or scalloped villous shape between the two groups. The combination of cistern formation, multifocal trophoblast proliferation and large trophoblast inclusions correctly classified 83 (93.3%) of cases where the presence of at least two features was considered diagnostic of PHM. While cytogenetic analysis is arguably the gold standard for diagnosis, this study demonstrates that histological assessment permits accurate distinction of PHM and trisomic gestations in the great majority of cases.

Fascin expression in undifferentiated and dedifferentiated endometrial carcinoma.

The actin-binding protein fascin promotes cellular invasion, and increased fascin expression correlates with adverse prognostic factors in a variety of tumors. Fascin up-regulation may also be associated with epithelial-mesenchymal transition in neoplastic epithelial cells. This study investigated fascin expression in undifferentiated and dedifferentiated endometrial carcinoma (UEC), a clinically aggressive variant of endometrial neoplasia. Twenty-two UECs, 5 of which were entirely undifferentiated and 17 dedifferentiated, were examined. In the dedifferentiated group, staining was compared between the differentiated and undifferentiated tumor components. Where applicable, fascin expression was noted in foci of lymphovascular space invasion. The mean age was 67.6 years, and 11 patients (50%) presented with stage III or IV disease. The undifferentiated tumor component showed diffuse fascin expression in 20 cases (91%) including 4 of 5 pure undifferentiated carcinomas and 16 of 17 dedifferentiated carcinomas. In contrast, the low-grade endometrioid carcinoma component of 13 (77%) of 17 dedifferentiated carcinomas was fascin negative or showed only focal staining. Intravascular undifferentiated tumor cells were identified in 16 cases, and these were consistently fascin positive, whereas low-grade intravascular tumor cells, present in 2 cases, were not stained. Fascin up-regulation may be a contributory factor toward the highly invasive character of UEC and could represent an epithelial-mesenchymal transition-like process in these tumors. Fascin expression in intravascular tumor cells may be permissive toward intravascular survival and metastatic risk.

SWI/SNF complex deficiency and mismatch repair protein expression in undifferentiated and dedifferentiated endometrial carcinoma.

Undifferentiated endometrial carcinoma (UEC) is a relatively uncommon but clinically aggressive uterine malignancy. In common with a subset of poorly differentiated carcinomas arising in other sites, UEC may exhibit rhabdoid morphology and be associated with a low-grade tumour component (dedifferentiated carcinoma). Recent studies have implicated inactivation of the SWI/SNF complex subunits in the aforementioned extrauterine tumours. Therefore we have examined INI1 (SMARCB1), BRG1 (SMARCA4), and BAF250a (ARID1A) immunostaining, and also expression of the DNA mismatch repair (MMR) proteins MLH1, PMS2, MSH2 and MSH6 in 22 UEC, seventeen of which were dedifferentiated. Abnormal SWI/SNF subunit expression was detected in four dedifferentiated carcinomas including three with loss of BRG1 staining limited to the undifferentiated tumour component and one case with loss of INI1 expression in both low- and high-grade elements; the latter case also showed BAF250a deficiency in the undifferentiated tumour cells. Abnormal MMR protein expression was identified in 13 tumours (59%) including nine with concurrent loss of MLH1 and PMS2. These findings suggest that SWI/SNF subunit alterations may play a role in the progression/ dedifferentiation of endometrial carcinoma, and that SWI/SNF and MMR protein deficiencies may act synergistically in deregulating DNA repair mechanisms in these tumours.

PAX2 and cyclin D1 expression in the distinction between cervical microglandular hyperplasia and endometrial microglandular-like carcinoma: a comparison with p16, vimentin, and Ki67.

Microglandular hyperplasia (MGH) is a common endocervical alteration that in most cases presents no diagnostic difficulty. However, MGH rarely shows atypical features that may mimic endocervical neoplasia, while conversely endometrial carcinomas can show deceptively bland MGH-like appearances. It has been suggested that immunohistochemical analysis is useful in this context, but relatively few studies have specifically investigated microglandular pattern lesions and the results have been conflicting. In this study, we have examined a series of MGH (n=24), atypical MGH (n=2), and endometrial microglandular-like carcinomas (EMC, n=8), with a panel of antibodies including PAX2, cyclin D1, p16, vimentin, and Ki67. Loss of PAX2 staining was identified only in EMC but had relatively poor sensitivity for a malignant diagnosis (3/8 cases). Seven EMCs showed p16 expression and staining was diffuse (≥50% cells) in 6 cases, whereas all conventional MGH lesions were negative. However, 1 case of atypical MGH was also p16-positive. Cyclin D1, vimentin, and Ki67 did not reliably distinguish the benign and malignant microglandular lesions because of considerable overlap in staining patterns. In summary, none of the antibodies examined proved completely sensitive and specific, but a p16-positive/PAX2-negative phenotype favored a diagnosis of EMC. Pathologists should be aware that EMC, like some other types of endometrial carcinoma, are commonly p16-positive to avoid misinterpretation as a primary endocervical neoplasm. In practice, correlation of the histologic, immunohistologic, and clinical findings is necessary for accurate interpretation of microgandular-pattern lesions, particularly in small biopsy samples.

Extravascular migratory metastasis in gynaecological carcinosarcoma.

AIMS: Extravascular migratory metastasis (EVMM) is a potential mechanism of tumour spread reported most extensively in cutaneous melanoma. It has not been described previously in gynaecological malignancies. We describe EVMM in four gynaecological carcinosarcomas. METHODS AND RESULTS: Extravascular migratory metastasis was observed in an ovarian carcinosarcoma during routine diagnostic assessment. Twenty-three additional, randomly selected gynaecological carcinosarcomas (11 tubo-ovarian and 12 endometrial) were examined retrospectively and EVMM was identified in three of these. Other than the index case, EVMM was a focal finding, identified in 12-18% of slides. The malignant cells demonstrating EVMM appeared sarcomatoid and were distributed abluminally, partly or completely surrounding the endothelium. Affected vessels often showed mural fibrin deposition. Immunohistochemistry for α-smooth muscle actin (SMA), CD31, CD34, D2-40, laminin and type IV collagen was performed on the EVMM-positive cases. The perivascular malignant cells showed more consistent SMA and laminin immunoreactivity than the non-vascular tumour elements. CONCLUSIONS: Extravascular migratory metastasis is a hitherto unrecognized mechanism of tumour spread in gynaecological carcinosarcomas. The perivascular tumour cells appear to adopt a pericytic phenotype, and this may represent a specific pattern of epithelial-mesenchymal transition. Further studies with pericyte-specific immunohistological markers may better demonstrate the presence and possible prognostic significance of EVMM in gynaecological tumours.

An immunohistochemical and molecular analysis of problematic and unclassified ovarian sex cord-stromal tumors.

Most ovarian sex cord-stromal tumors (SCSTs) can be categorized on the basis of conventional histology, but approximately 10% of cases are unclassified because they present indeterminate or overlapping morphologic features. Immunohistochemical and molecular studies of unclassified ovarian SCST are very limited, but recently, it has been demonstrated that 2 major subgroups of SCST, adult-type granulosa cell tumor and Sertoli-Leydig cell tumor, are characterized by somatic mutations in FOXL2 and DICER1, respectively. In this study, 12 diagnostically problematic ovarian SCST, including 9 unclassified tumors, were investigated for FOXL2 and DICER1 mutations and for immunohistochemical expression of calretinin, CD56, CD99, estrogen receptor α, estrogen receptor ß, FOXL2, inhibin, progesterone receptor, and steroidogenic factor-1. Four of 11 tumors with satisfactory analysis showed a FOXL2 mutation; 3 of these cases were reported initially as unclassified SCST and 1 as Sertoli-Leydig cell tumor. Conversely, 3 cases with an original diagnosis of granulosa cell tumor were FOXL2 mutation-negative, and none of 7 tumors with satisfactory analysis demonstrated a DICER1 mutation. All tumors expressed at least 4 of the immunomarkers examined, although staining was often focal and there was no consistent correlation with tumor morphology. In conclusion, molecular analysis is useful in the assessment of diagnostically challenging ovarian SCST. The absence of FOXL2 and DICER1 mutations in most unclassified SCST suggests that these could represent a distinct tumor subgroup with different molecular pathogenesis. Immunohistochemical profiles overlap with those of better categorized SCST, but staining may be focal or negative emphasizing the requirement for antibody panels in diagnostic assessment.

Immunophenotypic analysis of ovarian endometrioid adenocarcinoma: correlation with KRAS mutation and the presence of endometriosis.

AIMS: The relationship between endometriosis and ovarian endometrioid adenocarcinoma (OEC) is well recognised but it is unclear whether endometriosis positive and negative OECs develop via similar pathogenetic mechanisms. MATERIALS: Sixty-seven low grade OECs (35 associated with endometriosis) were stained immunohistochemically for ß-catenin, cyclin D1, BAF250a, PTEN, p53, WT1 and the mismatch repair (MMR) proteins MLH1, PMS2, MSH2 and MSH6. The results were correlated with KRAS mutation analysis and the presence of concurrent endometriosis. RESULTS: Abnormal ß-catenin, cyclin D1, BAF250a, PTEN, p53 and MMR protein expression was identified in 61.2%, 50.7%, 19.4%, 23.9%, 9.0%, and 6.0% of cases, respectively; these changes were equally common in endometriosis positive and negative tumours. WT1 expression was restricted to endometriosis negative EOC (8/32, 25%) and four WT1 positive cases showed sertoliform/spindle cell histological patterns. Abnormal ß-catenin expression correlated with cyclin D1 overexpression but was inversely related to KRAS mutation. Immunophenotypic abnormalities were present in four of 17 histologically benign endometriotic lesions. CONCLUSIONS: Most immunophenotypic alterations were equally common in endometriosis associated and independent OECs but only the latter were associated with abnormal WT1 expression. The inverse relationship between abnormal ß-catenin expression and KRAS mutation merits further study. Histologically benign endometriotic epithelium may show immunophenotypic abnormalities similar to those present in associated carcinomas.

Changes in thymic regulatory T-cell maturation from birth to puberty: differences in atopic children.

BACKGROUND: Characterization of regulatory immune pathways is a research priority for both the pathogenesis of allergic disease and potential therapeutic strategies. OBJECTIVE: The thymus is a rich source of regulatory T (Treg) cells, which offers a novel opportunity to document the maturation of these pathways beyond limited studies on small volumes of peripheral blood available from young children. METHODS: Thymus tissue was collected from children undergoing cardiac surgery (age, 1 week to 14 years), and skin prick testing was performed from 12 months of age. The ontogeny of Treg cell maturation and function was examined in atopic (n = 20) and nonatopic (n = 20) children by assessing their phenotype, enumeration, proliferation, and suppressive ability. RESULTS: Age-related changes in the thymic cytokine milieu paralleled the changes seen in peripheral immune function. Specifically, the thymic microenvironment is similarly T(H)2 skewed during the early postnatal period, and this undergoes age-related suppression as the T(H)1 (IFN-γ) response increased. We detected CD4(+)CD25(+)CD127(lo/-) forkhead box protein 3 (FOXP3)-positive Treg cells in the neonatal thymus. These cells suppressed the proliferative response to allogeneic stimulation of CD4(+)CD25(-) T cells dose dependently. In nonatopic children Treg cell turnover and suppressive function increased with age and paralleled the increase in global thymic FOXP3 mRNA expression, whereas in atopic children Treg cell maturation was significantly delayed compared with that seen in age-matched nonatopic children. CONCLUSION: These data suggest that the developmental changes in the thymus parallel the recognized changes in peripheral blood responses. There is also a developmental delay in the function of thymic regulatory cells in atopic compared with nonatopic children. These differences are fundamental to understanding early events that lead to immune dysregulation and might predispose to allergic disease.

Cytokeratin 19 expression in normal endometrium and in low-grade endometrioid adenocarcinoma of the endometrium.

The low-molecular-weight cytokeratin (CK) protein CK19 has been shown to have diagnostic use and prognostic significance in some types of human malignancy, but little is known of its distribution in normal endometrial mucosa or in endometrial endometrioid adenocarcinoma. However, we had observed that CK19 appeared to selectively label invasive tumor areas showing microcystic, elongated, and fragmented ("MELF") changes. Therefore, CK19 expression was assessed in 15 hysterectomy specimens showing normal proliferative, secretory, or atrophic endometrial appearances, and in 26 endometrioid adenocarcinoma cases with areas of MELF-type invasion. Normal endometrial glands were usually CK19 positive; however, there was more consistent expression in the functional layer, whereas basal zone epithelium was typically only focally stained. Proliferative epithelium frequently showed basal and apical cytoplasmic accentuation of staining. Endometrial carcinomas were also CK19 positive, but in most cases there was a distinct zonal pattern of expression with strong staining only in the central aspects of the larger tumor glands and weak-to-absent staining in peripheral glandular areas. In contrast, MELF-type tumor epithelium was consistently and strongly CK19 positive even when the adjacent "conventional"-type tumor glands were not stained. Intravascular tumor cells were also highlighted, including 2 cases in which this feature was not identified on hematoxylin and eosin stains. Thus CK19 immunohistochemistry was useful in showing the extent of myometrial invasion and subtle foci of lympho-vascular space invasion. Further studies are required to determine the mechanism and biologic significance of localized alterations in CK19 expression within endometrial neoplasms.

Fascin expression in low-grade uterine endometrioid adenocarcinoma: correlation with microcystic, elongated and fragmented (MELF)-type alteration at the deep invasive margin.

AIMS: The actin-binding protein fascin appears to potentiate the migratory capacity of both normal and neoplastic cells. It has been suggested that microcystic, elongated and fragmented (MELF) glands might represent areas of active invasion within uterine low-grade endometrioid adenocarcinomas. Therefore, fascin immunoreactivity was investigated in a series of endometrial carcinomas specifically comparing expression in conventional tumour areas, foci of MELF-type invasion and in stromal elements. METHODS AND RESULTS: Fascin expression was assessed in 28 uterine endometrioid adenocarcinomas and the results compared with cytokeratin (CK) 7 expression and with tumour morphology and distribution. The conventional glandular component of most tumours showed only focal fascin reactivity (<10% cells positive), but staining was more prominent within the peripheral epithelial cells. Foci of squamous/morular type differentiation were also positive. The neoplastic epithelium in MELF-type invasion usually showed strong fascin immunoreactivity, often contrasting with the adjacent negative or more weakly stained conventional tumour glands. There was also staining of reactive stromal cells surrounding MELF foci. CONCLUSIONS: There are distinct micro-anatomical variations in fascin immunoreactivity within endometrial carcinoma. The localized increase in fascin expression in MELF-type epithelium supports the proposal that MELF changes represent areas of active tumour invasion.

Correlation between invasive pattern and immunophenotypic alterations in endocervical adenocarcinoma.

AIMS: To assess the immunophenotypic changes associated with epithelial-mesenchymal transition (EMT) in endocervical adenocarcinoma, and correlate the findings with tumour morphology including growth pattern. METHODS AND RESULTS: Twenty-seven endocervical adenocarcinomas were studied using a panel of immunohistochemical markers to vimentin, cyclin D1, E-cadherin, beta-catenin, p16 protein and cytokeratin 7. There were 24 moderately differentiated and three poorly differentiated tumours. Fourteen of the moderately differentiated carcinomas showed a focal infiltrative component, typically towards the deep tumour margin (invasive front), comprising attenuated glands, small cell clusters and single cells. These foci typically showed cytological alteration including loss of cellular polarity and cytoplasmic eosinophilia, while immunohistochemistry demonstrated reduced cell membrane E-cadherin and beta catenin labelling, and expression of cyclin D1 and, in some cases, vimentin. Similar immunophenotypic changes were focally observed at the deep aspect of some larger 'conventional' tumour glands. No consistent changes were observed in the poorly differentiated carcinomas. CONCLUSIONS: Endocervical adenocarcinomas that demonstrate an infiltrative growth pattern show immunophenotypic changes consistent with EMT. Frequently, these are accompanied by a morphological alteration in the tumour cells and the changes exhibit a specific micro-anatomical distribution. Epithelial-mesenchymal transition may represent an important mechanism in the progression of some endocervical neoplasms.

Galectin-3 expression in uterine endometrioid adenocarcinoma: comparison of staining in conventional tumor glands and in areas of MELF pattern myometrial invasion.

Endometrioid adenocarcinoma (EAC) of the uterus can show varying patterns of invasion, 1 of which, "MELF," is characterized by the presence of microcystic, elongated, and fragmented glands. However, at present, little is known of the functional alterations in neoplastic cells that are associated with the different patterns of myometrial invasion, including those in MELF. Galectin-3 is a widely distributed and multifunctional carbohydrate binding protein that has been shown to influence many aspects of tumor development and progression, but there are limited and conflicting data regarding galectin-3 expression in EAC. In this study, galectin-3 immunoreactivity was investigated in 22 EACs with specific comparison of staining in the "conventional" endometrioid-type tumor glands and in areas exhibiting MELF pattern invasion. Cytoplasmic galectin-3 was present in all tumors although <50% of cells were stained in approximately one-third of the cases. Nuclear staining was evident in 11 cases, but usually only in a small proportion of cells. The neoplastic epithelium within MELF areas showed a consistent reduction in protein expression, often contrasting with the adjacent galectin-3-positive conventional glands and reactive stromal cells. Conversely, intravascular tumor foci often showed cytoplasmic and nuclear galectin-3 immunoreactivity. The microanatomical variation in galectin-3 expression in EAC suggests that there are localized functional alterations in the neoplastic epithelium and the surrounding stroma during the invasive process. As MELF pattern invasion is associated with the loss of galectin-3 expression, there may be implications for the use of galectin inhibitors in the treatment of endometrial carcinomas and other malignancies.

Micro-anatomical variation in cellular proliferation in endometrial adenocarcinoma, and inverse correlation between Ki67 and cytokeratin 7 expression.

AIMS: To investigate micro-anatomical variations in proliferative activity within uterine endometrioid adenocarcinoma with particular emphasis on tumour areas comprising microcystic, elongated and fragmented ('MELF') glands. METHODS AND RESULTS: Ki67 immunoreactivity was assessed in 29 low-grade endometrial adenocarcinomas specifically comparing conventional tumour glands and areas exhibiting MELF-type alteration. Furthermore, since Ki67 expression differed between the peripheral and central aspects of larger neoplastic glands, these micro-anatomical compartments were assessed separately using a semiquantitative scoring system. Most MELF-type tumour elements were negative for Ki67 or showed only rare (< 5% cells) positivity. In contrast, peripheral conventional tumour glands showed prominent Ki67 labelling, but this was significantly reduced in central glandular areas. An inverse correlation between Ki67 and cytokeratin (CK) 7 expression was noted in many tumours. CONCLUSIONS: Endometrial adenocarcinomas show micro-anatomical variations in Ki67 expression and this is often inversely correlated with CK7 immunoreactivity. MELF-type tumour elements show minimal proliferative activity, a finding that initially appears unexpected for areas of purported active invasion. However, an inverse correlation between cell division and local invasion has been demonstrated in other malignancies, notably during epithelial-mesenchymal transition, and this may reflect a reversible alteration in cellular activity during neoplastic progression.

Comparison of proliferation indices in primary adult-type granulosa cell tumors of the ovary and their corresponding metastases: an analysis of 14 cases.

Adult-type granulosa cell tumors (GCTs) of the ovary are generally low-grade malignancies, but late metastases are relatively common. Limited data suggest that recurrent GCTs may exhibit altered morphology and/or biologic behavior, but few studies have directly compared primary and recurrent tumors in individual patients. Fourteen GCTs in which histologic material was available from both the primary tumor and one or more metastases were reviewed, and the mitotic index (MI) and Ki-67 labelling index (KI) were evaluated using carefully specified methodology. The findings were also correlated with the time interval to tumor recurrence. The median interval to first recurrence was 6.6 years (range: 2.2 to 12.2 yr). There were only minor differences in tumor morphology between the primary and metastatic GCTs. None of the cases exhibited high-grade (sarcomatoid) transformation. There was a wide range in MI and KI in the GCTs and no consistent correlation was seen between these indices in the paired primary and recurrent neoplasms. There was also no association between the MI and the KI and the time interval to metastasis. In conclusion, metastatic GCTs generally maintain their morphologic features even after multiple recurrences over many years. Cellular proliferation in GCT is variable, and there is no uniform alteration in proliferation indices between paired primary and metastatic lesions. Therefore, data derived from the analysis of primary GCT may not always be applicable to recurrent tumors. These findings may have implications for management including the potential response of GCT to adjuvant therapies.

Expression of cell cycle regulatory proteins in endometrial adenocarcinoma: variations in conventional tumor areas and in microcystic, elongated and fragmented glands.

Endometrial adenocarcinomas may show a distinctive pattern of invasion characterized by the presence of microcystic, elongated and fragmented glands, often most evident along the advancing tumor margin. Earlier, we have shown that these changes appear restricted to low-grade endometrioid carcinomas, many of which show focal mucinous differentiation and lymphovascular space invasion. However, the molecular alterations associated with this morphological alteration are not known. In this study, we have examined immunoreactivity for the cell cycle regulatory proteins cyclin D1, p16 and beta-catenin in 22 endometrial carcinomas, specifically comparing the results in conventional tumor areas and in foci in which the glands exhibited microcystic, elongated and fragmented appearances. The conventional neoplastic glands exhibited cyclin D1 and p16 expression in most cases, with >50% tumor cells positive in 8 cases and 11 tumors, respectively. Membranous expression of beta-catenin was usually preserved, with variable cytoplasmic and nuclear staining. Cyclin D1 and beta-catenin predominantly stained cells at the peripheral or basal aspect of the conventional glands, whereas p16 was more uniformly expressed centrally. Tumor foci composed of microcystic, fragmented and elongated glands showed strong expression of cyclin D1 and p16, sometimes in contrast to unstained contiguous or adjacent conventional neoplastic elements, and there was also loss or fragmentation of membranous beta-catenin staining. Intravascular tumor cells also expressed cyclin D1 and p16 and therefore the immunostains often highlighted subtle foci of lymphovascular invasion. The heterogeneous expression of cell cycle regulatory proteins within endometrial adenocarcinoma illustrates the importance of assessing microanatomical variations in immunoreactivity, particularly at the advancing margin of tumors. The upregulation of cyclin D1 and p16, together with loss of membranous beta-catenin expression in microcystic, fragmented and elongated glands, is similar to epithelial-mesenchymal transitions observed in other malignancies and suggests that this pattern of invasion represents an active rather than a degenerative cellular process.