Combined hepatocellular-cholangiocarcinoma: An update on epidemiology, classification, diagnosis and management.

BACKGROUND: Combined hepatocellular-cholangiocarcinoma (CHC) is a rare subtype of primary hepatic malignancies, with variably reported incidence between 0.4%-14.2% of primary liver cancer cases. This study aimed to systematically review the epidemiological, clinicopathological, diagnostic and therapeutic data for this rare entity. DATA SOURCES: We reviewed the literature of diagnostic approach of CHC with special reference to its clinical, molecular and histopathological characteristics. Additional analysis of the recent literature in order to evaluate the results of surgical and systemic treatment of this entity has been accomplished. RESULTS: The median age at CHC's diagnosis appears to be between 50 and 75 years. Evaluation of tumor markers [alpha fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA)] along with imaging patterns provides better opportunities for CHC's preoperative diagnosis. Reported clinicopathologic prognostic parameters possibly correlated with increased tumor recurrence and grimmer survival odds include advanced age, tumor size, nodal and distal metastases, vascular and regional organ invasion, multifocality, decreased capsule formation, stem-cell features verification and increased GGT as well as CA19-9 and CEA levels. In case of inoperable or recurrent disease, combinations of cholangiocarcinoma-directed systemic agents display superior results over sorafenib. Liver-directed methods, such as transarterial chemoembolization (TACE), percutaneous ethanol injection (PEI), hepatic arterial infusion chemotherapy (HAIC), radioembolization and ablative therapies, demonstrate inferior efficacy than in cases of hepatocellular carcinoma (HCC) due to CHC's common hypovascularity. CONCLUSIONS: CHC demonstrates an overlapping clinical and biological pattern between its malignant ingredients. Natural history of the disease seems to be determined by the predominant tumor element. Gold standard for diagnosis is histology of surgical specimens. Regarding therapeutic interventions, major hepatectomy is acknowledged as the cornerstone of treatment whereas minor hepatectomy and liver transplantation may be applied in patients with advanced cirrhosis. Despite all therapeutic attempts, prognosis of CHC remains dismal.

Genomic and Transcriptomic Profiling of Combined Hepatocellular and Intrahepatic Cholangiocarcinoma Reveals Distinct Molecular Subtypes.

We performed genomic and transcriptomic sequencing of 133 combined hepatocellular and intrahepatic cholangiocarcinoma (cHCC-ICC) cases, including separate, combined, and mixed subtypes. Integrative comparison of cHCC-ICC with hepatocellular carcinoma and intrahepatic cholangiocarcinoma revealed that combined and mixed type cHCC-ICCs are distinct subtypes with different clinical and molecular features. Integrating laser microdissection, cancer cell fraction analysis, and single nucleus sequencing, we revealed both mono- and multiclonal origins in the separate type cHCC-ICCs, whereas combined and mixed type cHCC-ICCs were all monoclonal origin. Notably, cHCC-ICCs showed significantly higher expression of Nestin, suggesting Nestin may serve as a biomarker for diagnosing cHCC-ICC. Our results provide important biological and clinical insights into cHCC-ICC.

Phenotypic and molecular dissection of metaplastic breast cancer and the prognostic implications.

Metaplastic breast carcinoma (MBC) is relatively rare but accounts for a significant proportion of global breast cancer mortality. This group is extremely heterogeneous and by definition exhibits metaplastic change to squamous and/or mesenchymal elements, including spindle, squamous, chondroid, osseous, and rhabdomyoid features. Clinically, patients are more likely to present with large primary tumours (higher stage), distant metastases, and overall, have shorter 5-year survival compared to invasive carcinomas of no special type. The current World Health Organisation (WHO) diagnostic classification for this cancer type is based purely on morphology - the biological basis and clinical relevance of its seven sub-categories are currently unclear. By establishing the Asia-Pacific MBC (AP-MBC) Consortium, we amassed a large series of MBCs (n = 347) and analysed the mutation profile of a subset, expression of 14 breast cancer biomarkers, and clinicopathological correlates, contextualising our findings within the WHO guidelines. The most significant indicators of poor prognosis were large tumour size (T3; p = 0.004), loss of cytokeratin expression (lack of staining with pan-cytokeratin AE1/3 antibody; p = 0.007), EGFR overexpression (p = 0.01), and for 'mixed' MBC, the presence of more than three distinct morphological entities (p = 0.007). Conversely, fewer morphological components and EGFR negativity were favourable indicators. Exome sequencing of 30 cases confirmed enrichment of TP53 and PTEN mutations, and intriguingly, concurrent mutations of TP53, PTEN, and PIK3CA. Mutations in neurofibromatosis-1 (NF1) were also overrepresented [16.7% MBCs compared to ∼5% of breast cancers overall; enrichment p = 0.028; mutation significance p = 0.006 (OncodriveFM)], consistent with published case reports implicating germline NF1 mutations in MBC risk. Taken together, we propose a practically minor but clinically significant modification to the guidelines: all WHO_1 mixed-type tumours should have the number of morphologies present recorded, as a mechanism for refining prognosis, and that EGFR and pan-cytokeratin expression are important prognostic markers. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Renal cell carcinoma, unclassified with medullary phenotype: poorly differentiated adenocarcinomas overlapping with renal medullary carcinoma.

Renal medullary carcinoma (RMC) is a highly aggressive renal cell carcinoma arising in the collecting system and requiring careful correlation with status of sickle cell trait. A panel of international experts has recently proposed provisional diagnostic terminology, renal cell carcinoma, unclassified, with medullary phenotype, based on encountering an extraordinarily rare tumor with RMC morphology and immunophenotype in an individual proven not to have a hemoglobinopathy. Herein, we extend this observation to a cohort of 5 such tumors, morphologically similar to RMC, lacking SMARCB1 expression by immunohistochemistry, but each without evidence of a hemoglobinopathy. The tumors arose in 4 men and 1 woman with a mean age of 44 years, occurring in 3 left and 2 right kidneys. Clinically, aggression was apparent with involvement of perinephric adipose tissue in all 5 cases, nodal metastasis in 4 of 5 cases, and death of disease in 4 of 5 cases within 3-27 months. Histologic sections showed poorly differentiated adenocarcinoma, often with solid and nested growth patterns, as well as infiltrative glandular, tubulopapillary, cribriform, or reticular growth. Rhabdoid and sarcomatoid cytomorphology was seen in a subset. All tumors showed PAX8 nuclear positivity and SMARCB1 loss, with OCT3/4 expression in 4 of 5 cases. In summary, this first series of renal cell carcinoma, unclassified, with medullary phenotype documents tumors with morphologic, immunophenotypic, and prognostic features of RMC occurring in individuals without sickle cell trait. Although greater biologic and molecular understanding is needed, the available evidence points to these cases representing a sporadic counterpart to sickle cell trait-associated RMC.

Appendiceal goblet cell carcinoid: common errors in staging and clinical interpretation with a proposal for an improved terminology.

Goblet cell carcinoid (GCC) is staged and treated as adenocarcinoma (AC) and not as neuroendocrine tumor (NET) or neuroendocrine carcinoma. The term carcinoid may lead to incorrect interpretation as NET. The aim of the study was to explore pitfalls in staging and clinical interpretation of GCC and mixed GCC-AC, and propose strategies to avoid common errors. Diagnostic terminology, staging, and clinical interpretation were evaluated in 58 cases (27 GCCs, 31 mixed GCC-ACs). Opinions were collected from 23 pathologists using a survey. Clinical notes were reviewed to assess the interpretation of pathology diagnoses by oncologists. NET staging was incorrectly used for 25% of GCCs and 5% of mixed GCC-ACs. In the survey, 43% of pathologists incorrectly indicated that NET staging is applicable to GCCs, and 43% incorrectly responded that Ki-67 proliferation index is necessary for GCC grading. Two cases each of GCC and mixed GCC-AC were incorrectly interpreted as neuroendocrine neoplasms by oncologists, and platinum-based therapy was considered for 2 GCC-AC cases because of the mistaken impression of neuroendocrine carcinoma created by use of the World Health Organization 2010 term mixed adenoneuroendocrine carcinoma. The term carcinoid in GCC and use of mixed adenoneuroendocrine carcinoma for mixed GCC-AC lead to errors in staging and treatment. We propose that goblet cell carcinoid should be changed to goblet cell carcinoma, whereas GCC with AC should be referred to as mixed GCC-AC with a comment about the proportion of each component and the histologic subtype of AC. This terminology will facilitate appropriate staging and clinical management, and avoid errors in interpretation.

Perspectives on testicular sex cord-stromal tumors and those composed of both germ cells and sex cord-stromal derivatives with a comparison to corresponding ovarian neoplasms.

Sex cord-stromal tumors (SCSTs) are the second most frequent category of testicular neoplasms, accounting for approximately 2% to 5% of cases. Both genetic and epigenetic factors account for the differences in frequency and histologic composition between testicular and ovarian SCSTs. For example, large cell calcifying Sertoli cell tumor and intratubular large cell hyalinizing Sertoli cell neoplasia occur in the testis but have not been described in the ovary. In this article, we discuss recently described diagnostic entities as well as inconsistencies in nomenclature used in the recent World Health Organization classifications of SCSTs in the testis and ovary. We also thoroughly review the topic of neoplasms composed of both germ cells and sex cord derivatives with an emphasis on controversial aspects. These include "dissecting gonadoblastoma" and testicular mixed germ cell-sex cord stromal tumor (MGC-SCST). The former is a recently described variant of gonadoblastoma that sometimes is an immediate precursor of germinoma in the dysgenetic gonads of patients with a disorder of sex development. Although the relationship of dissecting gonadoblastoma to the previously described undifferentiated gonadal tissue is complex and not entirely resolved, we believe that it is preferable to continue to use the term undifferentiated gonadal tissue for those cases that are not neoplastic and are considered to be the precursor of classical gonadoblastoma. Although the existence of testicular MGC-SCST has been challenged, the most recent evidence supports its existence; however, testicular MGC-SCST differs significantly from ovarian examples due to both genetic and epigenetic factors.

Neuroendocrine, goblet cell and mixed adeno-neuroendocrine tumours of the appendix: updates, clinical applications and the future.

INTRODUCTION: Appendiceal neuroendocrine neoplasms are rare, clinically challenging tumours that are typically incidentally diagnosed, have a poorly understood biology and have controversy surrounding their management. Most are adequately treated with appendectomy, and although distant metastases are rare, the threat of disease dissemination remains and current guidelines possess poor accuracy in terms of selecting patients requiring more extensive surgery, i.e. oncological right-hemicolectomy. Areas covered: In this article, we discuss the presentation and diagnostic work-up of patients with appendiceal neuroendocrine neoplasms, and also examine the evidence base for existing management strategies. We highlight controversies within the management of these tumours, and anticipate avenues for further progress. Although no longer classified as neuroendocrine neoplasms, we also discuss two related forms of tumours with neuroendocrine features - goblet cell cancers and mixed adeno-neuroendocrine carcinomas. Expert commentary: Existing guidelines for the treatment of appendiceal neuroendocrine neoplasms are derived from a limited evidence base and are unable to accurately predict which patients require extensive attempts at surgical disease control. Future advances in the field of improved patient selection for more extensive surgery may be possible with multi-factorial tumour assessment integrating morphological and molecular analyses.

Tubulopapillary Cystic Adenoma With Apocrine Differentiation: A Unifying Concept for Syringocystadenoma Papilliferum, Apocrine Gland Cyst, and Tubular Papillary Adenoma.

Syringocystadenoma papilliferum (SCAP), apocrine gland cyst (AGC, also called apocrine hidrocystoma or apocrine cystadenoma), and tubular papillary adenoma (TPA) with apocrine differentiation are defined as proliferations of apocrine epithelium with myoepithelial cells. At Sapporo Dermatopathology Institute, we retrieved 308 benign neoplastic lesions diagnosed as SCAP, AGC, or TPA and combinations of these entities. Among the 308 lesions, 202 (66%) exhibited features of only one type, of which 144 (47%) were AGC, 39 (13%) were TPA, and 19 (6%) were SCAP. The other 106 lesions (34%) had features of 2 or more types, including 56 lesions that were AGC + TPA (18%), 2 that were AGC + SCAP (1%), 34 that were TPA + SCAP (11%), and 14 that were AGC + TPA + SCAP (5%). The most frequent site of these lesions was the face (56%), followed by the scalp (13%). Lesions with the features of AGC were more frequently found on the face, especially the periocular region, than at other sites. TPA lesions were more frequent on the face and scalp than at other sites, whereas SCAP lesions were preferentially found on the face, scalp, and trunk. We also retrieved clinicopathological data and other information. We propose a unifying concept for AGC, TPA, and SCAP. Approximately one-third of these lesions are composite entities with the features of 2 or 3 different tumors, and we propose calling such tumors tubulopapillary cystic adenoma with apocrine differentiation.

Mixed Neuroendocrine-Nonneuroendocrine Neoplasms (MiNENs): Unifying the Concept of a Heterogeneous Group of Neoplasms.

The wide application of immunohistochemistry to the study of tumors has led to the recognition that epithelial neoplasms composed of both a neuroendocrine and nonneuroendocrine component are not as rare as traditionally believed. It has been recommended that mixed neuroendocrine-nonneuroendocrine epithelial neoplasms are classified as only those in which either component represents at least 30 % of the lesion but this cutoff has not been universally accepted. Moreover, since their pathogenetic and clinical features are still unclear, mixed neuroendocrine-nonneuroendocrine epithelial neoplasms are not included as a separate clinicopathological entity in most WHO classifications, although they have been observed in virtually all organs. In the WHO classification of digestive tumors, mixed neuroendocrine-nonneuroendocrine neoplasm is considered a specific type and is defined as mixed adenoneuroendocrine carcinoma, a definition that has not been accepted for other organs. In fact, this term does not adequately convey the morphological and biological heterogeneity of digestive mixed neoplasms and has created some misunderstanding among both pathologists and clinicians. In the present study, we have reviewed the literature on mixed neuroendocrine-nonneuroendocrine epithelial neoplasms reported in the pituitary, thyroid, nasal cavity, larynx, lung, digestive system, urinary system, male and female genital organs, and skin to give the reader an overview of the most important clinicopathological features and morphological criteria for diagnosing each entity. We also propose to use the term "mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN)" to define and to unify the concept of this heterogeneous group of neoplasms, which show different characteristics mainly depending on the type of neuroendocrine and nonneuroendocrine components.

Clinicopathologic Characteristics of Hepatocellular Carcinoma With Reactive Ductule-like Components, a Subset of Liver Cancer Currently Classified as Combined Hepatocellular-Cholangiocarcinoma With Stem-Cell Features, Typical Subtype.

The aim of this study was to elucidate the clinicopathologic characteristics of hepatocellular carcinoma with reactive ductule-like components (HCC-RD), corresponding to combined hepatocellular-cholangiocarcinoma (CHC) with stem cell features, typical subtype. Retrospective clinicopathologic analysis was performed on HCCs surgically treated at the University of Tokyo Hospital between 1995 and 2013. RD components were defined as neoplastic ductular structures composed of small "stem/progenitor-like" cells. There were 46 HCC-RDs, comprising about 3% of all HCCs. Thirty-eight cases of CHC, classical type (classical CHC), were identified during the study period. When compared with conventional HCC, HCC-RD was characterized by younger patient age (P=0.016), higher frequency of female patients (P<0.001), and higher serum α-fetoprotein levels (P=0.005). Serum carbohydrate antigen 19-9 elevation was also more frequently observed in HCC-RD than in conventional HCC (P=0.002). Histologically, clear cell constituents and interstitial fibrosis were more frequent in HCC-RD than in conventional HCC (P=0.003 and <0.001, respectively). When compared with HCC-RD and conventional HCC, classical CHC was characterized by a poorly differentiated HCC component, frequent vascular invasion, and lymph node metastasis (P<0.05). There was little prognostic difference between HCC-RD and conventional HCC, whereas overall and disease-free survival in classical CHC was significantly worse than in conventional HCC. In conclusion, although HCC-RDs do have some unique clinicopathologic characteristics, they have no prognostic significance, and it is not reasonable to include these tumors in the CHC category.

Nonchoriocarcinomatous Trophoblastic Tumors of the Testis: The Widening Spectrum of Trophoblastic Neoplasia.

Tumors of trophoblastic derivation other than choriocarcinoma are very rare in the testis but have been reported on occasion in association with other germ cell tumors. Their morphologic spectrum is analogous to the trophoblastic tumors of the female genital tract including epithelioid trophoblastic tumor (ETT) and placental site trophoblastic tumor (PSTT). Herein we report our experience with 8 cases of trophoblastic tumors of testicular origin that lacked the features of choriocarcinoma; these included 4 ETTs, 1 PSTT, 1 unclassified trophoblastic tumor (UTT), 1 partially regressed choriocarcinoma with a monophasic morphology, and 1 hybrid tumor showing a mixture of adenocarcinoma and a UTT. All tumors occurred in young men 19 to 43 years old. Five arose de novo within the testis (2 ETTs, 1 UTT, 1 regressing choriocarcinoma, and the hybrid tumor) as a component of mixed germ cell tumors, and 3 (2 ETTs and 1 PSTT) were found in metastatic sites after chemotherapy. The trophoblastic component was minor (5% to 10%) in 6 tumors but was 95% of 1 metastatic tumor (ETT) and 50% of the hybrid tumor. Other germ cell tumor elements were identified in all cases, most commonly teratoma. The ETTs consisted of nodules and nests of squamoid trophoblast cells showing abundant eosinophilic cytoplasm, frequent apoptotic cells, extracellular fibrinoid material, and positivity for p63 and negativity for human placental lactogen (HPL). The PSTT showed sheets of discohesive, pleomorphic, mononucleated trophoblast cells that invaded blood vessels with fibrinoid change and were p63 negative and HPL positive. The UTT showed a spectrum of small and large trophoblast cells, some multinucleated but lacking distinct syncytiotrophoblasts, and was patchily positive for both p63 and HPL. The hybrid tumor had ETT-like and adenocarcinomatous areas that coexpressed inhibin and GATA3 but were negative for p63 and HPL, leading to classification of the trophoblastic component as UTT. Seven of the patients were alive and well on follow-up (8 to 96 mo; median, 39 mo), whereas the patient with the hybrid tumor died of liver metastases at 2 years. Our study verifies that trophoblastic neoplasms often having the features of nonchoriocarcinomatous gestational trophoblastic tumors may arise from the testis, occur either in the untreated primary tumor or in metastases after chemotherapy, and should be distinguished from choriocarcinoma given what appears to be a less aggressive clinical course.

Benign cutaneous biphasic hybrid tumor of perineurioma and cellular neurothekeoma: A case report expanding the clinical and histopathologic features of a recently described entity.

Benign cutaneous plexiform hybrid tumor of perineurioma and cellular neurothekeoma (BCPHTPCN) is a recently described entity that presents as a solitary papule in the perioral area. As implied by its name, BCPHTPCN displays microscopic features of both perineurioma and cellular neurothekeoma arranged in a plexiform pattern. We report a case of nonplexiform benign cutaneous biphasic hybrid tumor of perineurioma and cellular neurothekeoma in a 36-year-old woman, who presented with a 4-year history of a firm, flesh-colored left ankle nodule. Histologically, there was a biphasic, well-circumscribed unencapsulated dermal mesenchymal proliferation with no connection to the epidermis, which exhibited mild acanthosis with slightly pigmented basal keratinocytes and overlying parakeratosis. The proliferation consisted of uniform bland spindle cells with bipolar cytoplasmic processes arranged in whorls with interspersed islands of epithelioid cells. Immunohistochemically, the spindle cell component was positive for CD34, EMA, and GLUT-1, consistent with perineurial differentiation, whereas the epithelioid nests were positive for NKI/C3 and MiTF, as expected in neurothekeoma. Stains for S100 protein, SOX10, desmin, claudin, pan-melanoma markers, and NSE were negative. We believe this case expands the histopathologic spectrum of BCPHTPCN showing that it can be grown in a nonplexiform pattern, and we suggest the term benign cutaneous biphasic hybrid tumor of perineurioma and cellular neurothekeoma as a more precise name. It is also, to the best of our knowledge, the first case reported outside the head and neck area.

Histopathology of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is currently the sixth most common type of cancer with a high mortality rate and an increasing incidence worldwide. Its etiology is usually linked to environmental, dietary or life-style factors. HCC most commonly arises in a cirrhotic liver but interestingly an increasing proportion of HCCs develop in the non-fibrotic or minimal fibrotic liver and a shift in the underlying etiology can be observed. Although this process is yet to be completely understood, this changing scenario also has impact on the material seen by pathologists, presenting them with new diagnostic dilemmas. Histopathologic criteria for diagnosing classical, progressed HCC are well established and known, but with an increase in detection of small and early HCCs due to routine screening programs, the diagnosis of these small lesions in core needle biopsies poses a difficult challenge. These lesions can be far more difficult to distinguish from one another than progressed HCC, which is usually a clear cut hematoxylin and eosin diagnosis. Furthermore lesions thought to derive from progenitor cells have recently been reclassified in the WHO. This review summarizes recent developments and tries to put new HCC biomarkers in context with the WHOs reclassification. Furthermore it also addresses the group of tumors known as combined hepatocellular-cholangiocellular carcinomas.

Proposed morphologic classification of prostate cancer with neuroendocrine differentiation.

On July 31, 2013, the Prostate Cancer Foundation assembled a working committee on the molecular biology and pathologic classification of neuroendocrine (NE) differentiation in prostate cancer. New clinical and molecular data emerging from prostate cancers treated by contemporary androgen deprivation therapies, as well as primary lesions, have highlighted the need for refinement of diagnostic terminology to encompass the full spectrum of NE differentiation. The classification system consists of: Usual prostate adenocarcinoma with NE differentiation; 2) Adenocarcinoma with Paneth cell NE differentiation; 3) Carcinoid tumor; 4) Small cell carcinoma; 5) Large cell NE carcinoma; and 5) Mixed NE carcinoma - acinar adenocarcinoma. The article also highlights "prostate carcinoma with overlapping features of small cell carcinoma and acinar adenocarcinoma" and "castrate-resistant prostate cancer with small cell cancer-like clinical presentation". It is envisioned that specific criteria associated with the refined diagnostic terminology will lead to clinically relevant pathologic diagnoses that will stimulate further clinical and molecular investigation and identification of appropriate targeted therapies.

Composite hemangioendothelioma and its classification as a low-grade malignancy.

Hemangioendotheliomas are vascular neoplasms occupying a spectrum of biological potential ranging from benign to low-grade malignancy. Composite hemangioendothelioma (CH) is one of the less commonly encountered variants exhibiting a mixture of elements of other hemangioendothelioma subtypes, such as epithelioid, retiform, and spindle cell. Some authors have identified areas histopathologically equivalent to angiosarcoma within CH, raising the question of the true nature of this neoplasm. Although CH recurs locally, there are only 3 reported cases which metastasized. To date, 26 cases (including the present case) have been described in the literature. Herein, we describe a unique case of CH arising in the background of previous radiation therapy and long-standing lymphedema (classically associated with the development of angiosarcoma-Stewart-Treves syndrome) that harbored higher grade areas but behaved as a low-grade malignant neoplasm. This, in conjunction with the many reported cases of CH-harboring angiosarcoma-like areas, and the occasional association with a history of lymphedema, raises the question of whether this variant of hemangioendothelioma may actually be an angiosarcoma that behaves prognostically better than the conventional type. After careful study of the natural disease progression of the current case and review of the literature, we discuss justification for the continued classification of CH as a low-grade malignancy.

Cytologic features of focal papillary thyroid carcinoma arising within follicular adenoma: a masked cytomorphologic analysis of 17 cases.

BACKGROUND/OBJECTIVE: Focal papillary thyroid carcinoma (PTC) arising within a follicular adenoma (PTCFA) represents a clinically significant, but rare, histopathologic subset of papillary carcinomas whose cytologic features have not been well described. This uncommon presentation of PTC may contribute to a subset of thyroid aspirates interpreted as 'atypia of undetermined significance/follicular lesion of undetermined significance' (AUS/FLUS). STUDY DESIGN: Seventeen fine-needle aspiration biopsy (FNAB) cases diagnosed as 'PTCFA' on corresponding surgical excision were identified from the archival records of 2 large academic medical centers. A control group of 40 FNAB comprised of 20 follicular adenomas (FA) and 20 PTC was identified (based on the corresponding surgical pathology diagnosis) for comparison. All 57 FNAB were reviewed in a masked fashion and scored for a series of 31 cytomorphologic features. The intraclass correlation between diagnostic categories and overall agreement between cytopathologists was statistically evaluated. RESULTS: Aspirates of PTCFA were originally diagnosed as 'negative' (n = 3), 'AUS/FLUS' (n = 7), 'suspicious for a follicular neoplasm' (n = 3), 'suspicious for malignancy' (n = 3), and 'malignant' (n = 1). On masked review, the most common cytomorphologic features of PTCFA were a nonmacrofollicular cytoarchitectural pattern (71%), medium-large cell size (74%), and micronucleoli (79%). Intranuclear pseudoinclusions and a papillary architecture were absent in 85 and 88% of the cases, respectively. Relative to the 2 control groups, the PTCFA cases demonstrated overlapping features between FA and PTC for the majority of the 31 examined cytomorphologic features. CONCLUSION: PTCFA represent a rare subset of PTC that is difficult to recognize as PTC by FNAB. Most cases exhibit overlapping features between a benign thyroid nodule and conventional PTC, and they are often interpreted as 'AUS/FLUS'.

Colorectal glandular-neuroendocrine mixed tumor: pathologic spectrum and clinical implications.

Colorectal glandular-neuroendocrine mixed tumor is an uncommon entity with ill-defined clinicopathologic characteristics. We describe the clinicopathology of 23 new cases and review 67 previously reported cases. Clinically, patients (mean age, 61.9 y; male: female, 1.0:1.1) presented with a positive fecal occult blood test or visible rectal bleeding (44%), abdominal pain or change in bowel movement pattern (25%), bowel obstruction (19%), or weight loss (19%). Endoscopically, the tumors presented as a polypoid lesion (57%), a mass lesion (30%), or an ulcerating lesion (9%). Tumors were located in the right colon (56%), transverse colon (3%), and left colon (41%). Surgical resection was the treatment of choice in 83% of cases. After follow-up for an average of 20 months, the tumor-related death rate was 68%. Histologically, 42% were classified as composite tumors and 58% were classified as collision tumors. An adenoma to carcinoma, and then carcinoma to mixed tumor progression through the APC/ß-catenin pathway was seen in a majority of cases. Both the glandular and the neuroendocrine components of the mixed tumor can show a spectrum of differentiation, and each component can metastasize separately regardless of its percentage volume. On the basis of the combined analysis of the pathologic spectrum and the clinical behavior of our series and previously reported cases, we propose a new classification system that reflects the differentiation of each component in colorectal glandular-neuroendocrine mixed tumor to facilitate uniform reporting and to better predict its clinical behavior.

[Histological classification of human gliomas: state of art and controversies]. / Classification anatomopathologique des gliomes: faits et controverses.

The histological classification of human gliomas remains in 2005 a challenge. The aim is to define the histological type of glioma (astrocytic, oligodendrocytic or mixed) and the grade in order to classify the patients and give them an accurate treatment. Although the standard remains the WHO classification, this classification suffered from lack of reproducibility among pathologists. In particular this classification does not take into account the intrinsic morphological heterogeneity of infiltrative gliomas and does not discriminate the tumour cells from the residual brain parenchyma. According to the WHO classification, infiltrative gliomas encompass astrocytic gliomas (diffuse astrocytomas grade II, anaplastic astrocytomas grade III and glioblastomas grade IV), oligodendroglial tumours (oligodendrogliomas grade II, anaplastic oligodendrogliomas grade III) and mixed gliomas (oligoastrocytomas grade II and anaplastic oligoastrocytomas grade III). Circumscribed gliomas mainly corresponds to pilocytic astrocytomas (grade I). In contrast, the Sainte Anne classification takes into account the macroscopic informations provided by imaging techniques and the tumour growth patterns. Three distinct tumour growth patterns may be seen in gliomas, type I: tumor tissue only, type II: tumour tissue and isolated tumor cells permeating the brain parenchyma (ITC) and type III: ITCs only and no tumor tissue. According to the Sainte Anne classification, gliomas are divided into astrocytic gliomas (pilocytic astrocytomas, structure type I, glioblastomas structure type II) and oligodendrogliomas and mixed oligoastrocytomas (grade A: lack of contrast enhancement and lack of endothelial hyperplasia, structure type III; and grade B: contrast enhancement or endothelial hyperplasia, structure type II and III). In the future the glioma classification has to be unique and should take into account clinical data, neuroradiological and histological features and results of molecular biology.