Cytokeratin-immunoreactive cells of human lymph nodes and spleen in normal and pathological conditions. An immunocytochemical study

Cytokeratin-positive interstitial reticulum cell (CIRC) tumor in the lymph node: a case report of the transformation from the epithelioid cell type to the spindle cell type

Background

Cytokeratin-positive interstitial reticulum cells (CIRCs), which are a subgroup of fibroblastic reticular cells (FRCs), are known to be present in the lymph nodes. There have been only a few cases of tumors derived from CIRCs.

Case presentation

We have reported a new case involving a CIRC tumor in a 75-year-old man and reviewed the literature. The resected mediastinal lymph nodes showed epithelial-like proliferation of large atypical round and polygonal epithelioid cells. The tumor cells expressed CK8, CK18, CAM5.2, AE1/AE3, epithelial membrane antigen, vimentin, fascin, and some FRC markers, which is consistent with the diagnosis of a CIRC tumor. Following chemotherapy, the CIRC tumor was observed to have responded very well and became difficult to confirm on imaging, but a small cell lung carcinoma developed 12 months later. Chemoradiotherapy was performed, but the patient passed away 29 months after the initial diagnosis. The autopsy revealed the recurrence of the CIRC tumor, residual small cell lung carcinoma, and a very small latent carcinoma of the prostate. The relapsed CIRC tumor cells had a spindle shape; they were highly pleomorphic and had invaded the superior vena cava.

Conclusion

We first reported autopsy findings of CIRC tumors and demonstrated the transformation of the tumor from the epithelioid cell type to the spindle cell type.

Detection of disseminated tumor cells in lymph nodes from patients with early stage non-small cell lung cancer

BACKGROUND

The regional lymph node involvement is a major prognostic factor in patients with non-small cell lung cancer (NSCLC) undergoing surgical resection. Disease relapse is common, suggesting that early disseminated disease is already present in the regional lymph nodes at the time of surgery, and that the current nodal staging classification might be suboptimal. Early detection of disseminated tumor cells (DTCs) in lymph nodes could potentially enable identification of subcategories of patients with high risk of disease relapse.

METHOD

Lymph node samples were collected from 128 NSCLC patients at the time of surgery and the presence of DTCs determined by immunomagnetic selection (IMS) using the MOC31 antibody recognizing EpCAM. Results obtained with IMS were compared to the pathological staging obtained by histopathology. Associations between the presence of DTCs and clinicopathological variables and patient outcome were investigated.

RESULTS

DTCs were detected in 40 % of the lymph node samples by IMS. Their presence was significantly associated with pN status as assessed by histopathology, and samples from 83 % of the patients with lymph node metastases (pN1-2) had detectable DTCs. In the group of patients who were negative for lymph node metastases by standard histopathology (pN0) DTCs were detected in 32 %. The presence of DTCs was not associated with any other clinicopathological variables. Patients with IMS-positive samples showed decreased relapse free survival compared to patients with IMS-negative samples, but the difference was not statistically significant. The pN status was significantly associated with both relapse free and overall survival, but the presence of DTCs had no prognostic impact in the subcategory of patients with pN0 status.

CONCLUSION

Our findings do not support further development of lymph node DTC detection for clinical use in early stage NSCLC.

Cytokeratin-positive interstitial reticulum cell tumor: recognition of a potential "in situ" pattern

Cytokeratin-positive interstitial reticulum cell (CIRC) tumor is a very rare accessory cell neoplasm of lymphoid organs derived from fibroblastic reticulum cells, which originate from mesenchymal stem cells. We describe the histologic, immunophenotypical, and molecular features of a CIRC tumor in a 67-year-old woman who underwent hysterectomy, bilateral adnexectomy, and pelvic lymphadenectomy for endometrial carcinoma. An enlarged pelvic node contained circumscribed neoplastic infiltrates in perifollicular and interfollicular areas consisting of large cells arranged in a reticular pattern with nuclear atypia, atypical mitoses, and apoptosis, but without glandular architecture or disruption of overall architecture. The atypical infiltrate coexpressed cytokeratin and vimentin, partially CD68, CD163, and lysozyme, but lacked markers of endometrial carcinoma, consistent with a diagnosis of CIRC tumor. Despite the obviously neoplastic cytological features, immunostains revealed the circumscribed and noninvasive pattern of the lesion, possibly representing an early "in situ" stage of CIRC tumor.

Cytokeratin-positive fibroblastic reticular cell tumor with follicular dendritic cell features: a case report and review of the literature

Fibroblastic reticular cell (FRC) neoplasms, which are one of the histiocyte tumor types, are very rare. Here we report a cytokeratin (CK)-positive FRC neoplasm having features of follicular dendritic cells in a 54-year-old woman with right axillary lymph node swelling. The resected lymph node showed multiple nodular aggregations simulating and replacing normal follicles. The tumor cells had a uniform, large and oval to polygonal shape, abundant cytoplasm, and various sizes of nuclei with central eosinophilic nucleoli and coarse nuclear chromatin. They were positive for CK AE1/AE3+CAM5.2, CK7, tenascin C, l-caldesomone, and CD21, weakly positive for S100, and negative for CD1a. Ultrastructurally, the tumor cells had long interdigitating microvillus-like cell processes and oval to elongated vesicular nuclei. In addition, the intercellular spaces contained accumulations of collagen, and some tumor cells had desmosomal-like junctions. These findings suggest that the present case is a CK-positive FRC tumor with follicular dendritic cell features.

Heterogeneity of stromal cells in the human splenic white pulp. Fibroblastic reticulum cells, follicular dendritic cells and a third superficial stromal cell type

At least three phenotypically and morphologically distinguishable types of branched stromal cells are revealed in the human splenic white pulp by subtractive immunohistological double-staining. CD271 is expressed in fibroblastic reticulum cells of T-cell zones and in follicular dendritic cells of follicles. In addition, there is a third CD2711- and CD271+/) stromal cell population surrounding T-cell zones and follicles. At the surface of follicles the third population consists of individually variable partially overlapping shells of stromal cells exhibiting CD90 (Thy-1), MAdCAM-1, CD105 (endoglin), CD141 (thrombomodulin) and smooth muscle α-actin (SMA) with expression of CD90 characterizing the broadest shell and SMA the smallest. In addition, CXCL12, CXCL13 and CCL21 are also present in third-population stromal cells and/or along fibres. Not only CD27+ and switched B lymphocytes, but also scattered IgD++ B lymphocytes and variable numbers of CD4+ T lymphocytes often occur close to the third stromal cell population or one of its subpopulations at the surface of the follicles. In contrast to human lymph nodes, neither podoplanin nor RANKL (CD254) were detected in adult human splenic white pulp stromal cells. The superficial stromal cells of the human splenic white pulp belong to a widespread cell type, which is also found at the surface of red pulp arterioles surrounded by a mixed T-cell/B-cell population. Superficial white pulp stromal cells differ from fibroblastic reticulum cells and follicular dendritic cells not only in humans, but apparently also in mice and perhaps in rats. However, the phenotype of white pulp stromal cells is species-specific and more heterogeneous than described so far.

Fibroblastic Reticulum Cell Tumor of Spleen: A Case Report

Fibroblastic reticulum cells (FBRCs) belong to a major subtype of stromal support cells in the lymphoid system and rarely give rise to tumors. We report a case of fibroblastic reticulum cell tumor arising in the spleen. The tumor was clinically and radiologically mistaken for a metastatic deposit in the spleen. Microscopically the tumor was composed of spindle cells arranged in fascicles and storiform pattern. The cells had oval to elongated vesicular nuclei and pale eosinophilic cytoplasm with indistinct cell borders. There were admixed inflammatory cells, including large numbers of plasma cells. The tumor cells were positive for smooth muscle actin, desmin, AE1/AE3, and MNF116. They were negative for S100, CD1a, CD21, CD23, CD34, CD31, and CD35 among other markers. The morphological features and immunoprofile of this rare tumor in comparison to the few cases reported in the literature are discussed along with the positive reaction with cytokeratins and their relationship to the smaller subset of FBRCs, the cytokeratin-positive interstitial reticulum cells in the spleen.

Endothelial and virgultar cell formations in the mammalian lymph node sinus: endothelial differentiation morphotypes characterized by a special kind of junction (complexus adhaerens)

The lymph node sinus are channel structures of unquestionable importance in immunology and pathology, specifically in the filtering of the lymph, the transport and processing of antigens, the adhesion and migration of immune cells, and the spread of metastatic cancer cells. Our knowledge of the cell and molecular biology of the sinus-forming cells is still limited, and the origin and biological nature of these cells have long been a matter of debate. Here, we review the relevant literature and present our own experimental results, in particular concerning molecular markers of intercellular junctions and cell differentiation. We show that both the monolayer cells lining the sinus walls and the intraluminal virgultar cell meshwork are indeed different morphotypes of the same basic endothelial cell character, as demonstrated by the presence of a distinct spectrum of general and lymphatic endothelial markers, and we therefore refer to these cells as sinus endothelial/virgultar cells (SEVCs). These cells are connected by unique adhering junctions, termed complexus adhaerentes, characterized by the transmembrane glycoprotein VE-cadherin, combined with the desmosomal plaque protein desmoplakin, several adherens junction plaque proteins including alpha- and beta-catenin and p120 catenin, and components of the tight junction ensemble, specifically claudin-5 and JAM-A, and the plaque protein ZO-1. We show that complexus adhaerentes are involved in the tight three-dimensional integration of the virgultar network of SEVC processes along extracellular guidance structures composed of paracrystalline collagen bundle "stays". Overall, the SEVC system might be considered as a local and specific modification of the general lymphatic vasculature system. Finally, physiological and pathological alterations of the SEVC system will be presented, and the possible value of the molecular markers described in histological diagnoses of autochthonous lymph node tumors will be discussed.

The clinical significance of lymph node micrometastasis in stage I and stage II colorectal cancer

AIM

Recent advances in immunohistochemical techniques have made it possible to identify micrometastasis using antibodies to cytokeratins (CK). The aim of the study was to determine the prevalence and prognostic significance of immunohistochemically detected micrometastasis (IHM) in patients with localised colorectal cancer (CRC) (Dukes' A and B). A further aim was to study the prognostic role of histopathological factors such as vascular invasion.

METHODS

The original histology of 168 consecutive patients with Dukes' A or B tumours who had undergone curative resection was reviewed. Immunohistochemical staining was performed using CK antibodies, AE1/AE3 and MNF116 on all (n=898) lymph nodes. Survival analysis was performed on 105 cases that had been followed up until death or for at least 5 years.

RESULTS

IHM were detected in 17.3% of lymph nodes analysed. Adverse outcome (death/local recurrence) was recorded in 8/49 (16%) patients with IHD-positive nodes and in 10/56 (18%) patients negative for IHM. IHM was not associated with adverse outcome on either univariate (p=0.540) or multivariate analyses (p=0.673). There was no correlation of IHM with age, gender, site, size and grade of tumour, depth of tumour invasion or perineural and vascular invasion. Vascular invasion was the only independent prognostic factor identified.

DISCUSSION

We have shown that isolated CK-positive epithelioid cells are commonly found in morphologically benign pericolic lymph nodes of patients with localised (Dukes' A or B) CRC. These cells may represent occult micrometastasis but are not clinically significant. Vascular invasion identifies patients with localised CRC likely to develop recurrences or die of disease.

Application of immunohistochemistry to breast lesions

CONTEXT

Immunohistochemistry has an expanding role in mammary pathology that has been facilitated by a growing list of available antibodies and a better understanding of biology.

OBJECTIVE

To explore the key role of immunohistochemistry in guiding adjuvant therapy decisions and sentinel node staging in breast cancer, as well as the role of immunohistochemistry as an aid to distinguishing usual ductal hyperplasia from atypical ductal hyperplasia/low-grade carcinoma in situ; subtyping a carcinoma as ductal or lobular, basal or luminal; ruling out microinvasion in extensive intraductal carcinoma; distinguishing invasive carcinoma from mimics; and establishing that a metastatic carcinoma of unknown primary site has originated in the breast.

DATA SOURCES

Current literature is reviewed, including clinical and pathologic journals.

CONCLUSIONS

As new, targeted treatments for breast cancer are developed, pathologists can expect additional immunohistochemistry applications in the future.

Combination analysis of a whole lymph node by one-step nucleic acid amplification and histology for intraoperative detection of micrometastasis

OBJECTIVE

The aim was to develop a more efficient molecular detection system than histological examination (HE) for lymph node (LN) metastasis.

METHODS

Cytokeratin (CK) 19 mRNA copy numbers of 5 colon carcinoma cell lines (Lovo, DLD1, WiDr, Colo201 and Colo320) were calculated and compared by one-step nucleic acid amplification (OSNA) and conventional real-time reverse-transcription polymerase chain reaction (RT-PCR). Then, 91 LN submitted for HE from 6 patients with advanced colorectal adenocarcinoma and 64 LN submitted for frozen diagnosis from 47 patients with different malignancies were examined by OSNA and HE.

RESULTS

CK19 mRNA copy numbers of all but Colo320 cells detected by OSNA were within double of those detected by RT-PCR. The least cell count of Lovo cells detected at one reaction (2 microl) by OSNA was calculated as 0.8 cells. Carcinoma metastasis showing either HE+ or OSNA+ was detected in 7.9% of the LN from advanced colorectal adenocarcinomas and in 30.0% of the LN for frozen diagnosis from different malignancies; HE-/OSNA+ metastasis was detected in 4.8 and 4.0%, respectively. OSNA analysis of 1 LN could be completed within 40 min.

CONCLUSION

A combined analysis of LN by HE and OSNA could increase the sensitivity for detecting micrometastasis during surgery.

Pathologic examination of the axillary sentinel lymph nodes in patients with early-stage breast carcinoma: current and resolving controversies on the basis of the European Institute of Oncology experience

Several controversial aspects of sentinel lymph node biopsy (SLNB) for patients with early-stage, node-negative breast carcinoma have been dealt with and resolved in the past decade since its introduction. Unfortunately, however, there is still no consensus on how best to examine sentinel lymph nodes (SLN) histologically. As a consequence, the protocols for SLN examination are remarkably variable in different institutions, leading to a very poor reproducibility of the data stemming from investigations on series of patients whose SLNs have been evaluated according to diverse protocols. Patient outcomes, however, can be optimised only by standardization of the whole procedure of SLNB, with particular reference to the histopathologic scrutiny. Lack of a standardized histopathologic protocol likely derives also from the uncertainties about the clinical implications of minimal lymph node involvement (isolated tumour cells and micrometastases) with regard both to the risk of additional metastases to non-sentinel lymph nodes of the same basin and to the prognostic value for patients' survival. This review aims at highlighting some of the controversial issues of the histopathologic examination of the SLNs, including the number of sections and cutting intervals, the use of immunohistochemistry and the role of molecular biology assays.

Detection of Micrometastatic Disease in Bone Marrow: Is It Ready for Prime Time?

Minimal residual disease (MRD), or isolated tumor cells (ITCs) in bone marrow, may be the source of potentially fatal overt distant metastases in solid tumors even years after primary treatment. MRD can be detected by immunohistochemical methods using antibodies directed against cytokeratins or cell-surface markers or molecular, polymerase chain reaction-based techniques. Among solid tumors, the clinical relevance of MRD has been most extensively studied in breast cancer patients. Recently, the highest level of evidence for the prognostic impact of MRD in primary breast cancer was reached by a pooled analysis comprising more than 4,000 patients, showing poor outcome in patients with MRD at primary therapy. Yet the clinical application of MRD detection is hampered by the lack of a standardized detection assay. Moreover, clinical trial results demonstrating the benefit of a therapeutic intervention determined by bone marrow status are still absent. Recent results suggest that, in addition to its prognostic impact, MRD can be used for therapy monitoring or as a potential therapeutic target after phenotyping of the tumor cells. Persistent MRD after primary treatment may lead to an indication for extended adjuvant therapy. However, until clinically relevant data regarding successful therapy of MRD are available, treatment interventions on the basis of MRD should only be performed within clinical trials.

So-called inflammatory myofibroblastic tumour: a proliferative lesion of fibroblastic reticulum cells?

The term inflammatory pseudotumour was originally used in a generic fashion for any lesion which simulated a neoplastic condition at a clinical, macroscopic and microscopic level but which was thought to have an inflammatory/reactive pathogenesis. In more recent times, the term has been employed in a more restrictive sense for a mass lesion characterized microscopically by the proliferation of a spindle cell component against a heavy inflammatory infiltrate of mixed composition but usually with a predominance of mature lymphocyte and plasma cells. The spindle cell component has generally been regarded as being of mesenchymal nature and having morphological and phenotypical features consistent with fibroblasts or myofibroblasts, the latter cell being clearly preferred over the former in the more resent reports. The term inflammatory myofibroblastic tumour (IMFT) is the one currently favoured, which proposes the myofibroblastic nature of the process. It is the purpose of this review to bring forth some evidence that the neoplastic spindle cell component of IMFT may be instead derived from the subtype of cells of the accessory immune system that have been variously called fibroblastic reticulum cells, myoid cells, and dictyocytes.

The clinical significance of axillary lymph node micrometastases in breast cancer

OBJECTIVE

To evaluate the clinical significancer of axillary lymph-node micrometastases, in the era of sentinel lymph node (SLN) biopsy.

DATA SOURCES

Searches of MEDLINE (1966-2003) and an extensive manual review of journals were performed using the key search terms breast cancer, axillary lymph-node micrometastases, micrometastatic disease, and SLN biopsy.

STUDY SELECTION

All articles identified from the data sources were evaluated and all information deemed relevant was included for this review.

CONCLUSIONS

Axillary lymph-node micrometastases can be detected by serial sectioning, immunohistochemistry, or reverse transcriptase-polymerase chain reaction (RT-PCR). The presence of axillary SLN micrometastases is generally associated with a worse prognosis and is an indication for axillary lymph node dissection (ALND) and adjuvant therapy. The clinical significance of micrometastases identified by RT-PCR remains unknown and further research with longer follow-up is needed to ascertain the clinical implications of a positive result.

Histopathologic examination of axillary sentinel lymph nodes in breast carcinoma patients

The axillary sentinel lymph node biopsy (SLNB) has gained increasing popularity as a novel surgical approach for staging patients with breast carcinoma and for guiding the choice of adjuvant therapy with minimal morbidity. Patients with negative SLNB represent a subset of breast carcinoma patients with definitely better prognosis, because their pN0 status is based on a very thorough examination of the sentinel lymph nodes (SLNs), with a very low risk of missing even small micrometastatic deposits, as compared with routine examination of the 20 or 30 lymph nodes obtained by the traditional axillary clearing. The histopathologic examination of the SLNs may be performed after fixation and embedding in paraffin, or intraoperatively on frozen sections. Whatever is the preferred tracing technique and surgical procedure, the histopathologic examination of each SLN must be particularly accurate, to avoid a false-negative diagnosis. Unfortunately, because of the lack of standardised guidelines or protocols for SLN examination, different institutions still adopt their own working protocols, which differ substantially in the number of sections cut and examined, in the cutting intervals (ranging from 50 to more than 250 microm), and in the more or less extensive use of immunohistochemical assays for the detection of micrometastatic disease. Herein, a very stringent protocol for the examination of the axillary SLN is reported, which is applied either to frozen SLN for the intraoperative diagnosis, and to fixed and embedded SLN as well.

Lymph node reticulum cell neoplasm with progression into cytokeratin-positive interstitial reticulum cell (CIRC) sarcoma: a case study

AIMS

To detail on sequential biopsies the morphological and immunohistochemical features of a case of primary lymph nodal fibroblastic reticulum cell (FBRC) tumour which progressed into a clinically aggressive cytokeratin-positive interstitial reticulum cell (CIRC) sarcoma.

METHODS AND RESULTS

A 70-year-old female underwent surgical excision of an enlarged submandibular lymph node. The nodal architecture was effaced by a neoplastic proliferation of medium to large cells, round to oval to spindle in shape, growing in a storiform pattern. The tumour stained for vimentin, CD68, factor XIIIa, alpha1-antitrypsin, fascin and actin. Dendritic and endothelial cell markers were negative. A diagnosis of FBRC tumour was made by combining pathological and clinical data. The patient received no therapy but 5 months later the tumour relapsed, exhibiting a deceptively pleomorphic cytology, phenotypic changes (strong cytokeratin positivity), intense p53 expression and aggressive clinical course with fatal outcome. In-situ hybridization for Epstein-Barr virus was negative.

CONCLUSIONS

We speculate that the morphological changes and p53 expression of the relapsing neoplasm might reflect tumour cell dedifferentiation, in keeping with the aggressive clinical course. The intense p53 expression suggests that this oncoprotein might also play a role in reticulum cell tumorigenesis.

Fibroblastic reticular cell tumor of the spleen: report of a case and review of the entity

Fibroblastic reticulum cells (FBRCs) are stromal support cells located in the parafollicular area and deep cortex of lymph nodes and in the extrafollicular areas of the spleen and tonsils. We report a case of malignant FBRC tumor of the spleen occurring in a 61-year-old woman. Two years after splenectomy, multiple hepatic lesions were found, which were resected. Histologically, the tumor showed similar morphological features in the spleen as in the liver metastases. There was a whorled pattern of oval and spindle cells in a collagenized background admixed with an inflammatory cell infiltrate composed of lymphocytes and plasma cells. The tumor cells were positive for common muscle actin, smooth muscle actin, and focally for CD68. In situ hybridization for Epstein Barr virus was negative. To the best of our knowledge, this is the first report of malignant FBRC tumor arising in the spleen. The differential diagnosis of splenic tumors with inflammatory pseudotumor-like features is discussed.

Cytokeratin-positive interstitial cell neoplasm: a case report and classification issues

AIMS

Tumours of dendritic/accessory cell origin are rare neoplasms arising in lymph nodes. Among these, tumours derived from cytokeratin-positive interstitial reticulum cells (CIRCs), a subset of fibroblastic reticulum cells, are reported even less frequently. The International Lymphoma Study Group (ILSG) has recently proposed a classification for tumours of histiocytes and accessory dendritic cells in which CIRC tumours are not included. We report a case of a CIRC tumour arising in a submandibular lymph node of a 66-year-old male.

METHODS AND RESULTS

The neoplasm was composed of spindle cells with elongated or round nuclei, prominent nucleoli and abundant cytoplasm. These cells were arranged in a diffuse fascicular and vaguely whorled pattern. The tumour cells stained diffusely for S100, vimentin, desmin, lysozyme, and focally for CD68 and cytokeratins 7, 8, 18, CK-AE1 and CK-pool. Electron microscopy was performed for further evaluation on samples taken from the paraffin block; this revealed cytoplasmic projections and rudimentary cell junctions.

CONCLUSIONS

Histopathologist should be aware of the existence of tumours deriving from CIRCs, as these cases may be misdiagnosed as metastatic carcinoma. Careful clinical and pathological evaluation is necessary to exclude this possibility.

Ectopic breast tissue as a possible cause of false-positive axillary sentinel lymph node biopsies

Epithelial inclusions representing ectopic breast tissue are uncommonly seen in axillary lymph nodes. The extensive histopathologic examination of axillary sentinel lymph nodes of patients with breast carcinoma may increase the chances to encounter tiny foci of ectopic breast tissue, which may be misinterpreted as (micro)metastatic disease and lead to unwarranted completion of axillary dissection and to inaccurate staging and improper adjuvant treatments for the patients. Here we report on seven cases of ectopic breast tissue in axillary sentinel lymph nodes. In three cases there were coexistent micrometastases, and in the remaining cases the ectopic tissue was not associated with metastatic disease. The ectopic breast tissue showed remarkably varied morphologic features, including apocrine metaplasia and proliferative changes indistinguishable from those occurring in sclerosing adenosis and florid epithelial hyperplasia of the breast. A peripheral layer of myoepithelial cells was consistently detected in the ectopic glands and ducts. Besides awareness and purely morphologic criteria, a false-positive identification of these inclusions as metastatic carcinoma may be avoided by the use of immunohistochemical reactions for the localization of specific markers of the myoepithelial cell component, which is associated with the ectopic breast tissue.

Patterns of disease recurrence influenced by hematogenous tumor cell dissemination in patients with cervical carcinoma of the uterus

BACKGROUND

The presence of isolated tumor cells (ITC) in the bone marrow at the time of primary diagnosis indicates an increased risk for subsequent development of distant metastases in various solid tumors. This study evaluates the prevalence and prognostic significance of ITC in patients with primary carcinoma of the cervix uteri.

METHOD

We immunocytochemically analyzed bone marrow aspirates of 130 patients with newly diagnosed carcinoma of the cervix uteri for the presence of cytokeratin(CK)-positive cells from May 1994 to January 2001. We used a quantitative immunoassay with the monoclonal anti-CK antibody A45-B/B3 and evaluated 2 x 10(6) bone marrow cells per patient. Patients were followed prospectively for a median of 43 (range, 1-85) months.

RESULTS

Isolated tumor cells were found in the bone marrow of 38 patients (29%). The presence of ITC did not correlate with the International Federation of Gynecology and Obstetrics (FIGO) tumor stage (P = 0.61), pelvic and paraaortal lymph node involvement (P = 0.41), histopathologic grading (P = 0.67), the histologic type of the carcinoma (P = 0.93), invasion of lymph nodes (P = 0.93) and blood vessels (P = 0.92), or with menopausal status (P = 0.17). The bone marrow status at the time of primary diagnosis did not correlate with the overall survival as estimated by Kaplan-Meier analysis (P = 0.30). However, distant metastases occurred in 5% of the patients (n = 5) with negative bone marrow status and in 15% of the patients (n = 6) with positive bone marrow status (P = 0.054). The median distant disease-free survival period was 78 months (95% confidence interval 73-82) in patients with negative bone marrow status and 72 months (95% CI 61-82) in patients with positive bone marrow status (P = 0.051). Multivariate analysis revealed the presence of ITC as a significant, independent risk factor for the subsequent development of distant metastases (relative risk 3.6, P = 0.046).

CONCLUSION

Despite the locoregional predominance of cervical carcinoma at the time of primary diagnosis, the presence of ITC in the bone marrow indicates an increased risk for the development of distant metastases. This information may prove useful to stratify patients for systemic treatment.

The significance of immunohistochemically demonstrated nodal micrometastases in patients with squamous cell carcinoma of the head and neck

OBJECTIVES/HYPOTHESIS

Patients with primary squamous cell carcinoma of the head and neck have a relatively high risk of occult lymph node metastases. Pathological demonstration of these metastases may be difficult, and the detection of such occult metastases may identify patients who are at an increased risk for early recurrence or reduced survival. Immunohistochemistry may be applied in the identification of occult metastases that may be missed on routine (H&E) histological examination. The aim of the study is to determine the prevalence and prognostic significance of immunohistochemically identified micrometastases in squamous cell carcinoma of the head and neck.

STUDY DESIGN

A retrospective analysis of neck dissection specimens having no evidence of metastatic disease.

METHODS

Lymph nodes from neck dissections performed on 10 patients with squamous cell carcinoma of the head and neck without conventional histological evidence of nodal metastases were subsequently stained for cytokeratins by the monoclonal antibody cocktail AE1/AE3 to detect micrometastases.

RESULTS

Occult micrometastases were found in the lymph nodes 5 of 10 patients examined. There was no association between the site of primary tumor, or T tage, and the presence of occult metastases. Three of five patients found to have occult metastases developed recurrence in the neck, whereas only one of five patients with no evidence of micrometastases had regional recurrence. There was no significant discrepancy in the patient survival rate.

CONCLUSIONS

Metastatic tumor cells are frequently present in lymph nodes, even in patients without histological evidence of nodal metastases by conventional methods. The presence of micrometastases may identify patients at increased risk for recurrence and may indicate poorer prognosis. The true clinical significance of these occult metastases will be determined by a long-term follow-up.

Refined mapping of Naegeli-Franceschetti- Jadassohn syndrome to a 6 cM interval on chromosome 17q11.2-q21 and investigation of candidate genes

Naegeli-Franceschetti-Jadassohn syndrome and dermatopathia pigmentosa reticularis are autosomal dominant ectodermal dysplasias characterized by the absence of dermatoglyphics, reticulate hyper pigmentation of the skin, hypohidrosis, and heat intolerance. Palmoplantar keratoderma, nail dystrophy, and enamel defects are common in Naegeli-Franceschetti-Jadassohn syndrome, whereas diffuse alopecia is only seen in dermatopathia pigmentosa reticularis. We studied a large Swiss family with Naegeli-Franceschetti-Jadassohn syndrome originally described by Naegeli in 1927 and assessed linkage to chromosome 17q, which was proposed to harbor the Naegeli-Franceschetti-Jadassohn syndrome gene. Our results considerably narrow the Naegeli-Franceschetti-Jadassohn syndrome gene region from 27 cM to 6 cM flanked by D17S933 and D17S934 with a maximum multipoint LOD score of 2.7 at marker locus D17S800. In addition, we studied a small family with dermatopathia pigmentosa reticularis, and our linkage data suggest that dermatopathia pigmentosa reticularis may map to the same chromosomal region. The Naegeli-Franceschetti-Jadassohn syndrome critical interval spans approximately 5.4 Mb and contains a minimum of 45 distinct genes. We scrutinized 13 new prime candidates in addition to five genes previously examined, established the genomic organization of 10 of these genes, and excluded all of them by mutation analysis. Moreover, we identified a cDNA (KRT24) encoding a new keratin protein that bears high similarity to the type I keratins and displays a unique expression profile. No pathogenic mutations were identified in this novel gene either, however. In summary, our results substantially refine the Naegeli-Franceschetti-Jadassohn syndrome region and will aid in identifying a gene that is critical for ontogenesis of multiple ectodermal tissues.

Clinical significance of occult micrometastases in axillary lymph nodes in "node-negative" breast cancer patients

The most important subgroup of breast cancer patients for whom reliable prognostic indicators are needed is women without axillary lymph node metastases. We evaluated the clinical significance of occult micrometastases in axillary lymph nodes in 148 consecutive "node-negative" breast cancer patients. The median age of the patients at surgery was 52 years and the median follow-up period after surgery was 98.5 months. Occult micrometastases were detected in 21 of 148 patients (14.2%) by means of immunohistochemical analysis using AE1 / 3 antibody and a single unstained section after routine histopathological examination. Log-rank tests indicated that the 7-year disease-free survival (DFS) and overall survival (OS) rates by Kaplan-Meier methods were significantly better in patients without occult micrometastases than in patients with occult micrometastases [DFS, 93% versus 71% (P = 0.0009); OS, 96% versus 76% (P = 0.0001)]. According to Cox's multivariate analysis, the presence of occult micrometastases had the most significant effect on DFS (P = 0.0053) and OS (P = 0.0035). These findings suggest that the presence of occult micrometastases is an independent and significant predictor of clinical outcome, and that their immunohistochemical detection after routine histopathological examination is useful for selecting the "node-negative" breast cancer patient subgroup at high risk for relapse and death.

Distribution of lymph node micrometastasis in pN0 well-differentiated thyroid carcinoma

BACKGROUND

The role of lymph node dissection in the treatment of differentiated thyroid carcinoma remains controversial, and the benefit of therapy is debatable. This study was designed to identify the precise localization of lymph node micrometastases (LNMM) and map their cervical involvement in relation with the tumor location within the thyroid gland.

METHODS

A total of 2551 cervical lymph nodes were obtained from 80 patients with well-differentiated thyroid cancer. They were diagnosed as clear lymph nodes by hematoxylin and eosin stain and then examined immunohistochemically with cytokeratins (AE1/AE3) for evidence of micrometastases.

RESULTS

Forty-two patients out of 80 (53%) had LNMM. Forty-eight patients (60%) had the tumor confined to only one third of 1 of the 2 lobes of the thyroid gland or isthmus. The frequencies and locations of LNMM in patients were 50% (3/6) in the deep upper cervical nodes, with tumors localized in the upper third; 31% (5/16) in the paraglandular nodes, with tumors affecting the middle third; 63% (12/19) in the paratracheal nodes, with tumors affecting the lower third of the thyroid lobe; and 71% (5/7) in the pretracheal nodes in the isthmus-located tumor. All the LNMM occurred on the ipsilateral side of the tumor.

CONCLUSIONS

When thyroid carcinoma is located in the upper third of the thyroid lobe, the LNMM are found in the direction of upward lymphatic flow. When the tumor is located in the lower third or isthmus, LNMM are directed downward. In addition, early thyroid carcinoma micrometastases do not cross the midline but remain on the ipsilateral side of the tumor.

Micrometastases in the cervical lymph nodes in esophageal squamous cell carcinoma

Few studies have investigated the presence of lymph node micrometastases (MM) in the cervical region of patients with esophageal squamous cell cancer. The present study examines the presence of cervical MM and attempts to determine a way to predict the occurrence and site of such micrometastases. A total of 2203 cervical lymph nodes and 118 mediastinal recurrent nerve nodes obtained from 86 patients with esophageal carcinoma were examined immunohistochemically using cytokeratins. Cervical lymph nodes and mediastinal recurrent nerve nodes metastases were detected histologically in 33 and 41 of the 86 patients respectively. Cervical lymph node and mediastinal recurrent nerve node MM were immunohistochemically detected in 16 (18.6%) and 6 (7.0%) patients respectively. Of these 16 patients with cervical MM, seven were found to have lymph node metastases in different cervical regions, whereas cervical MM only were detected in nine patients. Among the former group of patients, five were diagnosed by ultrasound examination as having cervical lymph node metastases. Mediastinal recurrent nerve node metastases and MM correlated with the presence of cervical MM in all but one patient. Cervical lymph node metastasis, including micrometastasis, can be predicted by preoperative ultrasonography and the routine histologic examination of mediastinal recurrent nerve nodes.

Micrometastases in non-small cell lung cancer (NSCLC)

Early metastasis is a well-known feature of poor prognosis in potentially resectable non-small cell lung cancer (NSCLC). However, a significant number of lymph node-negative patients die early of metastatic disease. Therefore, it has to be assumed that in some patients an early tumor cell dissemination has occurred which is clearly underestimated by current staging procedures. Recently, it has been shown, that an early dissemination of individual carcinoma cells to regional lymph nodes or bone marrow can be detected by using sensitive immunocytochemical techniques with monoclonal antibodies against epithelium-specific proteins. The incidence of immunohistochemically positive patients varies between 30 and 70% depending on the type of primary tumor, the immunohistochemical staining procedure used and especially on the primary monoclonal antibody. The detection of disseminated tumor cells in lymph nodes or bone marrow by immunocytochemistry is associated with a poorer prognosis in lung cancer. In conclusion, the immunohistochemical detection of disseminated tumor cells in lymph nodes can help to obtain a more exact identification of patients with an unfavorable prognosis. Whether the identified patients will gain from an adjuvant therapy, has to be evaluated in further studies.

Cytokeratin immunostaining patterns of benign, reactive lymph nodes: applications for the evaluation of sentinel lymph node specimen

The use and interpretation of cytokeratin (CK) immunostains of sentinel lymph node specimens for breast carcinoma remain controversial. Variable immunoreactivity with anti-CK antibodies and CK-positive interstitial reticulum cells may complicate interpretation. The authors examined a series of reactive lymph nodes selected from patients without a history of malignancy. To demonstrate potential diagnostic pitfalls, three different CK antibody combinations were studied to characterize the immunostaining patterns. Formalin-fixed sections of lymph nodes were immunostained with a labeled streptavidin-biotin method using a DAKO autostainer. The anti-CK antibody preparations evaluated were AE1/AE3, CAM 5.2, and an in-house-prepared CK cocktail composed of 7 antibodies. The authors observed that up to 10% of cells in benign, reactive lymph nodes may be immunoreactive with anti-CK antibodies. AE1/AE3 stained 2 of 20 cases with rare immunoreactive reticulum cells, whereas CAM 5.2 and the CK cocktail immunostained cells in 85% of cases with reticulum cells in sinuses and the paracortex. Rare positive to 2+ cells were present in a similar distribution with these two antibodies. Careful interpretation of CK immunostaining of sentinel lymph node biopsies is essential, as is awareness of the presence of CK-positive native reticulum cells, to avoid confusion with single cells of metastatic carcinoma.

Reverse-transcriptase polymerase chain reaction of the maspin gene in the detection of bone marrow breast carcinoma cell contamination

BACKGROUND

Maspin is a molecular marker used for the detection of contaminating breast carcinoma (BC) cells in peripheral blood and lymph nodes. However, its specificity has been questioned recently. The objective of this study was to verify the specificity of this marker and to determine the incidence of positive bone marrow results in patients with BC who are eligible for high-dose chemotherapy (HDT) both in early and advanced disease stages and before and after treatment.

METHODS

Bone marrow specimens from 41 patients with BC as well as from 35 normal volunteers and 17 patients with hematologic tumors were examined for maspin transcript expression by a modified nested reverse transcriptase-polymerase chain reaction technique.

RESULTS

Maspin transcript was found in all normal and neoplastic breast tissues and in none of the 35 normal bone marrow specimens (specificity, 100%; 95% confidence interval, 90-100%). However, the transcript was found in 40% of the bone marrow samples from patients with hematologic malignancies. Thus, this marker appears very specific for discriminating between normal controls and patients with BC, but it cannot be considered disease specific. Among patients with BC, bone marrow was positive for the maspin transcript in 32% of patients with early-stage disease and in 75% of patients with metastatic disease before chemotherapy. After treatment, in 75% of patients with early-stage disease and in 50% of patients with metastatic disease, the bone marrow results became maspin negative.

CONCLUSIONS

On the basis of the current data, although it is not disease specific, maspin is a reliable marker for detecting bone marrow molecular disease in patients with BC and should be considered for prospective studies as a prognostic indicator and as an assay for monitoring residual disease.

Reticulum cell sarcoma of lymph node with mixed dendritic and fibroblastic features

We report a case of clinically aggressive reticulum cell sarcoma with mixed follicular dendritic cell (FDC) and fibroblastic reticular cell (FRC) features. Histologically, the tumor was confined to lymph nodes occurring as a multifocal epithelioid and spindle cell proliferation with appreciable mitotic rate and numerous admixed non-neoplastic B-cells. Ultrastructural examination revealed elongated cells with prominent nucleoli, interdigitating cell processes and frequent desmosomes. These features are typical of FDC sarcoma. However, immunohistochemical stains showed no expression of antigens characteristic of FDCs, including CD21, CD23 and CD35. Cytogenetic characterization of this tumor, by conventional G-banding and multicolor spectral karyotyping, revealed multiple clonal chromosomal aberrations, including del(X)(p11.4) and add (21)(p11.2). Gene expression analysis by cDNA microarray of RNA obtained from short-term tumor cultures revealed high-level expression of a set of genes (including PDGF receptor-alpha and -beta, certain metalloproteinases, and CD105) that were also highly expressed in cultures of nodal FRC cultured from non-neoplastic lymph nodes. We propose that this tumor represents a nodal sarcoma with intermediate differentiation between FDCs and FRCs. This case adds to the diversity of tumors that may arise from lymph node stroma and supports a possible relationship between the FDC and FRC lineages.

The perifollicular and marginal zones of the human splenic white pulp : do fibroblasts guide lymphocyte immigration?

We investigate the white pulp compartments of 73 human spleens and demonstrate that there are several microanatomical peculiarities in man that do not occur in rats or mice. Humans lack a marginal sinus separating the marginal zone (MZ) from the follicles or the follicular mantle zone. The MZ is divided into an inner and an outer compartment by a special type of fibroblasts. An additional compartment, termed the perifollicular zone, is present between the follicular MZ and the red pulp. The perifollicular zone contains sheathed capillaries and blood-filled spaces without endothelial lining. In the perifollicular zone, in the outer MZ, and in the T cell zone fibroblasts of an unusual phenotype occur. These cells stain for the adhesion molecules MAdCAM-1, VCAM-1 (CD106), and VAP-1; the Thy-1 (CD90) molecule; smooth muscle alpha-actin and smooth muscle myosin; cytokeratin 18; and thrombomodulin (CD141). They are, however, negative for the peripheral node addressin, the cutaneous lymphocyte antigen, CD34, PECAM-1 (CD31), and P- and E-selectin (CD62P and CD62E). In the MZ the fibroblasts are often tightly associated with CD4-positive T lymphocytes, whereas CD8-positive cells are almost absent. Our findings lead to the hypothesis, that recirculating CD4-positive T lymphocytes enter the human splenic white pulp from the open circulation of the perifollicular zone without crossing an endothelium. Specialized fibroblasts may attract these T cells and guide them into the periarteriolar T cell area.

Comparative analysis of micrometastasis to the bone marrow and lymph nodes of node-negative breast cancer patients receiving no adjuvant therapy

PURPOSE

In node-negative patients, of whom up to 30% will recur within 5 years after diagnosis, markers are still needed that identify patients at high enough risk to warrant further adjuvant treatment. In the present study we analyzed whether a correlation exists between microscopic tumor cell spread to bone marrow and to lymph nodes and attempted to determine which route is clinically more important.

PATIENTS AND METHODS

According to a prospective design, bone marrow aspirates and axillary lymph nodes of level I (n = 1,590) from 150 node-negative patients with stage I or II breast cancer were analyzed immunocytochemically with monoclonal anticytokeratin (CK) antibodies. We investigated associations with prognostic factors and the effect of micrometastasis on patients' prognosis.

RESULTS

CK-positive cells in bone marrow aspirates were present in 44 (29%) of 150 breast cancer patients, whereas only 13 patients (9%) had such positive findings in lymph nodes; simultaneous microdissemination to bone marrow and lymph nodes was seen in merely two patients. No correlation of bone marrow micrometastases with other risk factors was assessed. Reduced 4-year distant disease-free and overall survival were each associated with a positive bone marrow finding (P =.032 and P =.014, respectively) but not with lymph node micrometastasis. Multivariate analysis revealed an independent prognostic effect of bone marrow micrometastasis on survival, with a hazards ratio of 6.1 (95% confidence interval, 1.2 to 31.3) for cancer-related death (P =.031) in our series.

CONCLUSION

Immunocytochemical detection of micrometastatic cells in bone marrow but not in lymph nodes is an independent prognostic risk factor in node-negative breast cancer that may have implications for surgery and stratification into adjuvant therapy trials.

Detection and relevance of immunohistochemically identifiable tumor cells in lymph nodes

Lymph node metastasis is a well-known feature of poor prognosis in potentially resectable solid epithelial tumors. However, a significant number of apparently lymph node negative patients die early of metastatic disease. Therefore, it has to be assumed that in some patients an early tumor cell dissemination has occurred which is clearly underestimated by current staging procedures. Recently, it has been shown, that an early dissemination of individual carcinoma cells to regional lymph nodes can be detected by using sensitive immunocytochemical techniques with monoclonal antibodies against epithelium-specific proteins. The incidence of immunohistochemically positive patients varies between 12% and 70% depending on the type of primary tumor, the immunohistochemical staining procedure used, and especially on the primary monoclonal antibody. The detection of disseminated tumor cells in lymph nodes by immunocytochemistry is associated with a poorer prognosis in different types of epithelial tumors such as lung cancer or esophageal cancer. The immunocytochemical method might also be useful in the detection of occult tumor cells in sentinel lymph nodes. In conclusion, the immunohistochemical detection of disseminated tumor cells in lymph nodes can help to obtain a more exact identification of patients with an unfavorable prognosis. Whether the identified patients will gain from an adjuvant therapy has to be evaluated in further studies.

Occult tumor cells in bone marrow of patients with locoregionally restricted ovarian cancer predict early distant metastatic relapse

PURPOSE

Based on conventional tumor staging, primary ovarian cancer is viewed as an intraperitoneal disease that rarely spreads to extraperitoneal organs. However, autopsy studies reveal a much higher rate of occult metastasis, indicating that extraperitoneal spread occurs with much greater frequency than previously appreciated. Consequently, we investigated the incidence of early hematogenous dissemination and its association with distant disease-free and overall survival.

PATIENTS AND METHODS

Bone marrow aspirates from 108 patients newly diagnosed with International Federation of Gynecology and Obstetrics stage I to III ovarian cancer were prospectively analyzed with the novel anti-cytokeratin (CK) antibody A45-B/B3. We investigated the frequency of CK-positive tumor cells in bone marrow and their effect on prognosis in relation to established risk factors for tumor progression.

RESULTS

Tumor cells in bone marrow were detected in 32 (30%) of 108 patients. A CK-positive finding was unrelated to established risk parameters, except for poor nuclear grading of the primary tumor. At a median follow-up of 45 months (range, 12 to 77 months), the presence of occult metastatic cells in bone marrow was associated with the occurrence of clinically overt, extraperitoneal (predominantly extraskeletal) distant metastasis (relative risk [RR], 16.5; 95% confidence interval [CI], 6.2 to 56.9; P < .0001) and death from cancer-related causes (RR, 2.3; 95% CI, 1.2 to 4.3; P = .01). Multivariate analysis identified a positive bone marrow finding as an independent prognostic factor of reduced distant disease-free survival for all patients (RR, 13.8; 95% CI, 5.4 to 52.9; P < .0001) and for the 64 stage R0-1 patients (RR, 7.3; 95% CI, 1.5 to 56.8; P = .0021).

CONCLUSION

Our data signal that hematogenous dissemination of tumor cells occurs early and throughout all stages of ovarian cancer. The clinical significance of our findings is supported by the unfavorable prognosis in association with the presence of occult metastatic cells, especially in those patients who received an effective locoregional therapy.

Clinical relevance of occult metastatic cells in the bone marrow of patients with different stages of breast cancer

Data are emerging about the prognostic relevance of occult metastatic cells in the bone marrow of patients with various solid tumors. Discrepancies among different studies on the prognostic relevance of isolated tumor cells may be caused by tumor cell heterogeneity and the use of different immunoassays. There is increasing evidence that validated anticytokeratin antibodies (e.g., A45-B/B3) represent the present standard for the detection of isolated tumor cells. This immunocytochemical assay allows the identification of patients with occult tumor cell dissemination that cannot be identified by conventional screening methods in tumor staging. According to recent studies, these patients are at higher risk for subsequent development of distant metastases and might therefore benefit from early systemic therapy. At advanced stages of the disease, the micrometastatic tumor load after adjuvant therapy, or at the time of emerging recurrences, appears to reflect the tumor's ability to progress. Therapeutic monitoring and cell-cycle independent antibody-based therapy are among possible implications of this new, promising diagnostic tool. The present review also focuses on state of the art, reliable detection methods of occult metastatic cells in the bone marrow of breast cancer patients and on the prognostic relevance of these cells at different stages of the disease.

Undesirable cytokeratin immunoreactivity of native nonepithelial cells in sentinel lymph nodes from patients with breast carcinoma

CONTEXT

Use of cytokeratin immunohistochemistry on histologically negative sentinel lymph nodes (SLNs) in patients with breast carcinoma has been shown to be efficient in detecting false-negative nodes. Several recent studies have shown that micrometastases detected by immunohistochemistry constitute an independent predictor of disease-free period and overall survival for breast cancer patients. It has been demonstrated that the fibroblastic type of reticulum cells in lymph nodes also express cytokeratin, and unawareness of such cytokeratin reactivity in SLNs could result in difficulty in the interpretation of the results of immunohistochemistry.

OBJECTIVES

To study the incidence of undesirable cytokeratin reactivity in reticulum cells and other native nonepithelial cells of SLNs and to compare the immunoreactivity of 3 commonly used cytokeratin antibodies (AE1/AE3, pancytokeratin [pan-CK], and CAM5.2).

DESIGN

Immunohistochemistry with pan-CK, AE1/AE3, and CAM5.2 antibodies was performed on paraffin sections of SLNs from patients with breast cancer. Correlation of undesirable cytokeratin reactivity with size and metastatic status of the SLNs was also analyzed.

PATIENT MATERIAL

Paraffin sections of 84 SLNs from 38 consecutive patients with breast cancer in our tertiary-care, teaching hospital.

RESULTS

Cytokeratin reactivity was found in reticulum cells and plasma cells in 29 (35%) and 9 (10%) of the 84 SLNs, respectively, with pan-CK and CAM5.2 but not with AE1/AE3 (P <.001). The presence of cytokeratin-positive reticulum cells did not correlate with the size and metastatic involvement of the SLNs.

CONCLUSIONS

The incidence of undesirable keratin reactivity in SLNs from breast cancer patients could be limited by using an AE1/AE3 antibody cocktail. The AE1/AE3 antibody cocktail is a sensitive epithelial marker and appears to be more specific in recognizing epithelial cells in SLNs.

Sentinel Lymph Node Biopsy in Breast Cancer

One of the most important prognostic indicators in patients with breast cancer is axillary lymph node status. Sentinel lymph node (SLN) biopsy has emerged as a potential alternative to routine axillary dissection in clinically node-negative early breast cancer. This procedure requires a specialized but multidisciplinary approach utilizing the surgeon, nuclear radiologist and pathologist. SLN biopsy allows adequate assessment of the axillary nodal status in patients with early breast cancer, with minimal—if any—morbidity. Blue dye and lymphoscintigraphy are complementary techniques, and the success rate is maximized when the two methods are used together. Focused histopathologic examination on one or two lymph nodes most likely to contain metastases [SLN(s)], using serial sectioning and immunohistochemical techniques, allows an improved staging to be performed. Detection of metastases on SLN(s) is not only a prognostic indicator, but it also dictates whether the patient should receive further surgery and adjuvant chemotherapy. Until data regarding the long-term results of the SLN biopsy are available, this method should be considered investigational and be performed by surgeons experienced in this technique to achieve a failure rate of less than 2 per cent.

Pitfalls in the detection of disseminated non-hematological tumor cells

There is not yet a consensus on the reliability of the methods that should be used for the detection of rare disseminated tumor cells from non-hematological malignancies. In this review, we will discuss the advantage and drawbacks of the classical approach of immunocytochemistry and the molecular detection by reverse transcriptase polymerase chain reaction (RT-PCR). The interpretation of the biological significance of circulating tumor cells and the pitfalls of the detection techniques are the main causes of discrepancy between the conclusions of different tumor-cell detection (TCD) studies.

A case of keratin-positive acute myeloid leukemia: a possible role for cytokeratin 19 as a specific epithelial marker

A patient with relapsed acute myelomonocytic leukemia (AML, FAB M4) developed skin infiltration by leukemic blasts. On immunochemistry, the blasts showed "bot" positive cytoplasmic staining for cytokeratins AE1/AE3 and CAM 5.2, resembling the pattern seen in Merkel cell carcinoma of skin. However, the blasts were positive for myeloid markers and negative for cytokeratin 19 and chromogranin. Aberrant immunochemical staining can lead to misdiagnosis unless a panel of antibodies of known specificity is used in tumor diagnosis, and the clinical context is taken into account. The possible role of cytokeratin 19 as a more specific marker for epithelia than keratin cocktails is discussed.

Diffuse-type giant cell tumor: clinicopathologic and immunohistochemical analysis of 50 cases with extraarticular disease

The clinical and pathologic features of 50 cases of diffuse-type tenosynovial giant cell tumor (D-TGCT), also known as extraarticular pigmented villonodular tenosynovitis (PVNTS), are presented. Patients' ages ranged from 4 to 76 years (median, 41 yrs), with a slight female predominance (28 women, 22 men). By definition, all lesions presented as predominant soft tissue masses, with or without an associated articular component. Tumor sites included the wrist (9 cases), knee (8 cases), thigh and foot (6 cases each), finger (5 cases), ankle (3 cases), hand, elbow, toes, buttock, paravertebral region (2 cases each), lower leg, sacrococcygeal area, and retroperitoneum; 27 cases were described as entirely extraarticular. Tumors showed infiltrative margins and, in most cases, a sheet-like growth pattern. Striking variation in the number of osteoclast-like giant cells, foamy cells, amount of hemosiderin, and in the degree of stromal hyalinization were responsible for a wide morphologic spectrum. In addition to the predominant histiocyte-like cells, we identified in most cases a subpopulation of large dendritic, desmin-positive cells showing characteristic, but potentially misleading, cytologic features, including abundant eosinophilic cytoplasm, large vesicular nuclei, paranuclear eosinophilic inclusions, and occasional nuclear inclusions. Follow-up information was available for 24 patients, with a duration ranging from 6 months to 30 years (mean, 55 mos). Local recurrence occurred in eight cases (33%), between 4 months and 6 months after surgery (median, 15 mos) and was repeated in five cases; recurrence did not appear to correlate with morphologic parameters. Six cases showed atypical histologic features and four of these contained areas of sarcomatous change. Among the latter, one of three cases with available follow up developed pulmonary metastases and died after 35 months. In addition, one histologically benign lesion gave rise, after two local recurrences, to inguinal and iliac lymph node metastases. Despite this exceedingly uncommon event, we think most cases of D-TGCT are best regarded as benign but locally aggressive neoplasms with significant recurrent potential and should be treated, when possible, by wide excision. Atypical features such as increased mitotic activity, necrosis, spindling of the mononucleate cells, and cytologic atypia are not indicative of malignancy when present individually. This study also confirms the existence of malignant tenosynovial giant cell tumors, some of which are characterized by aggressive behavior.

Cytokeratin-positive cells in the bone marrow and survival of patients with stage I, II, or III breast cancer

BACKGROUND

Cytokeratins are specific markers of epithelial cancer cells in bone marrow. We assessed the influence of cytokeratin-positive micrometastases in the bone marrow on the prognosis of women with breast cancer.

METHODS

We obtained bone marrow aspirates from both upper iliac crests of 552 patients with stage I, II, or III breast cancer who underwent complete resection of the tumor and 191 patients with nonmalignant disease. The specimens were stained with the monoclonal antibody A45-B/B3, which binds to an antigen on cytokeratins. The median follow-up was 38 months (range, 10 to 70). The primary end point was survival.

RESULTS

Cytokeratin-positive cells were detected in the bone marrow specimens of 2 of the 191 control patients with nonmalignant conditions (1 percent) and 199 of the 552 patients with breast cancer (36 percent). The presence of occult metastatic cells in bone marrow was unrelated to the presence or absence of lymph-node metastasis (P=0.13). After four years of follow-up, the presence of micrometastases in bone marrow was associated with the occurrence of clinically overt distant metastasis and death from cancer-related causes (P<0.001), but not with locoregional relapse (P=0.77). Of 199 patients with occult metastatic cells, 49 died of cancer, whereas of 353 patients without such cells, 22 died of cancer-related causes (P<0.001). Among the 301 women without lymph-node metastases, 14 of the 100 with bone marrow micrometastases died of cancer-related causes, as did 2 of the 201 without bone marrow micrometastases (P<0.001). The presence of occult metastatic cells in bone marrow, as compared with their absence, was an independent prognostic indicator of the risk of death from cancer (relative risk, 4.17; 95 percent confidence interval, 2.51 to 6.94; P<0.001), after adjustment for the use of systemic adjuvant chemotherapy.

CONCLUSIONS

The presence of occult cytokeratin-positive metastatic cells in bone marrow increases the risk of relapse in patients with stage I, II, or III breast cancer.

Cytokeratin-Positive Malignant Tumors With Reticulum Cell Morphology

Cytokeratin-positive interstitial reticulum cells (CIRCs) have been described as a subset of fibroblastic reticulum cells (FBRCs) normally found in lymph nodes, the spleen, and tonsils. Although tumors derived form other reticulum (dendritic) cells, specifically follicular dendritic cells, interdigitating dendritic cells, and cytokeratin-negative FBRCs, have been well documented and are now accepted, this is not the case for tumors of CIRCs. A possible reason for this failure is the difficulty in distinguishing them from other tumors, particularly carcinoma. We report three cases of cytokeratin-positive malignant tumors with a reticulum cell morphology: two located in the mediastinum and one in the soft tissue in the proximal forearm. All cases coexpressed vimentin, and one case coexpressed smooth muscle actin and desmin, resulting in a phenotype similar to that of some normal CIRCs. Although metastatic carcinoma from an occult or regressed primary tumor cannot be excluded completely, we raise the possibility of a CIRC origin for these cases.

Angiomatoid "malignant" fibrous histiocytoma: a clinicopathologic study of 158 cases and further exploration of the myoid phenotype

Angiomatoid "malignant" fibrous histiocytoma (AMFH) has been considered to be a low-grade sarcoma of childhood, and, with its fibrous pseudocapsule, angiomatoid change, dense lymphoplasmacytic response, and proliferation of spindled or round cells, has been classified as a fibrohistiocytic neoplasm. We wanted to study the clinicopathologic and immunophenotypic features of a large number of these tumors and to especially further explore their myoid differentiation. Cases coded as AMFH from 1979 to 1995 were retrieved from the Soft Tissue Registry of the AFIP. Only cases that met the criteria for AMFH by light microscopy were included, a total of 158 cases. Immunohistochemistry was obtained on 98 cases. Clinical history on 92% of all cases revealed a gender ratio of 1.3 females: males, age range of 2 to 71 years, median size of 2.0 cm, and a distribution of extremities > trunk > head and neck, with 66% lesions occurring in areas of normal lymphoid tissue. All tumors with available margins were well-circumscribed. Eighty percent of cases had some degree of lymphoplasmacytic infiltration; 50% cases had pseudovascular spaces filled with blood. Fifty-two percent had predominantly round cell morphology; 48% had a predominantly spindle cell pattern. Desmin positivity was noted in 51% cases and occurred in both predominantly round cell and spindle cell tumors. Most of the desmin-positive cases with adjacent lymphoid infiltrate (67%) showed scattered similar, desmin-positive cells in the surrounding lymphoid infiltrate, adjacent to the tumor. Muscle-specific and smooth-muscle actins were seen in 14% cases. Heavy-caldesmon was strongly positive in 3%, and calponin was focally positive in 73% and extensively positive in 12% cases. MyoD1, myoglobin, and myogenin (myf4) were negative in all tumors studied. Forty-five percent of cases were positive for CD99; 52% of these had round cell morphology. Fifteen percent of cases were positive for KP-1. All tumors were positive for vimentin and negative for CD21, CD35, S100 protein, CD34, keratins 8/18, and lysozyme. Clinical follow-up on 86 patients indicated that only 1 patient was alive with a local nodal metastasis (1% frequency of metastasis) within 1 year, and 2 others had local recurrence, all over a mean follow-up period of 6 years. The myoid, primarily myofibroblastic, phenotype of these lesions is supported by desmin, calponin, and occasional actin positivity. The occasional heavy-caldesmon and smooth muscle actin additionally suggest rare smooth muscle phenotype; however, lack of skeletal muscle markers indicate no relationship of AMFH to skeletal muscle tumors. The resemblance of these lesions to lymph nodes, clinically and morphologically, the finding of similar desmin positive cells in the adjacent lymphoid infiltrate, and the fact that 66% cases were found in sites of normal lymphoid tissue raise the possibility that some of these lesions may arise from or be related to myoid cells of lymphoid tissue. AMFH has an almost invariably benign behavior, but the 1% metastatic rate warrants its classification as low-grade "malignant." The predominantly round cell, CD99-positive and desmin positive AMFH cases, respectively, should not be confused with Ewing's sarcoma/PNET or rhabdomyosarcoma, respectively.

Benign mesothelial cells in mediastinal lymph nodes

Inclusions of benign tissues in lymph nodes are most often aberrant glandular tissue, including endosalpingiosis, the thyroid, parotid, breast, and pancreas. Nonglandular inclusions are rare and include nevus cells and decidua. Mesothelial cells in lymph nodes are exceedingly rare; only eight cases have been reported in mediastinal lymph nodes and three cases in abdominal lymph nodes. The incidence of benign mesothelial cells in mediastinal lymph nodes in patients with a history of pericarditis or pleuritis is reported in this study. A retrospective search showed eight cases with removal of mediastinal lymph nodes in the absence of neoplasm. Hematoxylin and eosin-stained sections were examined in all cases. Immunohistochemical stains for CAM 5.2 were performed in all cases, and stains for AE1/AE3, Ber-EP4, carcinoembryonic antigen, Leu-M1, B72.3, and S-100 were performed in one case. CAM 5.2-positive cells with features of mesothelial cells were present in five of eight cases. In all cases, the cells were present in nodal sinuses and appeared as single cells or small clusters. The cells were missed on routine hematoxylin and eosin sections in all cases but one, in which they were numerous and mimicked metastatic carcinoma. Malignancy was not found in any of the cases preoperatively, at the time of surgery, or during the follow-up period. Benign mesothelial cells may embolize to regional lymph nodes in pleuritis or pericarditis. In most cases, these cells are few and undetectable on routine sections. Rarely, hyperplastic mesothelial cells may be present and must be distinguished from metastatic carcinoma, mesothelioma, and melanoma.