Characterization of foam cells in nipple aspirate fluid.

Foam cells with abundant vacuolated cytoplasm are prominent in most samples of spontaneous nipple discharge, nipple aspirate fluid, and ductal lavage. Although several investigators have attempted to characterize these cells, there is no consensus about whether these cells are derived entirely from macrophages or from both ductal epithelial cells and macrophages. Using immunocytochemical methods, we studied 20 paired specimens of nipple aspirate fluid containing abundant foam cells obtained from the involved breast of women with in situ or invasive carcinoma and from the contralateral normal breast. We used a cocktail of anticytokeratin antibodies including AE1, AE3, and CAM5.2 and the macrophage marker KP1 (CD68). In addition, we examined samples by electron microscopy. The foam cells were consistently negative for cytokeratin and positive for CD68. In every case electron microscopy of these cells revealed irregular outlines with short cytoplasmic processes. The cytoplasm was abundant and contained numerous lysosomes, a small Golgi complex, lipid droplets, mitochondria, and short profiles of rough endoplasmic reticulum. There was no evidence, however, of cell junctions or tonofilaments. The immunocytochemical and electron microscopic findings of our study together clearly support a macrophage derivation for foam cells in nipple aspirate fluid.

Primary signet-ring cell carcinoma of lung: immunohistochemical study and comparison with non-pulmonary signet-ring cell carcinomas.

Signet-ring cell carcinoma (SRCC) of lung is a rare variant of pulmonary adenocarcinoma. In view of this rarity, the question of whether an SRCC is primary pulmonary or metastatic arises frequently because the majority of SRCCs seen in lung are metastatic tumors having arisen in stomach, colon, or breast. On routine histologic examination it is difficult to distinguish between pulmonary SRCC from SRCC metastasizing from other organs. Thyroid transcription factor-1 (TTF-1) is a homeodomain-containing transcription factor that is almost exclusively expressed in thyroid and pulmonary epithelial cells. TTF-1 expression has been demonstrated in various neoplasms of lung; however, the expression of TTF-1 in SRCCs has not been investigated so far. In the present study, using an immunoperoxidase staining procedure on paraffin sections, we investigated the expression of TTF-1, cytokeratin 7, cytokeratin 20, and villin (a specific marker expressed in tumors of the digestive tract, renal proximal tubules, and hepatic bile ducts) in 32 SRCCs from various organs (17 lung, 5 breast, 5 stomach, and 5 colon). Fourteen (82.4%) of 17 pulmonary SRCCs exhibited TTF-1 positivity, whereas none of the SRCCs of other organs were positive for TTF-1. A cytokeratin profile (CK7+/CK20-) was identified in 94.1% of pulmonary SRCC, and although it differed from the profile exhibited in colonic SRCCs (CK7-/CK20+), a similar profile was seen in breast SRCCs and some SRCCs arising in the stomach. Villin was identified in 29.4% of pulmonary SRCCs and 20% (one case) arising in the breast. Although the pattern of villin immunostaining exhibited by nondigestive tract SRCCs (cytoplasmic) differed from those of digestive tract SRCCs (membranous), distinguishing between the two groups based on their pattern of immunostaining alone would be difficult. The results of this study indicate that TTF-1 is expressed in a high percentage of pulmonary SRCCs and is very specific and that TTF-1 would be extremely valuable in distinguishing pulmonary SRCCs from those arising in other organs.

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.

Pulmonary granuloma caused by Pseudomonas andersonii sp nov.

Pulmonary granuloma is a common lesion for which gram-negative bacteria are rarely implicated as a cause. Hence, most physicians are unaware of this etiology. We isolated a gram-negative bacterium from a surgically resected pulmonary granuloma in a 42-year-old, nonimmunocompromised woman. Within the necrotizing granuloma, numerous organisms also were demonstrated by Gram stain, suggesting a cause-disease relationship. Characterization of the bacterium by sequence analysis of the 16S ribosomal gene, cellular fatty acid profiling, and microbiologic studies revealed a novel bacterium with a close relationship to Pseudomonas. We propose a new species for the bacterium, Pseudomonas andersonii. These results suggest that the differential diagnosis of a lung granuloma also should include this gram-negative bacterium as a potential causative agent, in addition to the more common infections caused by acid-fast bacilli and fungi. This bacterium was shown to be susceptible to most antibiotics that are active against gram-negative bacteria.

Low-grade (fibromatosis-like) spindle cell carcinoma of the breast.

Spindle cell carcinoma of the breast, a variant of metaplastic carcinoma, includes a wide spectrum of lesions with histomorphologic and nuclear features ranging from overtly malignant to mildly atypical. Spindle cell carcinomas with mildly atypical features may resemble fasciitis, fibromatosis, or myofibroblastic tumors and therefore are often misinterpreted as such. A recent study has suggested that spindle cell carcinomas with a dominant fibromatosis-like phenotype, unlike spindle cell carcinomas in general, have no propensity for distant metastasis and should be termed "tumors" rather than "carcinomas." To investigate the question of fibromatosis-like spindle cell breast carcinoma (FLSpCCs) metastatic potential, we studied cases of FLSpCC seen at the University of Texas M.D. Anderson Cancer Center between 1987 and 2000. Clinical, pathologic, and immunophenotypic features were reviewed, with emphasis on biologic behavior and predictors of clinical outcome. Our series included 24 women who ranged in age from 55 to 85 years (mean 66 years). Tumor size ranged from 1.0 to 5 cm (mean 2.8 cm). Most tumors were grossly well defined but had microscopic infiltrative borders. Tumors showed a dominant fibromatosis-like or myofibroblastic-like growth pattern with prominent collagenization. Inflammatory infiltrate was noted in the majority of tumors. Cytokeratin-positive cells were seen in all cases and usually appeared as cords or sheets of polygonal cells; isolated cytokeratin-positive cells were rare. In most tumors immunoreactivity for smooth muscle actin (SMA) was confined to the cytokeratin-negative cells. In five cases intense co-expression of cytokeratin and SMA was noted. None of the tumors showed immunoreactivity for smooth muscle heavy chain myosin, estrogen receptors, progesterone receptors, or HER-2/neu. Ki-67 expression was noted in fewer than 5% of tumor cells. Treatment consisted of local excision (seven cases) or modified radical mastectomy (13 cases). Treatment was unknown in four cases. In patients who underwent axillary nodal dissection, no lymph node metastases were found. Two of the six patients who underwent local excision developed local recurrence. Two patients who underwent modified radical mastectomy developed lung metastases within 2 years after the initial diagnosis. The metastatic tumors were histologically similar to the primary tumors. Our findings indicate that FLSpCCs have the potential for local recurrence and distant metastasis and should be treated accordingly. Because FLSpCCs may be underdiagnosed as benign, the use of immunohistochemical studies, especially for cytokeratins and SMA, is essential in the evaluation of any spindle cell proliferations of the breast.

Pancreatic acinar cell carcinoma.

Acinar cell carcinomas (ACCs) are rare neoplasms that represent less than 2% of all exocrine tumors of the pancreas. Although they occur more often in adults between the 5th and 7th decades of life, a few cases have been reported in children. Histologically, ACCs can resemble islet cell tumors, but they differ in their ultrastructural and immunohistochemical features. Although ACCs present a bland histology, they are highly malignant and the survival of patients with these tumors, even though better than that of those with ductal cell carcinomas, is generally poor.

Ciliated epithelia in the urethra: case report and literature review.

The presence of ciliated epithelial cells in the urethra has not been well recognized. Only two reports in the literature, both of which used scanning microscopy studies, have described this phenomenon. In this report, we illustrate the presence of scattered, ciliated epithelial cells in penile urethral biopsy specimens from a 38-year-old man with a history of bladder calculi and hematuria, by both light and transmission electron microscopy studies. The cilia in the urethra showed typical light microscopic and ultrastructural features of those seen in other organs. These ciliated cells are present in association with urothelial papilloma, condyloma acuminatum and acute inflammation of the urethra. These findings suggest that ciliated cells in the penile 0 urethra might be a consequence of metaplastic change of the urothelium, secondary to local stimulation or irritation.

Insulinoma with fibrillar inclusions and acinar cell elements.

Islet cell tumors associated with exocrine elements are rare. An insulinoma was removed from the head of the pancreas of a 33-year-old woman. Ultrastructural and immunohistochemical studies demonstrated that, in addition to the endocrine cells, the tumor had a small population of cells with an acinar cell morphology. Rare cells exhibiting both endocrine and exocrine features (amphicrine cells) were also identified. Another unusual finding in this case was the presence of a large number of intracytoplasmic filamentous inclusions that, even though they have been observed in other neoplasms, have not previously been reported in endocrine tumors of the pancreas. The demonstration of cells with mixed endocrine features supports the concept that both the endocrine and exocrine portions of the components of the pancreas have a common embryologic origin.

Localized (solitary) fibrous tumor of the pleura.

Clinical, light microscopic, ultrastructural, and immunocytochemical features of localized fibrous tumor of the pleura are reviewed. The differential diagnosis of the benign tumors can be uncomplicated, but atypical variants and malignant forms require the exclusion of other tumors included in the broad array of spindle cell neoplasms that can arise in or extend to a serosal surface. Electron microscopy is useful, but immunostaining procedures offer more extensive and reliable help in reaching the correct diagnosis. Tumors histologically similar to localized fibrous tumor of the pleura have been described in a number of extraserosal locations. Some localized fibrous tumors may be true fibromas, whereas the typical pleural tumor appears to arise from the subserosal mesenchymal cell and is composed of CD34-positive cells which are more primitive in their morphology than mature fibroblasts.

Acinar cell carcinoma of the pancreas.

Four cases of acinar cell carcinoma of the pancreas are reported. An acinar cell carcinoma can resemble an islet cell tumor by routine light microscopy but the two differ considerably in their fine structure and immunostaining properties. Although cells of both tumors contain numerous dense-core granules, their size ranges are different, and atypical forms occur in the acinar cell tumors, including elongated bodies filled with filaments. Many mitochondria-rough endoplasmic reticulum complexes were present in one tumor. In a liver metastasis, nests of endocrine cells were discovered amid the groups of acinar cells, and some of the endocrine granules contained rectangular cores.

Malignant fibrous histiocytoma: an ultrastructural perspective.

Malignant fibrous histiocytoma is a frequent diagnosis, but the relationship of the tumors to histologically similar soft tissue neoplasms is controversial. In this study, 157 examples representing the 4 main subtypes were reviewed by light microscopy and each tumor was studied with the electron microscope. Immunohistochemical stains were performed on 77 tumors. Electron micrographs on 100 fibrosarcomas were reviewed for comparison. Malignant fibrous histiocytomas often closely resemble fibrosarcomas at the ultrastructural level and differences between the two are generally of degree only. Evidence for true histiocytic differentiation was not found. The immunohistochemical results did not contradict the authors' impression from electron microscopy that malignant fibrous histiocytoma forms part of the histologic spectrum of tumors of fibroblasts.

Value of thyroid transcription factor-1 immunostaining in distinguishing small cell lung carcinomas from other small cell carcinomas.

The distinction between small cell lung carcinoma (SCLC) and small cell carcinomas of other sites is difficult by routine histology. Thyroid transcription factor-1 (TTF-1) is a homeodomain-containing transcription factor that is selectively expressed in thyroid and pulmonary epithelial cells. TTF-1 expression has also been demonstrated in adenocarcinomas of the thyroid and lung, and SCLC. However, the value of TTF-1 immunostaining in discriminating between SCLC and nonpulmonary small cell carcinomas has not been investigated. In the present study using an immunoperoxidase staining procedure on paraffin sections, we investigated the expression of TTF-1 and cytokeratin 20 (CK20), a marker that has previously been demonstrated in small cell carcinomas of the skin (Merkel cell carcinomas), in 82 small cell carcinomas from a wide variety of sites (28 lung, 18 skin, 12 gastrointestinal tract, 8 sinonasal, 5 bladder, 3 prostate, 3 uterine cervix, 2 thyroid, 2 salivary gland, and 1 pancreas). Twenty-seven (96%) of the 28 SCLCs were positive for TTF-1. Among the nonpulmonary small cell carcinomas, two tumors of the gastrointestinal tract, one of the bladder, and one of the uterine cervix exhibited TTF-1 positivity. Sixteen (89%) of the 18 Merkel cell carcinomas and one SCLC were CK20-positive. All other small cell carcinomas were negative for this marker. These results indicate that although TTF-1 is not a specific marker for SCLC, it may assist in distinguishing SCLC from some nonpulmonary small cell carcinomas, particularly Merkel cell carcinoma, especially when it is used in conjunction with CK20.

Brenner tumor of the ovary: a comparative immunohistochemical and ultrastructural study with transitional cell carcinoma of the bladder.

Because of a fancied light microscopic resemblance to transitional epithelium (urothelium), Brenner tumor (BT) of the ovary is commonly described as a transitional cell neoplasm. An inability to detect a great deal of similarity between the two at the ultrastructural level prompted this electron microscopic study comparing 3 benign Brenner tumors with normal urothelium and 6 transitional cell carcinomas (TCC) of varying histologic grade from the urinary bladder. To complement the ultrastructural observations, the immunophenotype of 8 benign BTs was evaluated together with that of 12 TCCs of the bladder using antibodies to thrombomodulin (TM), cytokeratin 20, cytokeratin 7, and carcinoembryonic antigen (CEA), all of which have been shown to react with TCCs of urothelial origin. At the ultrastructural level, there was only limited evidence of a morphologic likeness between the epithelial cells of BTs and those of the benign or neoplastic urothelium. The immunophenotype of the two tumors also differed significantly in that there was no reactivity for TM or cytokeratin 20 in the BTs, while these markers were expressed in the TCCs. Both BTs and TCCs were positive for cytokeratin 7 and may express CEA.

Epithelial mesothelioma with deciduoid features: report of four cases.

Deciduoid mesothelioma is the designation given to an unusual morphologic variant of epithelial mesothelioma that closely simulates exuberant ectopic decidual reaction. Because all four previously reported cases involved the peritoneum and occurred in young women without a history of asbestos exposure, it was suggested that deciduoid mesothelioma was a subtype of epithelial mesothelioma characterized by its unique morphology, that it affects a distinct patient population, and that it is unrelated etiologically to asbestos. The author reports four cases of mesothelioma with deciduoid features, all of which originated in the pleura. Three of the patients were men and one was a woman. Their ages ranged from 46 to 78 years (mean age, 67 yrs). Two of the patients had a history of asbestos exposure. These findings indicate that this morphologic variant of mesothelioma is not limited to a specific patient population nor is it restricted to the peritoneum.

HER-2/neu gene amplification compared with HER-2/neu protein overexpression and interobserver reproducibility in invasive breast carcinoma.

We compared the detection of HER-2/neu gene amplification by fluorescence in situ hybridization (FISH) with detection of HER-2/neu protein overexpression by immunohistochemistry using 2 antibodies on 100 archival invasive breast carcinomas. Protein overexpression for each marker was scored independently by 4 pathologists using standardized criteria, and consensus was compared with results obtained from gene amplification. The concordance rate between FISH and immunohistochemistry was 76% for e2-4001 and 91% for the HercepTest. Of the 37 cases positive by e2-4001, 21 demonstrated no gene amplification; 7 of 24 cases positive by the HercepTest demonstrated no gene amplification. However, 1 of 61 cases negative by e2-4001 showed gene amplification; none of the cases negative by the HercepTest showed amplification. The predictive values of gene amplification based on 0-1+, 2+, and 3+ immunohistochemical staining were best for cases scored as 3+ (75% for e2-4001 and 89% for the HercepTest). Complete agreement among observers for immunohistochemical scoring of e2-4001 and the HercepTest was achieved in 75 and 85 cases, respectively. The pairwise kappa agreement values were substantial for e2-4001 and substantial to almost perfect for the HercepTest. Immunohistochemical staining may be considered a useful screening test. While negative staining almost always correlated with a lack of gene amplification, positive membranous staining, especially 2+, did not predict gene amplification. The low interobserver reproducibility in separating 2+ from 3+ cases necessitates further confirmation by FISH before treatment decisions are made.

Transitional cell carcinomas of the ovary and bladder are immunophenotypically different.

AIMS: Transitional cell carcinoma (TCC) of the ovary is a subtype of ovarian cancer whose main characteristic is its histological resemblance to TCC of the bladder. Thrombomodulin (TM), a surface glycoprotein commonly expressed in normal and neoplastic urothelium, has been proven to be a good marker for TCC of the bladder. To better define the phenotype of TCC of the ovary, we investigated TM, cytokeratin 20 and carcinoembryonic antigen (CEA) expression in 15 TCCs of the ovary and compared their phenotype with that of 20 TCCs of the bladder, and 20 serous and 10 endometrioid carcinomas of the ovary. METHODS AND RESULTS: Immunostaining was performed on formalin-fixed, paraffin-embedded tissue sections using the avidin-biotin-peroxidase complex method. All 20 TCCs of the bladder stained for TM and cytokeratin 20, and 13 stained for CEA. None of the TCCs of the ovary reacted for TM or cytokeratin 20, and only two expressed CEA. All of the serous and endometrioid carcinomas were negative for TM and cytokeratin 20. CEA positivity was observed in two of the serous carcinomas, but in none of the endometrioid carcinomas. CONCLUSION: The immunophenotype of TCC of the ovary is similar to that of other surface carcinomas of the ovary, but differs from that of TCC of the bladder. Since immunohistochemical procedures are often used in the diagnosis and classification of both primary and metastatic tumours, it is important to be aware of these differences in immunophenotype.

Fine-needle aspiration cytology of a case of oncocytic adrenocortical carcinoma.

We report on the results of fine-needle aspiration cytology of a case of oncocytic adrenocortical carcinoma in a 39-yr-old man. The tumor invaded the inferior vena cava and extended up to the right atrium. Aspirate smears were very cellular and showed a monomorphic population of large polyhedral cells with abundant granular cytoplasm, predominantly distributed singly. Mitotic activity was inconspicuous, and there was no necrosis. Immunohistochemically, the tumor cells were positive for vimentin, cytokeratin, and p53, and negative for synaptophysin, chromogranin, inhibin, and S-100. Ultrastructurally, the cytoplasm of the tumor cells was packed with mitochondria. The patient underwent left radical nephrectomy as well as a combined cardiopulmonary bypass, with atriotomy and resection of the tumor from the right atrium and inferior vena cava. Three months of postoperative follow-up were uneventful.

Pigmented carcinoma of the breast: an ultrastructural study.

A pigmented skin lesion on a breast removed for carcinoma resembled melanoma by routine light microscopy, but correlation with immunohistochemistry and electron microscopy established that carcinoma cells within the upper dermis were intermingled with a proliferation of non-neoplastic melanocytic cells. Ultrastructurally, the tumor cells possessed desmosomes and intracytoplasmic lumina and mature melanosomes were present in their cytoplasm. The melanocytic cells were identified as melanocytes or melanophages, and it was concluded that the tumor in the skin was a passively pigmented carcinoma and not a melanoma or metaplastic breast carcinoma.

Primary vulvar and vaginal extraosseous Ewing's sarcoma/peripheral neuroectodermal tumor: diagnostic confirmation with CD99 immunostaining and reverse transcriptase-polymerase chain reaction.

Two cases of extraosseous Ewing's sarcoma/peripheral neuroectodermal tumor arising in unusual, superficial sites are reported. One tumor involved the vaginal wall of a 35-year-old woman, and the other neoplasm arose in the dermis of the vulva in a 28-year-old woman. The tumors showed characteristic microscopic features of Ewing's sarcoma/peripheral neuroectodermal tumor with nodular monotonous proliferations of undifferentiated, small, round, hyperchromatic cells with a low mitotic index. Rare rosette-like formations were apparent only in the vulvar neoplasm. The tumors displayed intense immunoreactivity in a membranous pattern for CD99, the cell surface glycoprotein encoded by the MIC2 gene. Genetically, the tumors expressed the EWS/FLI-1 chimeric transcript, derived from the t(11;22)(q24;q12) chromosomal translocation. Both patients had localized disease treated with wide local excision; one received postoperative chemotherapy, and the other received chemotherapy and radiotherapy. To date, 18 and 19 months after diagnosis, neither patient has had clinical evidence of local recurrence or metastasis. To our knowledge, these are the first reported cases of vaginal and vulvar Ewing's sarcoma/peripheral neuroectodermal tumor, confirmed with molecular genetic analysis, in the English literature.

Value of thyroid transcription factor-1, E-cadherin, BG8, WT1, and CD44S immunostaining in distinguishing epithelial pleural mesothelioma from pulmonary and nonpulmonary adenocarcinoma.

The distinction between malignant pleural mesotheliomas and adenocarcinomas, particularly those originating in the lung, is a difficult diagnostic problem that can be facilitated by the use of immunohistochemical markers. In this study, the immunoreactivity of thyroid transcription factor-1 (TTF-1), E-cadherin, BG8, WT1, and CD44S was investigated in 50 epithelial mesotheliomas, and 40 pulmonary and 95 nonpulmonary adenocarcinomas. After analyzing the results, it was concluded that E-cadherin and BG8 are useful markers for distinguishing between epithelial mesotheliomas and adenocarcinomas of various origins, including the lung. Because TTF-1 expression is found almost exclusively in adenocarcinomas of the lung but is absent in mesotheliomas, immunostaining for this marker is particularly useful for distinguishing between these two malignancies. Although WT1 immunostaining may also be useful, its value, as determined in this study, is lower than that reported by other investigators. CD44S immunostaining does not have any practical value in discriminating between epithelial mesothelioma and lung adenocarcinoma.