Inducible microsomal prostaglandin E synthase is overexpressed in colorectal adenomas and cancer.

Recently, an inducible microsomal human prostaglandin E synthase (mPGES) was identified. This enzyme converts the cyclooxygenase (COX) product prostaglandin (PG) H(2) to PGE(2), an eicosanoid that has been linked to carcinogenesis. Increased amounts of PGE(2) have been observed in many tumor types including colorectal adenomas and cancers. To further elucidate the mechanism responsible for increased levels of PGE(2) in colorectal tumors, we determined the amounts of mPGES and COX-2 in 18 paired samples (tumor and adjacent normal) of colorectal cancer. With immunoblot analysis, mPGES was overexpressed in 83% of colorectal cancers. COX-2 was also commonly up-regulated in these tumors; marked differences in the extent of up-regulation of mPGES and COX-2 were observed in individual tumors. Immunohistochemistry revealed increased mPGES immunoreactivity in neoplastic cells in both colorectal adenomas and cancers compared with adjacent normal colonic epithelium. Cell culture was used to investigate the regulation of mPGES and COX-2. Chenodeoxycholate markedly induced COX-2 but not mPGES in colorectal cancer cells. Tumor necrosis factor-alpha induced both mPGES and COX-2, but the time course and magnitude of induction differed. As reported previously for COX-2, overexpressing Ras caused a several-fold increase in mPGES promoter activity. Taken together, our results suggest that overexpression of mPGES in addition to COX-2 contributes to increased amounts of PGE(2) in colorectal adenomas and cancer. The mechanisms controlling the expression of these two enzymes are not identical.

Cytokeratin 19 immunoreactivity in the diagnosis of papillary thyroid carcinoma: a note of caution.

To evaluate the expression of cytokeratin (CK) 19, we stained sections obtained from formalin-fixed, paraffin tissue blocks of 35 thyroid tumors (follicular adenoma [FA], 20; papillary thyroid carcinoma [PTC], 10 follicular variant [FV] and 5 usual type) and scored the extent of staining as follows: 1+ (<5% positively stained cells), 2+ (5%-25% positively stained cells), 3+ (25%-75% positively stained cells), and 4+ (>75% positively stained cells). All 15 PTCs (including 10 FV-PTCs) were CK19 positive: 14 were 4+ and 1 (FV-PTC) was 2+. All 20 FAs also were CK19 positive: 15 were 1+, 1 was 2+, 4 were 3+, and none was 4+. In the FAs that were scored 1+, reactivity usually was confined to follicular cells lining cystically dilated atrophic follicles that lacked the typical nuclear features of PTC. The remaining FAs showed more diffuse reactivity, which was, however, less intense than that observed in the PTCs. Thus, immunoreactivity for CK19 is not specific for PTC, although we acknowledge that the extent and intensity of staining are considerably greater in this tumor than in FA. There were no significant differences in staining for CK19 between nonneoplastic follicles adjacent to PTCs and those adjacent to FAs.

Synchronous water-clear cell double parathyroid adenomas a hitherto uncharacterized entity?

Water-clear cell hyperplasia is a rare but well-documented cause of primary hyperparathyroidism. Parathyroid adenomas of the water-clear cell type are exceptionally rare, and only 2 cases have been reported. We describe a patient with synchronous water-clear cell double parathyroid adenomas, an entity that has not previously been reported. In our case, the enlarged superior parathyroid glands were completely replaced by water-clear cells, with only a minute rim of extracapsular, histologically unremarkable parathyroid tissue. The inferior parathyroid glands were grossly unremarkable, and incisional biopsy specimens were histologically normal (no foci of water-clear cells were identified). The findings in this case are most consistent with the diagnosis of double adenomas of the water-clear cell type. We acknowledge that despite molecular proof of monoclonality of the 2 lesions, it is not possible to entirely exclude the possibility that this unusual case could be due to asymmetric hyperplasia.

The neuroendocrine system and its tumors: an overview.

Neuroendocrine tumors comprise a family of neoplasms with a wide range of morphologic, functional, and behavioral characteristics. Their diagnosis depends on the recognition of characteristic morphologic features and on the presence of markers indicative of neuroendocrine differentiation. Neuroendocrine tumors can be grouped into epithelial and neural subtypes on the basis of the presence of cytokeratins or neurofilaments, respectively. The nomenclature of these tumors, particularly those of the epithelial type, remains controversial. For some tumor types, such as those of the anterior pituitary, thyroid, and parathyroid glands, the standard terminology is preferable to the terms neuroendocrine tumor or neuroendocrine carcinoma. The use of the term carcinoid, however, has become increasingly more inappropriate to describe the full range of neuroendocrine neoplasms of low to intermediate malignant potential. It is critical to convey in diagnostic teminology both the tumor type and its malignant potential. Diagnostic terms using neuroendocrine or endocrine together with information on grading and hormonal activity provide an optimal approach for the classification of these tumors. Additional studies, including gene expression profiling, will be critical for further advancing our understanding of the pathobiology and interrelationships of these neoplasms.

Small cell carcinoma of the breast: a clinicopathologic and immunohistochemical study of nine patients.

Small cell carcinoma of the breast is an uncommon neoplasm that has been reported rarely in the literature. The aim of this study was to characterize better the pathologic and immunohistochemical features of this neoplasm. Nine examples of mammary small cell carcinoma were retrieved from the authors' consultation files and reviewed. The patients ranged in age from 43 to 70 years. Two patients had a previous history of cutaneous malignant melanoma and one had prior lobular carcinoma in situ and atypical duct hyperplasia in the same breast as the small cell carcinoma. Eight patients presented with a mass in the breast; one patient had an axillary tumor. Tumor size ranged from 1.3 to 5.0 cm (mean, 2.6 cm). Histologically, the nine tumors had characteristics of small cell carcinoma with high mitotic activity and necrosis. A dimorphic histologic appearance was observed in four tumors. In one instance, this consisted of small cell carcinoma merging with invasive lobular carcinoma. In three cases, small cell carcinoma was present together with invasive, poorly differentiated duct carcinoma; invasive carcinoma with "lobular and gland-forming elements"; and focal squamous differentiation, respectively. Lymphatic tumor emboli were identified in four instances. An in situ component was seen in seven tumors; five were of the small cell type in ducts and two were of the ductal type with high nuclear grade. Immunohistochemical analysis showed consistent staining for cytokeratin markers but variable staining with neuroendocrine markers. Sixty-six percent of the tumors (six of nine) were reactive for chromogranin, synaptophysin, or peptide hormones, including four positive for chromogranin and synaptophysin, one positive for synaptophysin and calcitonin, and one positive for calcitonin alone. One tumor that was reactive for chromogranin and synaptophysin also contained calcitonin immunoreactive cells, whereas gastrin-releasing peptide was present in two other tumors that were also positive for chromogranin. Leu 7 was positive in three cases that were reactive for either chromogranin or synaptophysin. Five tumors were estrogen and progesterone receptor-positive. All tumors were positive for bcl-2 and negative for HER2/neu. Patients were treated by mastectomy (n = 3) or lumpectomy (n = 6). Eight underwent an axillary dissection that revealed metastatic carcinoma in four patients. Seven patients received adjuvant chemotherapy and four patients received radiation. Two patients also received tamoxifen treatment. Metastases developed in two patients (22%) with a follow-up period of 11 and 32 months. All patients were alive at last follow up 3 to 35 months after treatment. When compared with published reports of mammary small cell carcinoma, our results show that the prognosis in these patients may not be as poor as previously suggested.

Diagnostic utility of the monoclonal antibody A103 in fine-needle aspiration biopsies of the adrenal.

Fine-needle aspiration (FNA) of the adrenal is a useful modality for the evaluation of primary and metastatic neoplasms. Until now, however, few reliable markers existed for the positive identification of adrenal cortical cells. Originally studied as a melanoma marker, Melan-A, as detected by the murine monoclonal antibody, A103, has gained recent attention as a marker for steroid-producing cells. Formalin-fixed, paraffin-embedded cell blocks from 24 adrenal FNA specimens were stained for cytokeratins (AE1/AE3) and Melan-A (A103). Seven of 8 cases containing normal, hyperplastic, and neoplastic adrenal cortical cells were positive for A103. Among 16 cases of metastatic carcinoma, tumor cells in 14 samples were positive for cytokeratins but negative for A103. The A103 monoclonal antibody is a sensitive marker for the identification of normal, hyperplastic, and neoplastic adrenal cortical cells in cell blocks of adrenal FNA specimens. With the exception of melanoma, A103 reactivity is restricted to adrenal cortical and other steroid-producing cells. A103 should be used routinely for the evaluation of FNA specimens of adrenal mass lesions.

The hereditary forms of pancreatic neuroendocrine tumors.

Pancreatic endocrine tumors occur sporadically or in the setting of multiple endocrine neoplasia type I (MEN-1) or von-Hippel-Lindau disease. In the latter circumstances, the tumors are often multiple. This commentary addresses the differences in clinical, pathologic, and molecular features of MEN-1 and von Hippel-Lindau disease associated pancreatic endocrine tumors.

Sustained biochemical and histologic remission of primary biliary cirrhosis in response to medical treatment.

BACKGROUND: Treatment of primary biliary cirrhosis with ursodiol or colchicine may stabilize the disease or slow its rate of progression, but no reports of spontaneous or treatment-related remission have been published. OBJECTIVE: To determine whether primary biliary cirrhosis fully responds to low-dose oral methotrexate therapy. DESIGN: Prospective case study with at least 6 years of observation. SETTING: Academic medical center. PATIENTS: 5 of 19 patients with biopsy-proven precirrhotic primary biliary cirrhosis who had been ill for at least 1 year. Three of the 5 had not responded to colchicine or had responded only partially. INTERVENTION: Oral methotrexate, 15 mg/wk in divided doses. MEASUREMENTS: Symptoms, biochemical tests of liver function, and percutaneous liver biopsies. The latter were done at baseline, 1 to 2 years after initiation of methotrexate therapy, and then every 2 to 3 years during methotrexate therapy. RESULTS: All 5 patients completely responded to medical treatment. Results of biochemical tests of liver function, became normal, symptoms remitted, and serial liver biopsy specimens showed progressive histologic improvement. Biopsy specimens obtained after 5 to 12 years of treatment showed few signs of primary biliary cirrhosis and, in 3 patients, were close to normal. Five of the other 14 patients have responded biochemically and have shown histologic improvement; the other 9 have not responded to methotrexate therapy, have discontinued therapy, or have been lost to follow-up. CONCLUSION: In some patients, primary biliary cirrhosis may remit in response to methotrexate alone or in combination with colchicine or ursodiol.

Lymph node negative invasive breast carcinoma 1 centimeter or less in size (T1a,bNOMO): clinicopathologic features and outcome.

BACKGROUND: Patients with lymph node negative invasive breast carcinomas < or = 1 cm in size have a low recurrence rate and may be spared adjuvant therapy. Reliable prognostic features will help physicians design appropriate treatment for these patients. METHODS: The clinicopathologic features, prognostic marker profiles, and clinical outcomes of 88 T1a,bN0M0 carcinomas in 87 patients who presented between 1975 and 1990 were studied. The size of each tumor was determined by direct measurement of histologic sections. The median follow-up was 7.8 years (range, 4-15 years). The characteristics of tumors diagnosed between 1975 and 1983 and between 1984 and 1990 were also compared. RESULTS: Before 1984, the majority of patients presented with palpable mass lesions, whereas from 1984 on, more patients presented with mammographic abnormalities. However, no significant differences in the pathologic features of tumors were observed between the two periods. There were only 3 locoregional recurrences (3%) and 4 distant recurrences (5%). Palpable tumors had worse prognoses than mammographically detected lesions (P = 0.02). Histologic grade, lymphatic invasion, hormone receptors, Ki-67 antigen, and bcl-2 expression were significant univariate prognostic indicators. The small number of patients in the series precluded multivariate analysis. None of the 43 patients (49%) with tumors < or = 0.5 cm, or of histologic and nuclear Grade 1, or of favorable histologic types developed recurrences; and their outcomes were significantly better than those of other patients (P = 0.013). Tumors originally classified as T1b, but which exceeded 1 cm on review and were excluded from the study, had a significantly higher distant recurrence rate (23%) than bona fide T1a,b carcinomas (P = 0.03). CONCLUSIONS: T1a,bN0M0 carcinomas have a low recurrence rate, especially those tumors < or = 0.5 cm, or of low histologic or nuclear grade, or of favorable histologic type. The high recurrence among patients with tumors initially understaged as T1a,b carcinoma underscores the importance of accurately determining tumor size.

Proliferation markers in neuroendocrine tumors: useful or useless? A critical reappraisal.

Over the past several years, proliferation markers such as MIB-1 have become important adjuncts in the analysis of neuroendocrine (NE) tumors. Published data have suggested that MIB-1 analysis is useful for the distinction of benign and malignant NE tumors and that it can be used to predict aggressiveness of malignant NE tumors. Analysis of MIB-1, however, is subject to many variables including factors inherent in the basic biology of the tumors, case selection criteria and methods of evaluation of stained sections. While studies of MIB-1 have provided the first step in assessing the malignancy of NE tumors, multiparametric approaches examining the full range of cyclins, cyclin inhibitors, factors controlling apoptosis, oncogenes and tumor suppressor genes will be essential to resolve these issues. For the present. MIB-1, by itself, cannot be used to judge the malignancy of individual NE tumors, but this marker may have utility in identifying subsets of tumors that may have an aggressive course.

Multinucleate giant cells in papillary thyroid carcinoma. A morphologic and immunohistochemical study.

Multinucleate giant cells (MGCs) occur in a variety of inflammatory, hyperplastic, and neoplastic thyroid disorders. They also have been recognized as a feature of papillary thyroid carcinoma (PTC), particularly in fine-needle aspiration biopsies (FNAB). However, the origin of the MGCs and their comparative frequencies in histologic and cytologic preparations have not been established. Therefore, histologic sections from 76 cases of PTC were examined and immunohistochemical analyses for epithelial and histiocytic markers were performed. Giant cells were identified in histologic sections of 35 cases (46%) of PTC. In cytologic preparations, MGCs were identified in 12 of 22 cases (55%). MGCs were present within follicles or adjacent to papillae, and were often associated with resorption of colloid. Immunohistochemical results indicated that MGCs were of histiocytic rather than epithelial origin. Multinucleate giant cells in PTC most likely represent a response to leakage of colloid into the interstitium. Although MGCs have been described most commonly in inflammatory conditions of the thyroid, the results of this study suggest that their presence should prompt a careful appraisal of associated PTC.

Effect of microwave oven heating times on androgen receptor antigen retrieval from paraffin-embedded prostatic adenocarcinoma.

The aim of this study was to investigate the effect of microwave oven heating for antigen retrieval on the immunoreactivity of human prostate carcinoma androgen receptor (AR) in tissue sections. Formalin-fixed, paraffin-embedded tissue sections were microwaved at 5-min intervals for a total of 15, 20, 25, 30, 35 minutes at maximum power (700W). The monoclonal antibody F39.4.1 directed against human AR was used at a 1:10 dilution. Without microwave oven heating, prostatic tissue did not exhibit any AR immunoreactivity. Moderate positivity appeared after three 5-minute cycles of microwave heating. The intensity of immunoreactivity improved progressively with heating times of 20 and 25 min up to an optimum time of 30 minutes, when nuclear staining was most intense with the absence of background staining and without loss of morphological details. While antigen retrieval is effective in restoring antigenicity in a variety of setting, the length of time prostate tissue is exposed to microwave radiation is critical in order to obtain optimal AR immunostaining. AR immunostaining reliably permitted evaluation of the distribution and intensity of positively stained nuclei and the distinction of the various cell types in archival material.