Double immunohistochemistry enhances detection of lymphatic and venous invasion in early-stage colorectal cancer.

Lymphatic invasion (LI) and venous invasion (VI) are regarded as important risk factors of nodal disease in early-stage colorectal cancer (CRC) but with variable reporting and poor distinction of these parameters in previous studies. This study examines the application of a double immunohistochemistry (D-IHC) method to help detect and distinguish LI and VI, in comparison with haematoxylin and eosin (H&E) staining, in a clinical series of cases of stage pT1 CRC. The aims were to demonstrate feasibility of this methodology in routine practice and compare rates of LI and VI reporting with and without D-IHC application. D-IHC utilising CAM5.2 with the endothelial marker CD34 and with the specific lymphatic endothelial marker D2-40 was performed on parallel sections from single representative paraffin tissue blocks in 28 cases of stage pT1 CRC from routine clinical practice. D-IHC significantly increased rates of both LI and VI reporting, from 14.3 to 35.7 % and from 14.3 to 28.6 %, respectively. The D-IHC methodology described is technically feasible in routine practice and potentially offers a more sensitive and robust assay for detection and distinction of LI and VI in early CRC pathology reporting. The reproducibility and clinical significance of enhanced LI and VI detection by this method and the relative importance of LI and VI in this clinical setting require further study.

Intestinal-type cervical adenocarcinoma in situ and adenocarcinoma exhibit a partial enteric immunophenotype with consistent expression of CDX2.

Most cases of cervical adenocarcinoma in situ (AIS) and adenocarcinoma are of the usual or endocervical type. However, intestinal types of AIS and adenocarcinoma exist. With an intestinal-type adenocarcinoma in the cervix, the question may arise as to whether one is dealing with a primary cervical neoplasm or direct or secondary spread from an intestinal adenocarcinoma. In organs such as the ovary, urinary bladder, esophagus, and gallbladder, intestinal-type glandular epithelium often expresses enteric markers, but this has hardly been studied in the cervix. The purpose of this study was to investigate whether intestinal-type AIS and adenocarcinoma in the cervix express enteric markers and to ascertain whether these antibodies are of value in the distinction from a metastatic intestinal adenocarcinoma. We compared the immunophenotype of these lesions with that of usual-type AIS and adenocarcinomain the cervix. Cases included were AIS of usual type (n = 6), primary cervical adenocarcinoma of usual type (n = 6), AIS of intestinal type (n = 21), primary cervical adenocarcinoma of intestinal type (n = 3), primary cervical adenocarcinoma with signet ring cells (n = 2), and colorectal adenocarcinoma involving the cervix (n = 5). All cases were stained with cytokeratin (CK) 7, CK20, monoclonal carcinoembryonic antigen (CEA), p16, and CDX2. Staining was categorized as negative, focally positive (<50% cells), or diffusely positive (50% or more cells). Usual-type AIS was always diffusely CK7 positive, typically diffusely CEA and p16 positive, and always CK20 negative. CDX2 was positive in 1 case. All usual cervical adenocarcinomas were diffusely CK7 and p16 positive, and all were immunoreactive with CEA. Five and 2 cases were CK20 and CDX2 positive, respectively. Intestinal-type AIS was diffusely CK7 positive (all cases) and typically CK20 negative and diffusely CEA and p16 positive. All but 1 case exhibited diffuse nuclear positivity with CDX2. In addition, usual-type AIS adjacent to intestinal type was CDX2 positive in 13 of 21 cases. The 3 cases of primary cervical intestinal-type adenocarcinoma were diffusely CK7 positive, focally or diffusely positive with CK20 and CDX2, and focally positive with CEA. One case was diffusely p16 positive, 1 focal and 1 negative. The foci of signet ring cells in the 2 primary cervical adenocarcinomas were diffusely CK7 and p16 positive and negative with CK20 and CDX2. Colorectal adenocarcinomas involving the cervix were typically diffusely positive with CK20, CEA, and CDX2; negative with CK7; and negative or focally positive with p16. Intestinal types of cervical AIS and adenocarcinoma exhibit a partial enteric immunophenotype, usually with diffuse expression of CDX2 and, in some cases, staining with CK20. They maintain their CK7 immunoreactivity and are usually p16 positive. Although there is immunophenotypic overlap, focal staining with CK20 together with diffuse CK7 and sometimes p16 positivity helps to distinguish intestinal types of cervical adenocarcinoma from involvement by a colorectal adenocarcinoma; CEA and CDX2 are of no value in this regard. CDX2 positivity in usual-type AIS adjacent to intestinal type and in occasional cases of pure usual-type AIS may be a reflection of early intestinal differentiation before this is morphologically apparent. Using a set of cases of AIS diagnosed in a single institution over a 7-year period (77 usual type; 13 intestinal type), intestinal type was more likely to be associated with early invasive adenocarcinoma than usual type (31% vs 17%), suggesting that intestinal differentiation may be a risk factor for invasion in premalignant cervical glandular lesions.

Uterine leiomyosarcomas are characterized by high p16, p53 and MIB1 expression in comparison with usual leiomyomas, leiomyoma variants and smooth muscle tumours of uncertain malignant potential.

AIMS: It has been suggested that p16 is overexpressed in uterine leiomyosarcomas in comparison with leiomyomas. In this study, p16 immunohistochemical expression was assessed in a variety of uterine smooth muscle tumours, including usual leiomyomas, leiomyoma variants, smooth muscle tumours of uncertain malignant potential (STUMPs) and leiomyosarcomas. The aim was to ascertain whether there are differences in p16 expression between these groups and whether p16 is of potential value in the assessment of problematic uterine smooth muscle neoplasms. p16 expression was also compared with that of p53 and MIB1. METHODS AND RESULTS: Cases of usual leiomyoma (n = 10), leiomyoma variants (n = 27), STUMP (n = 4) and leiomyosarcoma (n = 22) were subject to p16, p53 and MIB1 immunohistochemistry. For p16, cases were evaluated with respect to both staining distribution and intensity. There was a statistically significant difference in p16 distribution (P < 0.001) and intensity (P = 0.001) between leiomyosarcomas and the other groups. There was no difference in p16 expression between usual leiomyomas, leiomyoma variants and STUMPs. There were also statistically significant differences in p53 (P = 0.014) and MIB1 (P < 0.001) immunoreactivity between leiomyosarcomas and the other groups. CONCLUSIONS: p16 is overexpressed in uterine leiomyosarcomas compared with leiomyomas, benign leiomyoma variants and STUMPs, suggesting that p16 may be implicated in the pathogenesis of malignant uterine smooth muscle neoplasms. p16, in combination with p53 and MIB1, may be of value as an adjunct to morphological examination in the assessment of problematic uterine smooth muscle tumours, although further large-scale studies with follow-up are necessary to confirm this.

High-grade ovarian serous carcinoma exhibits significantly higher p16 expression than low-grade serous carcinoma and serous borderline tumour.

AIMS: A dualistic pathway of ovarian serous carcinogenesis is now well established whereby high-grade serous carcinoma and low-grade serous carcinoma represent two distinct tumour types with a different underlying pathogenesis. The aim of this study was to compare expression of p16 INK4A (p16) in these two tumour types. We also included cases of serous borderline tumour, since these are considered to represent a precursor lesion of low-grade serous carcinoma. METHODS AND RESULTS: Cases of serous borderline tumour (n = 18), low-grade ovarian serous carcinoma (n = 22) and high-grade ovarian serous carcinoma (n = 24) were stained with a monoclonal antibody against p16. Cases were scored both with respect to intensity of immunoreactivity (weak, 1+; moderate, 2+; or strong, 3+) and distribution (0, negative or occasional positive cells; 1+, < 10% cells positive; 2+, 10-25% cells positive; 3+, 26-50% cells positive; 4+, 51-75% cells positive; or 5+, 76-100% cells positive). An immunohistochemical composite score was also calculated (0-15) by multiplying the intensity and distribution scores. There was a statistically significant difference in p16 immunoreactivity with respect to intensity, distribution and composite score between high-grade serous carcinoma and each of the other two groups, with the high-grade neoplasms exhibiting stronger and more diffuse positivity. Most high-grade serous carcinomas exhibited positivity of close to 100% of tumour cells. There was no significant difference in p16 expression between the borderline tumours and low-grade serous carcinomas. CONCLUSIONS: The increased expression of p16 in high-grade serous carcinoma compared with low-grade serous carcinoma and serous borderline tumour is in keeping with a different underlying pathogenesis. p16 may be implicated in the development of high-grade serous neoplasia within the ovary and elsewhere within the female genital tract.

An immunohistochemical analysis of ovarian small cell carcinoma of hypercalcemic type.

Ovarian small cell carcinoma of hypercalcemic type (OSCCHT) is a rare neoplasm with an aggressive behavior, broad differential diagnosis, and unknown histogenesis. To add to knowledge concerning the possible aid of immunohistochemistry in resolving problems in differential diagnosis and to further explore whether that modality points to any specific histogenesis, we undertook an immunohistochemical study of this neoplasm. Fifteen OSCCHTs (including four of the ''large cell" variant) were stained with a range of antibodies, some of which have not been investigated previously in this neoplasm. Cases were stained with AE1/3, EMA, BerEP4, CK5/6, calretinin, WT1, chromogranin, CD56, synaptophysin, CD99, NB84, desmin, S100, CD10, alpha inhibin, TTFI, and p53. Staining was classified as 0 (negative), 1+ (<5% cells positive), 2+ (5% to 25% cells positive), 3+ (26% to 50% cells positive), or 4+ (>50% cells positive). All cases were positive with p53 (two 1+, five 3+, eight 4+), 14 of 15 cases were positive with WT1 (one 1+, thirteen 4+), 14 of 15 with CD10 (three 1+, four 2+, two 3+, five 4+), 13 of 15 with EMA (three 1+, three 2+, two 3+, five 4+), 11 of 15 with calretinin (nine 1+, one 3+, one 4+), 9 of 15 with AE1/3 (eight 1+, one 2+), 4 of 15 with CD56 (one 1+, two 2+, one 4+), 3 of 15 with BerEP4 (two 2+, one 4+), 2 of 15 with synaptophysin (two 1+), and 1 of 15 with S100 (4+). All cases were negative with CK5/6, chromogranin, CD99, NB84, desmin, alpha inhibin, and TTF1. The only noticeable difference in the immunophenotype between typical OSCCHT and the large cell variant was that there was 4 +EMA positivity in three of four cases of large cell variant compared with two of 11 cases of typical OSCCHT. OSCCHT is characteristically positive with AE1/3, EMA, CD10, calretinin, WT1, and p53. Combined EMA and WT1 positivity, the latter usually intense and diffuse, may be of diagnostic value, inasmuch as only a few of the neoplasms in the differential diagnosis are positive with both antibodies. Negative staining with CD99, desmin, NB84, alpha-inhibin, and TTF1 may aid in the cases in which primitive neuroectodermal tumor, rhabdomyosarcoma, intraabdominal desmoplastic small round cell tumor, neuroblastoma, a sex cord-stromal tumor, and metastatic pulmonary small cell carcinoma are in the differential. Calretinin positivity precludes its use in the differential with granulosa cell tumors. The results of this investigation do not settle the issue of histogenesis, which remains enigmatic. The typical age distribution, follicle formation, and calretinin positivity are consistent with a sex cord origin. On the other hand, WT1 and EMA positivity and negative staining with alpha-inhibin would be unusual in a sex cord-stromal neoplasm and can be used as an argument for a surface epithelial origin. Germ cell and neuroendocrine origins seem highly unlikely.

Cytomegalovirus infection of the cervix: morphological observations in five cases of a possibly under-recognised condition.

AIMS: Histologically diagnosed cytomegalovirus (CMV) infection of the cervix is rare and the associated morphological features are not well described. This study describes histopathological findings in five biopsies from four patients with CMV cervicitis. METHODS: CMV inclusions were identified in five cervical biopsies from four patients in a single institution over eight months. The clinical notes were reviewed, the morphological features documented, and immunohistochemical staining for CMV performed. CMV immunohistochemical staining was also performed on 30 consecutive cervical biopsies in which inclusions were not seen histologically. RESULTS: None of the patients was immunocompromised but one was postnatal. Numbers of CMV inclusions ranged from occasional to abundant and they were located mainly in endocervical glandular epithelial cells but also in endothelial and mesenchymal cells. Inclusions were not seen in squamous cells. Inclusions were eosinophilic and were intracytoplasmic rather than intranuclear. They were positive immunohistochemically for CMV. Associated morphological features included fibrin thrombi within small blood vessels (three cases), dense active inflammatory infiltrates (five cases), lymphoid follicles (two cases), vacuolation of glandular epithelial cells (two cases), and reactive changes in glandular epithelial cells (two cases). CMV inclusions were not identified in the 30 additional cases that underwent immunohistochemical staining. CONCLUSIONS: CMV infection of the cervix may be more common than is thought. Patients are usually immunocompetent and require no treatment. Morphological features such as a dense inflammatory cell infiltrate with lymphoid follicles, and especially fibrin thrombi within small vessels, should alert the pathologist to look closely for the pathognomonic CMV inclusion bodies.

Immunohistochemical expression of CD10 and t(14;18) chromosomal translocation may be indicators of follicle centre cell origin in nodal diffuse large B-cell lymphoma.

AIMS: Although diffuse large B-cell lymphoma is categorized as a distinct entity in the REAL classification of lymphomas, it represents a heterogeneous group of neoplasms. A subgroup is probably of follicle centre cell origin and may evolve from a pre-existing follicular lymphoma. The t(14;18) chromosomal translocation can be demonstrated in the majority of follicular lymphomas and the aim of this study was to investigate the prevalence of t(14;18) translocation in a series of de novo nodal diffuse large B-cell lymphomas. We correlated this with the immunohistochemical expression of CD10, bcl2 and bcl6, markers which are usually expressed by the neoplastic cells in follicular lymphomas. We also correlated these parameters with the presence or absence of p53 protein expression by the neoplastic cells. METHODS AND RESULTS: Nodal diffuse large B-cell lymphomas (n=34) were stained immunohistochemically with monoclonal antibodies to CD10, bcl2, bcl6 and p53 (D07). Polymerase chain reaction (PCR) for the t(14;18) translocation was also performed. Fourteen, 24 and 29 (41%, 71%, 85%) cases exhibited positivity for CD10, bcl2 and bcl6, respectively. In 12 cases there was positivity with D07 (35%). By PCR, the t(14;18) translocation was identified in five cases (15%), four of which were positive for CD10 and bcl2 and all of which were positive for bcl6. One of five cases positive for the chromosomal translocation exhibited positivity with D07. CONCLUSIONS: In this study the t(14;18) translocation was identified in 15% of diffuse large B-cell lymphomas, all but one of which exhibited positivity for CD10, bcl2 and bcl6. These may represent cases of follicle centre cell origin which may or may not have evolved from a pre-existing follicular lymphoma. It is possible that positivity for CD10 especially may identify cases which are of follicle centre cell origin and that the absence of t(14;18) translocation in some of these cases may reflect the fact that the translocation cannot normally be demonstrated in all follicular lymphomas. Whether the presence or absence of the translocation and the immunophenotype are prognostically important should be investigated further.

Monoclonal antibodies Ki-67 and MIB1 in the distinction of tuboendometrial metaplasia from endocervical adenocarcinoma and adenocarcinoma in situ in formalin-fixed material.

This study was undertaken to determine whether immunostaining with the monoclonal antibodies Ki-67 and MIB1 is of use in the distinction of tuboendometrial metaplasia from endocervical adenocarcinoma and adenocarcinoma in situ (AIS) on formalin-fixed, paraffin-embedded tissue. Tissue sections from 100 cases (52 normal endocervix, 27 endocervical tuboendometrial metaplasia, eight endocervical AIS, 13 endocervical adenocarcinoma) were stained with Ki-67 and MIB1 after microwave pretreatment in citrate buffer. Ki-67 and MIB1 labelling indices (LIs) were calculated in each case by determining the percentage of positive-staining nuclei. Five hundred nuclei were counted in each case. Significant differences in Ki-67 and MIB1 LIs existed between the adenocarcinoma group and the tuboendometrial metaplasia group and between the AIS group and the tuboendometrial metaplasia group. No significant differences existed between the adenocarcinoma and AIS groups. Over all groups, the Ki-67 LI was consistently lower than the MIB1 LI. The results indicate that immunohistochemical staining with Ki-67 and MIB1 may be of use in the often difficult histological distinction of tuboendometrial metaplasia from malignant endocervical glandular lesions.

Stability of cefazolin sodium and metronidazole at 8 degrees C for use as an i.v. admixture.

The stability of cefazolin 1 g in metronidazole 500 mg/100 mL at 8 degrees C was studied for use as an IV admixture. The commercially available injection of cefazolin sodium 1 g vial was diluted to 5 mL with 0.9% sodium chloride injection and added to metronidazole 500 mg/100 mL. Following dilution of 2 mL to 100 mL with water, 1-mL aliquots were transferred to glass vials, refrigerated at 8 degrees, and assayed for cefazolin and metronidazole concentration at 0, 1, 2, 4, 8, 12, 24, 36, 48, and 72 hours after preparation. The concentration of cefazolin and metronidazole was determined by a stability-indicating high-performance liquid chromatographic method. The range of concentration was determined to be within 5% of the 0-hour mean concentration. Over the 72-hour period, the mean concentration of cefazolin at all assay times was within 98.4 to 101.0% of the initial concentration. The mean concentration of metronidazole at each assay time was 96.9 to 104.9% of the initial concentration. Cefazolin sodium 10 mg/mL and metronidazole 5 mg/mL, prepared by adding reconstituted cefazolin to a glass bottle of metronidazole ready-to-use solution, were stable for 72 hours when stored at 8 degrees C.

Stability of cefotaxime sodium and metronidazole in an i.v. admixture at 8 degrees C.

The stability of cefotaxime and metronidazole in i.v. admixture at 8 degrees C was studied. The commercially available injectable formulation of cefotaxime sodium 1 g was diluted to 5 mL with 0.9% sodium chloride injection and added to metronidazole injection 500 mg/100 mL. A 2-mL sample was removed and diluted to 100 mL with water. Thirty 1-mL portions were transferred to glass vials and refrigerated at 8 degrees C. At 0, 1, 2, 4, 8, 12, 24, 36, 48, and 72 hours after the admixture was prepared, the vials were removed, placed in a refrigerated autosampler, and assayed for cefotaxime and metronidazole concentrations by stability-indicating high-performance liquid chromatography. Over the 72-hour study period, the concentration of cefotaxime remaining at all assay times was 95.91-101.13% of the initial concentration. The concentration of metronidazole remaining at each assay time was 93.08-102.19% of the initial concentration. Cefotaxime sodium 10 mg/mL and metronidazole 5 mg/mL were stable for 72 hours at 8 degrees C in an i.v. admixture prepared from commercially available injectable formulations.

Stability of gentamicin sulfate and tobramycin sulfate in extemporaneously prepared ophthalmic solutions at 8 degrees C.

The stability of gentamicin sulfate and tobramycin sulfate in fortified ophthalmic solutions stored under refrigeration was studied. Fortified gentamicin ophthalmic solution and fortified tobramycin ophthalmic solution were prepared to a final theoretical concentration of 13.6 mg/mL by using commercially available ophthalmic and injectable solutions. Volumes of each solution were packaged in plastic bottles and refrigerated at 4-8 degrees C. Samples of each solution were analyzed by fluorescence polarization immunoassay on days 0 (before refrigeration), 1, 2, 3, 4, 7, 14, 28, 63, and 91. To validate the method, identical solutions were prepared, stored under refrigeration at 4-8 degrees C, and analyzed by a stability-indicating high-performance liquid chromatographic assay on days 0 (before refrigeration), 9, 28, 56, and 91. Fluorescence polarization immunoassay showed the mean concentrations of gentamicin and tobramycin on day 91 to be 104.4% and 97.4%, respectively, of the time 0 concentrations; the difference was not significant in either case. HPLC validated these results; the mean concentration of gentamicin and tobramycin on day 91 was 103.3% and 101.2%, respectively, of the mean day 0 concentrations. Gentamicin and tobramycin in ophthalmic solutions prepared by mixing ophthalmic and injectable products and stored in plastic bottles at 4-8 degrees C were stable for three months.