Immunostaining Patterns of Posttransplant Liver Biopsies Using 2 Anti-C4d Antibodies.

Histopathologic diagnosis of antibody-mediated rejection in posttransplant liver biopsies is challenging. The recently proposed diagnostic criteria by the Banff Working Group on Liver Allograft Pathology require positive C4d immunohistochemical staining to establish the diagnosis. However, the reported C4d staining patterns vary widely in different studies. One potential explanation may be due to different antibody preparations used by different investigators. In this study, posttransplant liver biopsies from 69 patients histopathologically diagnosed with acute cellular rejection, chronic rejection, or recurrent hepatitis C were immunohistochemically stained using 2 polyclonal anti-C4d antibodies. On the basis of the distribution of C4d immunoreactivity, 5 different staining patterns were observed: portal vein and capillary, hepatic artery, portal stroma, central vein, and sinusoids. The frequency, extent, and intensity of positive C4d staining with the 2 antibody preparations differed significantly for portal veins/capillaries and central veins, but not for hepatic arteries and portal stroma. Positive sinusoidal staining was seen in only 1 case. There were no significant differences in the frequency, extent, and intensity of positive C4d staining among the acute cellular rejection, chronic rejection, and recurrent hepatitis C groups with the 2 anti-C4d antibodies. These data show that different anti-C4d antibodies can show different staining patterns, which may lead to different interpretation. Caution is thus needed when selecting C4d antibodies for clinical use to aid in the diagnosis of antibody-mediated rejection.

Practical Immunohistochemistry in Neoplastic Pathology of the Gastrointestinal Tract, Liver, Biliary Tract, and Pancreas.

CONTEXT: - Immunomarkers with diagnostic, therapeutic, or prognostic values have been increasingly used to maximize the benefits of clinical management of patients with neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas. OBJECTIVES: - To review the characteristics of immunomarkers that are commonly used in surgical pathology practice for neoplasms of the gastrointestinal tract, liver, biliary tract, and pancreas, and to summarize the clinical usefulness of immunomarkers that have been discovered in recent years in these fields. DATA SOURCES: - Data sources include literature review, authors' research data, and personal practice experience. CONCLUSIONS: - Immunohistochemistry is an indispensable tool for the accurate diagnosis of neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas. Useful immunomarkers are available to help distinguish malignant neoplasms from benign conditions, determine organ origins, and subclassify neoplasms that are morphologically and biologically heterogeneous. Specific immunomarkers are also available to help guide patient treatment and assess disease aggressiveness, which are keys to the success of personalized medicine. Pathologists will continue to play a critical role in the discovery, validation, and application of new biomarkers, which will ultimately improve patient care.

Inflamed conjunctival nevi: histopathological criteria.

Inflamed conjunctival nevi (ICN) may suggest malignancy because of their rapid growth and atypical histology. The objective of this study was to characterize the diagnostic features of ICN. A retrospective, nonrandomized study of 13 patients with ICN was conducted. A scoring method was developed based on histology and immunopathological parameters. The presence of epithelial solid or cystic inclusions and the preservation of goblet cells are consistent with a benign melanocytic lesion. Periodic acid-Schiff stain and immunohistochemistry to identify the epithelial component prove helpful in the differential diagnosis for melanoma. Polyclonal lymphoid infiltrate and benign cytological features of ICN exclude a diagnosis of lymphoma. Despite the presence of immunoglobulin 4-positive plasma cells in the lesions, ICN does not meet the diagnostic criteria for immunoglobulin 4-related disease. Most patients with ICN are young. The treatment for ICN is complete excision, and the prognosis is excellent.

Calcified amorphous tumor of the heart: case report and review of the literature.

Calcified amorphous tumor of the heart (cardiac CAT) is a rare non-neoplastic cardiac mass that mimics malignancy on imaging and can cause symptoms due to flow obstruction or embolization of calcific fragments. We report a 57-year-old female with multiple medical problems affected by cardiac CAT. The echocardiogram showed a 2 x 1.7 cm right atrial mass. Under the clinical diagnosis of cardiac myxoma, a mass resection was performed. Microscopic examination of the resected mass showed nodular calcified amorphous debris with admixed degenerated fibrin and focal chronic inflammation. At the 1-year follow-up, the patient was free of disease. We performed a literature review of 16 previously reported cases. Histologically, a cardiac CAT consists of calcification and eosinophilic amorphous material in the background of dense collagenous fibrous tissue. A review of these cases shows a wide range of age at diagnosis and slight female predominance. The patients are either asymptomatic at presentation or complain of shortness of breath. The tumors have been found in all chambers of the heart, most commonly in the left ventricle. The sizes of the tumors range from 0.17 to 4 cm, with 62.5% of the tumors being mobile. Among the nine cases with documented follow-up study, all but one was free of disease and only one case of relapse was recorded. In conclusion, cardiac CATs are frequently asymptomatic at presentation, size is equal to or less than 4 cm, they can be located in all four chambers and are usually mobile, and they may relapse when not completely excised.

De novo large cell neuroendocrine carcinoma of the prostate gland with pelvic lymph node metastasis: a case report with review of literature.

Neuroendocrine (NE) differentiation in prostate carcinomas can be seen in two settings: as a focal finding in conventional acinar adenocarcinoma, identifiable by immunohistochemical staining, or as a primary NE tumor of the prostate gland, such as carcinoid, small cell carcinoma, or large cell NE carcinoma. Of particular interest is the large cell NE carcinoma, which had been previously reported in isolated cases or in limited case series. In this report, we describe a case of a large cell NE carcinoma diagnosed in a 48-year-old man who presented with difficulty in voiding and urine retention. A cystoscopy revealed an enlarged, elongated prostate with an intra-urethral obstructing mass in the prostatic urethra. Subsequently, a transurethral resection of prostate (TURP) was performed at an outside hospital under the clinical diagnosis of benign prostatic hyperplasia (BPH). Microscopic examination of the TURP specimen revealed several foci of low-grade transitional-zone-type adenocarcinoma corresponding to Gleason score 5 (3 + 2), and a focus of high-grade large cell NE carcinoma. Concurrent x-ray computed tomography scans of the chest, abdomen, and pelvis demonstrated an enlarged left pelvic lymph node, which was biopsied and the patient was diagnosed with metastatic large cell NE carcinoma. He subsequently underwent 8 cycles of neoadjuvant chemotherapy with Lupron, a laparoscopic robotic-assisted radical retropubic prostatectomy, and pelvic lymphadenectomy. He died of widely metastatic prostatic carcinoma with leptomeningeal metastases 13 months after radical prostatectomy. Here, we present a rare case of large cell NE carcinoma with a review of the published literature.