HLA-G is expressed by the glandular epithelium of peritoneal endometriosis but not in eutopic endometrium.

BACKGROUND: HLA-G is a major histocompatability antigen with documented immune-regulatory function. Various epithelial cancers and tissue allografts have been noted to express HLA-G, which is postulated to aid in their escape from immunosurveillance. We evaluated peritoneal endometriosis and eutopic endometrium for the expression of HLA-G protein and gene transcript. METHODS: Two experiments were performed: (i) archived tissue blocks from peritoneal endometriotic lesions (n = 15) and eutopic endometrium (n = 12) were evaluated for extent of protein immunostaining, and (ii) eutopic endometrial biopsies from women without (n = 17) and with (n = 24) endometriosis, and peritoneal endometriotic lesions (n = 14) were evaluated for presence of RNA transcript by in situ hybridization. RESULTS: HLA-G protein localized in the glandular epithelium of 14 of 15 (93.3%) peritoneal endometriotic lesions, but not in stromal cells. HLA-G protein staining was absent in endometrial biopsies (n = 12). HLA-G gene transcript localized to the glandular epithelium in 13 of 14 (92.8%) peritoneal endometriotic lesions. HLA-G transcript was never observed in eutopic endometrium, regardless of cycle stage or whether from women with (n = 24) or without (n = 18) endometriosis. CONCLUSIONS: HLA-G is expressed by endometriotic glandular epithelium but not by eutopic endometrium under normal conditions. Differential expression of HLA-G suggests that peritoneal inflammation or cellular stress may up-regulate mechanisms to promote ectopic endometrial survival.

Heterotopic bone in the ovary associated with a mucinous cystadenoma.

Bone formation in the ovary, with the exception of developing in the setting of a mature cystic teratoma, is exceedingly uncommon. We report a case of bone formation within a mucinous cystadenoma of the ovary. A 19-year-old active duty female presented with an asymptomatic pelvic mass; sonographic imaging revealed a 5.7-cm complex right adnexal mass. A laparoscopic cystectomy was performed. Pathologic evaluation of the cyst revealed a mucinous cystadenoma. Contained within several of the thick fibrous septae were areas of well-formed bone. Although a benign finding, bone formation and associated fibrosis may lead to sonographic findings of concern during the evaluation of patients with a pelvic mass.

Spindle cell lipoma of the female genital tract. A report of two cases.

BACKGROUND: Lipomas presenting in the female genital tract are most commonly seen in the vulva or myometrium as a component of a leiomyoma. These lesions have the gross appearance of a typical lipoma. CASES: Two cases of spindle cell lipoma occurred, one incidentally encountered in the cervix and the other presenting as a vulvar mass. Both lesions demonstrated histologic features characteristic of spindle cell lipomas normally found elsewhere, and the diagnosis was supported by immunohistochemical staining patterns. CONCLUSION: This is the first report of spindle cell lipomas diagnosed in the female genital tract.

Placenta increta/percreta associated with uterine perforation during therapy for fetal death. A case report.

BACKGROUND: Placenta accreta involves abnormal adherence of the placenta to the myometrium. Placenta increta and percreta are defined by the degree of trophoblastic penetration of the myometrium. These conditions are rarely observed in the first trimester; placenta increta and percreta are exceptionally infrequent. CASE: A woman had a uterine perforation after suction curettage for fetal death at 11 weeks' gestation, requiring hysterectomy for control of a profuse hemorrhage. Histopathologic examination of the uterus revealed placenta increta involving the lower uterine segment and placenta percreta at the site of uterine perforation. CONCLUSION: This is the first report of placenta percreta associated with uterine perforation during therapy for first-trimester fetal death.

Use of desmin immunohistochemistry to distinguish between mesothelial cells and carcinoma in serous fluid cell block preparations.

OBJECTIVE: To evaluate the utility of immunohistochemical stains for desmin in discriminating mesothelial cells from adenocarcinoma in serous fluid cell block preparations. STUDY DESIGN: Cell block preparations from 22 cases (representing 18 patients) that were positive for carcinoma and 5 cases that were negative for malignancy were immunostained with an antibody to desmin. Positive staining was evaluated and scored semiquantitatively in both tumor cells and background mesothelial cells in the malignant cases and mesothelial cells in the negative controls. Staining was evaluated with a score of 0-3 for intensity and 0-5 for distribution. The sum of the two scores was recorded as the total score (TS). RESULTS: Mesothelial cells from all the carcinoma and benign cases stained with desmin (median TS = 5.5, range 4-8), typically strong in intensity and widespread in distribution. Positivity was observed in carcinoma cells in all cases, typically weak and focal (range 2-4). Using a total score of 4 as a cutoff for definitively positive staining, desmin staining was positive in mesothelial cells in 25/25 cases and carcinoma cells in 1/22 cases (P < .0001, Fisher's exact test). Additionally, using the Mann-Whitney ranked sum test on the 20 cases with evaluable mesothelial cells, the medians of the total scores for mesothelial cells (5.5) and carcinoma cells (2.5) were significantly different (P < .0001). CONCLUSION: A total score of > or = 4 was significantly associated with mesothelial cell staining. Use of desmin immunohistochemical staining in cell block preparations may be helpful in distinguishing between mesothelial cells and carcinoma.

Reproducibility of the diagnosis of endometrial hyperplasia, atypical hyperplasia, and well-differentiated carcinoma.

Many studies have attempted to identify histologic features that aid in the distinction of atypical hyperplasia (AH) from hyperplasia without atypia and well-differentiated endometrioid carcinoma, but few have evaluated the reproducibility of these diagnoses. Five pathologists independently reviewed 100 endometrial biopsy and curettage specimens chosen to represent the entire spectrum of proliferative lesions of the endometrium, including proliferative endometrium (PEM), hyperplasia without atypia, AH, and well-differentiated endometrioid carcinoma. Slides were reviewed twice for diagnosis, with an intervening evaluation of a checklist of histologic features. Intraobserver and interobserver agreement were assessed using the kappa statistic. Intraobserver kappa values ranged from 0.67 to 0.89 (76% to 89% agreement). Interobserver kappa values by diagnostic category were: proliferative endometrium: 0.86; hyperplasia without atypia: 0.60; AH: 0.47; well-differentiated endometrioid carcinoma: 0.83; with a kappa value of 0.69 for all cases combined. Associations between the selected histologic features and the given diagnoses for each pathologist were analyzed using multiple logistic regressions to identify features that were useful for distinguishing among diagnostic categories. Histologic features determined by univariable and multivariable analyses that were found to be most associated with distinguishing diagnostic categories were: proliferative endometrium versus hyperplasia without atypia: gland crowding (univariable, multivariable), and gland branching (univariable); hyperplasia without atypia versus AH: presence of nucleoli (univariable, multivariable), nuclear enlargement (univariable), vesicular chromatin change (univariable), nuclear pleomorphism (univariable), chromatin irregularities (univariable), and loss of polarity (univariable); hyperplasia without atypia versus carcinoma: glandular confluence/complex cribriform pattern (univariable, multivariable), stromal alteration (univariable, multivariable), and necrosis (univariable). In summary, interobserver agreement was good but was lowest for AH. Only the presence of nucleoli was strongly associated with distinction of AH from hyperplasia without atypia. Individual pathologists use additional features to diagnose atypia, but these features are not consistently associated with that diagnosis. Cribriform architectural pattern and stromal alteration were associated with the distinction of well-differentiated endometrioid carcinoma from AH.

Ischemic fasciitis. Report of a case with fine needle aspiration findings.

BACKGROUND: Ischemic fasciitis, also called atypical decubital fibroplasia, was recently described as a distinctive fibroblastic proliferation occurring predominantly in elderly, bed-ridden individuals. This entity can easily be misdiagnosed as a malignant process. CASE: A 70-year-old, white male presented with an enlarging right hip mass. Fine needle aspiration yielded spindled and ovoid cells with ample cytoplasm and occasional nuclear atypia. The histologic features of a subsequent biopsy and resection specimen included a zonal pattern of fibrinoid necrosis with surrounding reactive fibroblasts, histiocytes and vascular proliferation, which are characteristic of ischemic fasciitis. CONCLUSION: Ischemic fasciitis can be mistaken clinically, cytologically and histologically for sarcoma. The cytologic findings seen in this case, when combined with the clinical history, were sufficient to avoid misdiagnosis of malignancy in a benign, proliferative lesion.