Enhanced myometrial vascularity: case presentation and review.

OBJECTIVE: To describe the etiology of arteriovenous malformations (AVM) and enhanced myometrial vascularity (EMV), and review updates in management for patients with retained products of conception (RPOC) associated with EMV through a case presentation. DESIGN: A 6-minute narrated video discusses the recent distinction between EMV and AVM. The etiology, symptoms, imaging findings/interpretation, and management based on symptoms are reviewed in detail. As this represents a single case report, it does not meet the definition of research according to the regulations at 45 CFR 46.102(l); therefore, institutional review board approval was not required. SETTING: Tertiary referral center. PATIENT(S): Eight weeks after suction dilation and curettage (D&C) for an incomplete abortion, a 28-year-old gravida 1, para 0 patient presented to an outside facility with RPOC, menorrhagia, and an acute decrease in hemoglobin. After uterine AVM was diagnosed, she was transferred to our facility for further care. INTERVENTION(S): After transfer to our center, ultrasound demonstrated RPOC, with prominent internal vasculature containing peak systolic velocity >20 cm/s. A diagnosis of EMV was made. Magnetic resonance imaging confirmed a prominent serpentine vessel at the endometrium and RPOC within the uterine cavity (Fig. 1). Due to her anemia, she underwent uterine artery embolization (UAE) followed by suction D&C (Fig. 2). Hysteroscopy was performed before and after suction D&C and after curettage, a large vascular bundle was appreciated at the surface of the endometrium. MAIN OUTCOME MEASURE(S): None. RESULT(S): The patient presented to the clinic 2 weeks postoperatively with the resolution of abnormal uterine bleeding symptoms and a negative ß-human chorionic gonadotropin test. CONCLUSION(S): Management of patients with EMV is dependent on the extent of their symptoms. If significant bleeding is present, surgical management is required. Previous reports suggested that patients with EMV and RPOC should undergo UAE before D&C, but more recent studies suggest that D&C may be initiated without UAE, as EMV associated with RPOC may be a normal transient placentation phenomenon and have less risk of hemorrhage than previously suspected. However, in patients with significant preoperative bleeding and/or anemia, we propose that UAE should still be considered. Each patient requires individualized management based on symptoms, signs, imaging, and plans for future fertility. The ideal management of patients with RPOC and EMV remains to be determined.

Acute pelvic pain following miscarriage heterotopic pregnancy must be excluded: case report.

BACKGROUND: Heterotopic pregnancies are increasing in prevalence and this case highlights the importance of excluding the diagnosis in patients with pelvic pain following miscarriage. A known pre-existing intrauterine pregnancy can be falsely reassuring and delay the diagnosis of a potentially life-threatening concurrent ectopic pregnancy. CASE PRESENTATION: In this report, we describe a case of spontaneous heterotopic pregnancy in a woman who had initially presented with pelvic pain and vaginal bleeding, and was diagnosed on pelvic ultrasound with a missed miscarriage; a non-viable intrauterine pregnancy. She re-presented 7 days later with worsening pelvic pain and bleeding, and a repeat pelvic ultrasound identified a ruptured tubal ectopic pregnancy in addition to an incomplete miscarriage of the previously identified intrauterine pregnancy. She underwent an emergency laparoscopy where a ruptured tubal ectopic pregnancy was confirmed. CONCLUSION: Being a time critical diagnosis with the potential for an adverse outcome, it is important that the emergency physician considers heterotopic pregnancy as a differential diagnosis in patients presenting with pelvic pain following a recent miscarriage. The same principle should apply to pelvic pain in the context of a known viable intrauterine pregnancy or recent termination of pregnancy. A combination of clinical assessment, beta human chorionic gonadotropin levels, point of care ultrasound and formal transvaginal ultrasound must be utilized together in these situations to explicitly exclude heterotopic pregnancy.

Comparison of the diagnostic value of histopathological examinations of miscarriage products after pharmacological induction of miscarriage and curettage.

OBJECTIVES: For early miscarriage (pregnancy loss ≤ 12 weeks of gestation), two types of therapeutic treatment are offered (pharmacotherapy and curettage of the uterine cavity) depending on the presence and severity of clinical symptoms as well as patient choice. Our study aimed to assess the diagnostic value of the results of histopathological examinations of miscarriage products in relation to the administered treatments. MATERIAL AND METHODS: 850 medical records from patients diagnosed with missed miscarriage or empty gestational sac were analyzed retrospectively. Patients underwent surgical treatment or pharmacotherapy. Inefficacy of pharmacotherapy resulted in subsequent curettage. The results of histopathology were evaluated for their diagnostic value and classified: subgroup 1 - high value specimen (the studied specimen included fetal tissues, and villi), and subgroup 2 - no-diagnosis (the studied specimen included maternal tissues, autolyzed tissues, blood clots). Data were compared with chi-squared test. Differences was considered significant at p < 0.05. RESULTS: 1128 histopathological test results were analyzed; 569 (50.4%) were obtained during pharmacotherapy and 559 (49.6%) after curettage; out of the latter 497 after the initial pharmacotherapy and 62 after surgery. In the pharmacotherapy group, high value specimens comprised 231 cases (40.59%) while no diagnosis was obtained in 338 cases (59.4%). Considering specimens obtained in the course curettage, high value specimens were found in 364 cases (65.1%) while results that did not allow a diagnosis to be made were found in 195 cases (34.9%). CONCLUSIONS: Tissue specimens of high diagnostic value are obtained significantly more often during surgical treatment of miscarriage than during pharmacotherapy.

Clinical and imaging predictors of management in retained products of conception.

OBJECTIVES: To determine if clinical and ultrasound (US) imaging features help predict management in clinically suspected retained products of conception (RPOC). METHODS: 334 patients sonographically evaluated for RPOC were included in this IRB-approved retrospective study. Of the 334 patients, 176 had sonographic diagnosis of RPOC and comprised the final study group. Patients were managed expectantly, medically, or surgically in accordance with clinical judgment of treating physicians. Pelvic sonograms were retrospectively reviewed for endometrial stripe thickness and vascularity was graded on a 0-3 scale based on appearance relative to myometrium (Grade 0: no vascularity, Grade 1: minimal vascularity, Grade 2: moderate vascularity, Grade 3: marked vascularity). Clinical and imaging predictors of management were evaluated in univariate and multivariate analysis. RESULTS: Mean patient age was 29.6 years and mean gestational age was 17.4 weeks. Most (74.4%) women presented with vaginal bleeding. 83 patients (47.2%) were treated conservatively with expectant management, 42 (23.8%) were treated medically, and 51 (29.0%) required surgical intervention. Mean endometrial stripe thickness was 21.3 mm. 47 women (26.7%) had vascularity score of 0; 50 (28.4%) had score 1; 52 (29.6%) had score 2; and 27 (15.3%) had score 3. In univariate analysis, serum hemoglobin (Hb) (p < 0.0001), endometrial stripe thickness on US (p < 0.005), presenting symptoms (p = 0.03), and US vascularity score (p < 0.005) were statistically significant predictors of final management. In multivariate logistic regression, serum Hb (OR 0.69, 95% CI 0.55-0.86, p < 0.0009), endometrial stripe thickness (OR 1.08, 95% CI 1.04-1.12, p < 0.0001), and US vascularity score (OR 1.77, 95% CI 1.16-2.70, p < 0.01) were statistically significant predictors of need for surgery. CONCLUSIONS: Serum Hb, endometrial stripe thickness, and US vascularity score were significant predictors of clinical management, particularly the need for surgical intervention, in women with clinically suspected RPOC.

Effects of leonurine hydrochloride on medically induced incomplete abortion in early pregnancy rats.

OBJECTIVES: To determine the effect of leonurine hydrochloride (LH) on abnormal bleeding induced by medical abortion. STUDY DESIGN: Rats had incomplete abortions induced in early pregnancy using mifepristone in combination with misoprostol. After abortion, rats were treated with LH for 7 days, and the duration and volume of uterine bleeding were observed. Approximately 30min after the last treatment, the animals were killed and the uterine shape was observed. The sinistro-uteri were suspended in organ baths to record the contraction curves, including the frequency and tension for 10min; the dextro-uteri were fixed with formaldehyde for pathologic evaluation. In addition, blood samples were collected from the femoral artery for the measurement of estradiol (E2) and progesterone (P) levels by radioimmunoassay. RESULTS: In in vivo experiments, compared with the model group, LH treatment markedly reduced the volume of bleeding and intrauterine residual, and significantly shortened the duration of bleeding. From the contraction curve, LH notably reinforced the frequency and tension of uterine contractions. LH remarkably elevated the serum estradiol level in rats, but had no obvious effect on progesterone level. CONCLUSIONS: LH has an inhibitory effect on bleeding caused by incomplete abortion; the mechanism may be related to up-regulation of the E2 level, leading to an increase in uterine contractions and evacuation of intrauterine residuum.

Best predictors of grayscale ultrasound combined with color Doppler in the diagnosis of retained products of conception.

OBJECTIVES: To determine the best predictors of the presence of retained products of conception (RPOC) on grayscale and color Doppler transvaginal sonographic examination. METHODS: This was a retrospective study of 91 consecutive patients who underwent transvaginal sonography (TVS) with color Doppler to evaluate for the presence of RPOC. The images of TVS studies were reviewed by two radiologists in consensus blinded to the final outcome. Data on a number of variables including endometrial measurable mass and focal increased color vascularity were collected as predictors of RPOC. The patients' ages ranged from 17 to 48 years (mean, 31.8 ± 6.8) and gestational age from 5 to 24 weeks (mean, 9.2 ± 3.8). Thirty-six were confirmed as RPOC by dilatation and curettage (D&C) and pathology. Fifty-five were considered negative, 9 based on D&C results and 46 on clinical grounds. RESULTS: Sensitivity, specificity, negative- and positive-predictive and accuracy values were 81% (CI: 68%-94%), 71% (CI: 59%-83%), 85% (CI: 74%-95%), 64% (CI: 50%-78%), and 75% (CI: 66%-84%) to detect RPOC when a mass was present. The corresponding numbers for the presence of focal color vascularity were 94% (CI: 87%-100%) (p = 0.07), 67% (CI: 55%-80%) (p > 0.05), 95% (CI: 88%-100%) (p = 0.1), 65% (CI: 52%-78%) (p > 0.05), and 78% (CI: 70%-87%) (p > 0.05). Of the patients with confirmed RPOC on pathology, five had focal increased vascularity and no massand none had a mass without focal increased vascularity. CONCLUSION: An area of focal increased vascularity with or without a mass is the best predictor of the presence of RPOC.

Management of retained products of conception with marked vascularity.

Cases of retained products of conception (RPOC) with marked vascularity present a clinical challenge because simple dilation and curettage (D&C) can lead to life-threatening hemorrhage. We describe here two cases of hypervascular RPOC that were successfully managed with two different approaches. Case 1: A 26-year-old woman with history of 3 D&Cs was transported to the emergency room for heavy vaginal bleeding 45 days after a spontaneous abortion. Diagnosis of RPOC with aneurysm-like structure was considered and uterine artery embolization was performed. Four days after the uterine artery embolization, reduction of the vascularity of RPOC was confirmed on color Doppler ultrasonography and D&C was successfully carried out. Case 2: A 37-year-old woman with history of one cesarean section became pregnant after the regular menses. She underwent D&C for missed abortion at 8 weeks' gestation. Seven days after the D&C, sonographically heterogenous mass emerged in the vicinity of the previous cesarean scar. Thereafter, the mass gradually grew larger and diagnosis of hypervascular placental polyp was considered. As the amount of vaginal bleeding was small, expectant management was instituted. Sixty-one days after the first D&C, reduction of the vascularity of RPOC was confirmed on color Doppler ultrasonography and D&C was successfully completed.

Role of clinical and ultrasound findings in the diagnosis of retained products of conception.

OBJECTIVE: To assess the role of clinical and ultrasound findings as predictors of retained products of conception (RPOC) in women with a suspicion of incomplete miscarriage. METHODS: This was a retrospective study of 91 patients admitted for suspected RPOC after spontaneous first-trimester miscarriage who were evacuated surgically, and for whom histopathological reports were available. All the women underwent transvaginal sonography after their miscarriage. The decision to evacuate the uterus was based on vaginal bleeding, lower abdominal pain and/or sonographic findings of hyperechoic material or endometrial thickness more than 8 mm. Maternal age, gestational age, clinical signs and symptoms and sonographic findings were recorded. Clinical and sonographic findings were compared with the histopathological reports and the sensitivity and specificity of vaginal bleeding, abdominal pain and sonographic appearance of the endometrium for detecting the products of conception were assessed. RESULTS: Histopathological analysis confirmed the presence of chorionic villi in 55 women (60%) and decidua in 36 (40%). Vaginal bleeding was more frequent in women with RPOC (P < 0.001), whilst lower abdominal pain was a more frequent symptom in those with decidua (P = 0.019). The ultrasound finding of hyperechoic material had a sensitivity of 78%, specificity of 100% and positive and negative predictive values of 100% and 75%, respectively, in predicting RPOC. Vaginal bleeding as a predictor of RPOC had a sensitivity of 93%, specificity of 50%, and positive and negative predictive values of 74% and 82%, respectively. The combination of hyperechoic material and/or vaginal bleeding increased the sensitivity to 98% and negative predictive value to 95%. There was no significant difference in endometrial thickness between the two groups. CONCLUSION: The ultrasound finding of hyperechoic material is the best predictor for diagnosing RPOC. In the absence of hyperechoic material and vaginal bleeding, RPOC are extremely unlikely.

A probable secondary infertility due to osseous metaplasia of the endometrium.

OBJECTIVE: Osseous metaplasia is a rare pathological entity that affects the uterus and usually appears following abortion, chronic endometritis, metabolic disorders or following LEEP excision of the cervix. CASE: Herein, we present the occurrence of osseous metaplasia in a 27-year-old patient with a history of an abortion 2 years ago and suffering infertility. CONCLUSION: We suggest that the infertility in this patient may be caused by calcification and ossification of fetal tissue retained in the uterus after abortion.

The value of measuring endometrial thickness and volume on transvaginal ultrasound scan for the diagnosis of incomplete miscarriage.

OBJECTIVE: To identify ultrasound measurements that are the best predictors of the presence of retained products of conception (RPOC) within the uterine cavity in women with clinical diagnosis of incomplete miscarriage. METHODS: This was a prospective observational study, set in a dedicated early pregnancy assessment unit in a London teaching hospital. Endometrial thickness and the volume of suspected retained products of conception were measured by transvaginal ultrasound scan preoperatively. Indications for surgical intervention were heavy vaginal bleeding or continuous bleeding lasting > 7 days. The main outcome measure was histological evidence of chorionic villi in surgical specimens. RESULTS: Among the patients, 109 (85%) had evidence of chorionic villi on histology, whilst decidua was only found in the remaining 19 (15%). There was no identifiable cut-off for endometrial thickness or volume that could be used to differentiate between retained products of conception and decidua. CONCLUSION: Measurements of endometrial thickness or volume on ultrasound scan are not good tests for diagnosing an incomplete miscarriage.

Routine histopathologic analysis of product of conception following first-trimester spontaneous miscarriages.

AIM: To evaluate the histopathologic findings relating to tissue samples collected at surgical uterine evacuation in first-trimester spontaneous miscarriages. METHODS: In this retrospective study, histopathologic diagnosis of the tissue samples obtained via surgical uterine evacuation in patients who were admitted to the Early Pregnancy Clinic in a 12-month period with the diagnosis of incomplete miscarriage (n = 970), missed miscarriage (n = 406) and anembryonic miscarriage (n = 230) in the first trimester was recorded and compared with the presurgery diagnosis. RESULTS: Uterine evacuation was performed in cases of incomplete miscarriage (n = 970, 60.4%), missed miscarriage (n = 406, 25.2%) and anembryonic miscarriage (n = 230, 14.3%). Histopathologic examination revealed the product of conception in 1119 patients (69.7%), while partial hydatidiform mole was diagnosed in 33 patients (2.1%). Complete hydatidiform mole was detected in only seven cases (0.43%). Exaggerated placental site and placental site trophoblastic nodule was detected in two cases (0.12%). Decidual tissue without chorionic villi was reported in 272 patients (16.9%), raising the suspicion of presence of other pathology. CONCLUSIONS: By routine histopathologic assessment of products of first-trimester spontaneous miscarriages, important pathologies such as molar pregnancy and placental trophoblastic disease can be diagnosed. Histopathological assessment has great value in the identification of an ectopic pregnancy or infection when compared with clinical and laboratory findings.

The role of ultrasound imaging in diagnosing and investigating early pregnancy failure.

The advent of high-resolution transvaginal ultrasound (TVS) has revolutionized our understanding of the pathophysiology and the management of early pregnancy failure. Knowledge of the ultrasound appearances of normal early pregnancy development and a good understanding of its pitfalls are essential for the diagnosis and management of early pregnancy failure. Ultrasound imaging has rapidly replaced all other techniques used to study normal human development in the first trimester, and ultrasound features of the early gestational sac have corroborated anatomical studies showing that the first structures to appear are the celomic cavity and the secondary yolk sac. No single ultrasound measurement of the different anatomical features in the first trimester has been shown to have a high predictive value for determining early pregnancy outcome. Similarly, Doppler studies have failed to demonstrate abnormal blood flow indices in the first-trimester uteroplacental circulation of pregnancies that subsequently end in miscarriage. Ultrasound parameters combined with maternal serum hormone levels, maternal age, smoking habits, obstetric history and the occurrence of vaginal bleeding have all been combined in multivariate analyses, with mixed results. Combined ultrasound and in-vitro experiments have demonstrated that the maternal circulation inside the placenta starts at the periphery at around 9 weeks of gestation and that this is associated with a physiological oxidative stress which could be the trigger for the formation of the placental membranes. Abnormal development of these membranes can result in subchorionic hemorrhage and threatened miscarriage with subsequent long-term consequences such as preterm rupture of the membranes and preterm labor, irrespective of the finding of a hematoma on ultrasound. In both euploid and aneuploid missed miscarriages there is clear ultrasound evidence for excessive entry of maternal blood at a very early stage inside the developing placenta resulting in oxidative stress and subsequent degeneration of villous tissue. The finding of blood flow in the intervillous space in cases of first-trimester miscarriage using color Doppler also appears to be useful in the prediction of success of expectant management. Miscarriages with blood flow within the intervillous space are up to four times more likely to complete with expectant management. TVS is considered the gold standard in the diagnosis and management of incomplete miscarriage. Expectant management of miscarriage, using ultrasound parameters to determine eligibility, could significantly reduce the number of unnecessary evacuations of the retained products of conception, depending on the criteria used.

MR imaging of maternal diseases of the abdomen and pelvis during pregnancy and the immediate postpartum period.

Magnetic resonance (MR) imaging provides multiplanar large field-of-view images of the body with excellent soft-tissue contrast and without ionizing radiation. As a result, MR imaging is increasingly being used to image the maternal abdomen and pelvis during and immediately after pregnancy. Results of rapid T1- and T2-weighted imaging are often diagnostic, and blood vessels, ductal structures, and the urinary tract can frequently be visualized without intravenous administration of contrast material. Until more conclusive safety data become available, MR imaging should be reserved for cases in which results of ultrasonography are inconclusive and patient care depends on further imaging. In the setting of acute abdomen during pregnancy, MR imaging allows identification of areas of inflammation, abscess formation, hemorrhage, and bowel obstruction. MR imaging also helps determine the organ of origin, extent, and composition of maternal neoplasms and is useful in evaluation of müllerian duct anomalies and abnormalities of placental formation, position, and implantation. Many postpartum complications such as retained products of conception and uterine dehiscence may be diagnosed with MR imaging when results of other modalities are indeterminate.

Novel treatment of a patient with secondary infertility due to retained fetal bone.

OBJECTIVE: To describe a simple and previously unreported treatment for retained fetal bone fragments as a cause of secondary infertility. SETTING: Fertility center at a Canadian teaching hospital. DESIGN: Case report. PATIENT(S): A 36-year-old woman with a 15-year history of secondary infertility. INTERVENTION(S): A second dilation and curettage (D+C) performed under abdominal ultrasound guidance was performed where the curette could be directed for the removal of echogenic endometrial foci. MAIN OUTCOME MEASURE(S): Resolution of long-term infertility. RESULT(S): Spontaneous pregnancy 4 months after ultrasound-guided D+C and subsequent term delivery. CONCLUSION(S): If an echogenic area is discovered in the endometrium, it is now standard to look at the uterine cavity by hysteroscopy. However, if the hysteroscopy is normal, we suggest that a D+C with intraoperative abdominal ultrasound assistance be done to ensure that all the abnormal tissue is removed.

Histological analysis of the products of conception following first trimester abortion at Jordan University Hospital.

OBJECTIVE: To evaluate the value of histopathological examination of products of conception in first trimester abortion. SETTINGS: University hospital. DESIGN: Retrospective record review over 2 years, from January 1999 to January 2001. PATIENTS: A total number of 293 patients with the diagnosis of first trimester abortion were admitted and their abnormal pregnancy evacuated. RESULTS: The highest type of abortion among the studied group was incomplete abortion, 140 patients (48%), and surgical evacuation was the most common method of termination, 202 patients (69%). The histopathology reports confirmed the pregnancy in all patients and revealed partial mole in 51 patients (17%), undiagnosed abnormality in 8 patients (2.7%), suggesting the possible cause for recurrent pregnancy loss in 4 patients (1.4%). CONCLUSION: Histopathological assessment for the products of conception proved to be an important tool in detecting molar pregnancy and hydropic changes that necessitate special follow-up protocol and unmasking ectopic pregnancies for further management.

[Uterine leiomyosarcoma with subsequent pregnancy]. / Uterine Leiomyosarkome mit nachfolgender Schwangerschaft.

Leiomyosarcoma are malignant tumors showing smooth muscle differentiation, they are rare, representing only about 25 percent of all uterine sarcomas and mixed malignant tumors and slightly more than 1 percent of all corporeal malignant tumors. Usually they arise in postmenopausal women and are not known to be related to the known risk factors for endometrial carcinoma (nulliparity, obesity, diabetes mellitus, hypertension, etc.) or carcinosarcoma (prior radiation therapy). They may occur in uteri that also bear typical benign leiomyomas, but leiomyosarcoma rarely can be proven to have arisen in or from benign leiomyomas. We report on two premenopausal women with leiomyosarcoma--out of totally 31 cases in our clinic from 1975-1995 who got pregnant after surgical treatment preserving the uterus. The patients are alive without evidence of disease 3 and 6 years after surgical resection.

Mola incompleta: incidencia / Incomplete mole: incidence

La mola incompleta se diagnóstica en más del 90 por ciento de los casos posterior al estudio histológico proveniente de los legrados uterinos de pacientes con diagnóstico preoperatorio de aborto incompleto. La incidencia reportada es de 1 en 695 embarazos. Se incluyeron en un estudio prospectivo 514 pacientes ingresadas a la Maternidad Concepción Palacios con diagnóstico de aborto incompleto, tomando muestra del tejido obtenido mediante legrado uterino. Se encontró una incidencia de mola incompleta de 1,16 por cada 100 abortos incompletos. El hallazgo de mola incompleta se determinó en 6 casos, ocurriendo dicha entidad en primigestas en un 50 por ciento de las pacientes y con edades comprendidas entre 16 y 20 años en 66,66 por ciento. Se evaluó además la clínica asociada encontrándose que el 83,33 por ciento de las pacientes consultaron por sangrado genital. En el 2,33 por ciento se diagnosticaron patologías ginecológicas

[Contemporary biopsy for diagnosis of abortion residues: preliminary experience]. / Biopsia contemporánea para el diagnóstico de restos de aborto: experiencia preliminar.

The differential diagnosis between abortion and ectopic pregnancy has important clinical implications. In this report we have tested the accuracy of frozen sections in uterine curettings to identify intrauterine pregnancy. Uterine curettings with a diagnosis of products of gestation, from 104 patients were studied. In all of them plasmatic levels of B Gonadotrophin were measured. The curetting material was fixed and studied on frozen sections and on paraffin embedded tissue. A high positive relationship between frozen and embedded material was observed. The sensibility, specificity, positive and negative predictive value of the frozen section to detect chorionic villi were 90.6; 100; 100 and 74% for each of them.

The usefulness of human placental lactogen and keratin immunohistochemistry in the assessment of tissue from purported intrauterine pregnancies.

This study compared conventional light microscopy with immunohistochemistry in the histopathologic diagnosis of intrauterine pregnancy in curettings in which fetal parts and chorionic villi were absent. Hematoxylin and eosin-stained sections of the curettings, which were from 50 consecutive patients in whom incomplete abortion had been diagnosed clinically, were circulated to four pathologists who graded their diagnoses with a confidence score. Immunohistochemical examination using a standard streptavidin-biotin-peroxidase method with anti-HPL and antikeratin antisera was performed. The pathologists in the maternity hospitals achieved a high level of diagnostic confidence compared with those working in the general hospitals. However, there were erroneous diagnoses by the one pathologist in the former group and none by the latter. Critical path analysis showed that the best performing pathologist could accurately diagnose all but two of the cases that had been diagnosed with a degree of doubt by the other pathologists without recourse to immunohistochemical examination. These results suggest that immunohistochemistry may be used discriminately in uncertain cases or if relatively inexperienced pathologists are reporting.