False-positive pregnancy test secondary to ectopic expression of human chorionic gonadotropin by a gastrointestinal stromal tumor

False-positive urine pregnancy screening tests are uncommon in the hospital setting among patients with bowel-containing urinary tract reconstruction

PURPOSE

False-positive urine pregnancy screening tests (UPST) have been reported among patients with bowel-containing urinary reconstruction (BCUR). However, the true frequency of such inaccurate results, which have been attributed to urinary mucous or other proteins interfering with or mimicking the binding of beta-HCG in the assay, is unknown in this population. We sought to determine the incidence of false-positive pregnancy screening tests among this patient population at our institution.

MATERIALS AND METHODS

Using existing databases of patients with spina bifida, bladder exstrophy, and genitourinary rhabdomyosarcoma, we identified female patients with BCUR who had UPST over a 10-year period as screening prior to procedures or imaging. Patient and test result information was recorded.

RESULTS

A total of 120 patients with a history of BCUR were identified: 33 with spina bifida, 73 within the exstrophy-epispadias complex (EEC), and 14 with genitourinary rhabdomyosarcoma. Of this group, 46 patients (38%) had at least one UPST during the study period; 15 had 1 UPST, 6 had 2 UPSTs, 4 had 3 UPSTs, and 21 had greater than 3 UPSTs, for a total of 244 UPST in this cohort. UPSTs used at our institution included Sure-Vue brand and Alere brand (HCG sensitivity 20 mIU/ml). Types of BCUR included ileal enterocystoplasty in 25 patients, colon enterocystoplasty in 6, stomach enterocystoplasty in 5, composite enterocystoplasty in 7, and continent catheterizable channel alone (e.g. Yang-Monti, appendicovesicostomy) in 3 patients. Of the 244 UPSTs in patients with BCUR, zero (0%) were positive.

CONCLUSIONS

Despite reports in the literature that false-positive UPST are common among patients with bowel-containing urinary diversions, we found no positive UPST among patients with BCUR in the healthcare setting. False-positive UPST in the home setting may be due to variability in sensitivity thresholds, binding agents, technical errors in test technique, kit quality control, or other factors.

False positive pregnancy tests in pediatric patients with augmentation enterocystoplasty

PURPOSE

Our primary aim was to determine the prevalence of positive over-the-counter (OTC) pregnancy tests among pediatric female and male patients who had undergone augmentation enterocystoplasty. A secondary aim was to determine whether patient factors or urinalysis (UA) results were associated with false positive OTC pregnancy test results in patients with a history of augmentation enterocystoplasty.

METHODS

Patients at a tertiary pediatric hospital who had previously undergone augmentation enterocystoplasty, Mitrofanoff appendicovesicostomy only, and age- and sex-matched controls were prospectively recruited. Urine samples were obtained, and two OTC pregnancy tests were conducted - OTC Test A reported the ability to detect pregnancy at hCG levels as low as 9.6 mIU/mL, while OTC Test B reported positive pregnancy test results at hCG levels ≥25 mIU/mL. A point of care (POC) pregnancy test and UA were also completed. Mann-Whitney U tests and Fisher's exact tests were used to assess whether patient factors or UA results were associated with false positive pregnancy test results.

RESULTS

Fifty pediatric patients were enrolled, including 20 with augmentation enterocystoplasty, 20 age- and sex-matched controls, and 10 with Mitrofanoff appendicovesicostomy only. Among the 20 patients who had undergone augmentation cystoplasty, 15 (75.0%) had positive pregnancy test results on OTC Test A, including 11/13 (84.6%) females and 4/7 (57.1%) males. No control patients or patients with Mitrofanoff appendicovesicostomy only had a positive test. No patients had positive pregnancy test results on OTC Test B or the POC test. While patients with augmentation enterocystoplasty were significantly more likely to test positive for blood (p = 0.01), nitrate (p = 0.03), and leukocytes (p < 0.0001), these factors were not significantly associated with false positive pregnancy results. No patient factors or UA results were associated with increased likelihood of false positive OTC pregnancy test results.

CONCLUSIONS

These findings indicate that sensitive OTC pregnancy tests that detect low quantities of hCG in urine may result in false positive results among patients who have undergone augmentation enterocystoplasty. Female patients of reproductive age with bladder augmentations should be counseled regarding appropriate pregnancy testing options. Additional research is needed to determine the mechanism responsible for false positive pregnancy tests in this patient population.

Radiotherapy in the Management of Gastrointestinal Stromal Tumors: A Systematic Review

Simple Summary

Gastrointestinal stromal tumors are considered to be insensitive to radiotherapy. However, with the development of radiation techniques and the accumulation of cases, some studies have indicated that radiotherapy could help achieve objective response in advanced or metastatic gastrointestinal stromal tumors. Therefore, it is necessary to conduct a systematic review to reassess the role of radiotherapy in gastrointestinal stromal tumors. The purpose of this study was to draw the attention of scholars and clinicians to radiotherapy and promote further research on radiotherapy in gastrointestinal stromal tumors.

Abstract

Gastrointestinal stromal tumors (GISTs) are considered insensitive to radiotherapy. However, a growing number of case reports and case series have shown that some lesions treated by radiotherapy achieved an objective response. The aim of the study was to perform a systematic review of all reported cases, case series, and clinical studies of GISTs treated with radiotherapy to reevaluate the role of radiotherapy in GISTs. A systematic search of the English-written literature was conducted using PubMed, Web of Science, and Embase databases. Overall, 41 articles describing 112 patients were retrieved. The included articles were of low to moderate quality. Bone was the most common site treated by radiotherapy, followed by the abdomen. In order to exclude the influence of effective tyrosine kinase inhibitors (TKIs), a subgroup analysis was conducted on whether and which TKIs were concurrently applied with radiotherapy. Results showed that radiotherapy alone or combined with resistant TKIs could help achieve objective response in selected patients with advanced or metastatic GISTs; however, survival benefits were not observed in the included studies. Pain was the most common symptom in symptomatic GISTs, followed by neurological dysfunction and bleeding. The symptom palliation rate was 78.6% after excluding the influence of effective TKIs. The adverse reactions were mainly graded 1–2. Radiotherapy was generally well-tolerated. Overall, radiotherapy may relieve symptoms for GIST patients with advanced or metastatic lesions and even help achieve objective response in selected patients without significantly reducing the quality of life. In addition to bone metastases, fixed abdominal lesions may be treated by radiotherapy. Publication bias and insufficient quality of included studies were the main limitations in this review. Further clinical studies are needed and justified.