Long-term adjuvant imatinib treatment for a patient who underwent complete resection of a localized recurrent gastrointestinal stromal tumor after preoperative imatinib treatment: A case report

Ultrasensitive detection of imatinib in human serum using a gold-based paper sensor

Imatinib is the tyrosine kinase inhibitor of choice for the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors. However, imatinib has drawbacks such as drug resistance and significant differences in pharmacokinetics within patients. Therefore, a colloidal gold-based immunochromatographic assay (CG-IA) was developed for measuring and monitoring imatinib in human serum. An imatinib derivative containing carboxyl groups was used for the synthesis of the immunogen, and 4-(4-methyl-1-piperazinylmethyl) benzoic acid was selected as the hapten for the heterologous coating antigen. Next, a highly sensitive and specific monoclonal antibody (mAb), 2F7 was screened for the construction of a CG-IA, with an IC50 value of 0.091 ng/mL. For the qualification of imatinib in human serum, the visual limit of detection (vLOD) and cut-off values of the CG-IA were 2 and 20 ng/mL, respectively. For quantitative detection, the calculated LOD value of the CG-IA was 0.068 ng/mL, with a linearity range of 1.004 and 23.087 ng/mL. The recovery rate of spiked serum samples was between 88.24 % and 104.75 %. In addition, the concentration of imatinib in the serum samples from 10 patients was detected by CG-IA and revealed a good correlation with those from LC-MS/MS. These results indicated that the developed gold-based paper sensor could become an effective tool for the rapid monitoring of imatinib in human serum samples.

Rectovaginal extragastrointestinal stromal tumour (EGIST): an additional entity to be considered in the differential diagnosis of tumours of the rectovaginal septum

Gastrointestinal stromal tumours (GISTs) are rare - and rectovaginal extragastrointestinal stromal tumours (RV-EGISTs) even rarer. We share a case of RV-EGIST, complemented by high-quality radiological and surgical images. A review of current literature pertaining to RV-EGIST is also included. Our case report highlights the diagnostic challenge presented by extragastrointestinal stromal tumours. Differentiated from overlapping pathologies only by targeted application of immunohistopathology and cytogenetics, the inclusion of RV-EGIST in the differential diagnosis of a rectovaginal tumour is essential to making this correct diagnosis. Primary surgery is the treatment of choice for RV-EGIST if complete cytoreduction can be achieved, combined with adjuvant tyrosine kinase inhibitor (TKI) therapy for those with high-risk features to further reduce rates of future recurrence.

Gastrointestinal stromal tumor presenting as a rectovaginal septal mass: A case report and review of literature

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) arising from the gynecological tract are extremely rare. A case of GIST with an unusual presentation as a vaginal mass is presented with comprehensive literature review, aiming to gain a better understanding of the diagnostic and treatment strategy of the disease.

PATIENT CONCERNS

A 78-year-old woman presented with persistent vaginal bleeding and difficulty in micturition. Although the tumor mass was diagnosed, the results of preoperative evaluations are uncertain.

DIAGNOSIS

Preoperative evaluation included the computed tomography examination (a 6.3×5.3 cm cervical mass lesion with rectal and vaginal invasion), colonoscopy (an external compression with an intact mucosa), tumor markers, and biopsy (spindle cell tumor). Postoperative histopathology confirmed the diagnosis of GIST.

INTERVENTIONS

Posterior exenteration with complete resection was performed. The patient received postoperative adjuvant imatinib therapy.

OUTCOMES

The patient has survived without the disease for more than 3 years.

CONCLUSION

It is still a challenge to diagnose GISTs in women with rectovaginal mass preoperatively. Efforts should be made, including a high suspicion and an assistance of immunohistochemistry. A precise diagnosis may offer a better surgical and treatment plan, especially on the preservation of reproductive organs and accessibility of targeted therapy.