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

Tumors can rarely overexpress human chorionic gonadotropin (hCG) resulting in false-positive pregnancy tests. Here, we report a 44-year-old female with a metastatic gastrointestinal stromal tumor (GIST) who presented with a positive urine pregnancy test before radiotherapy. Further workup ruled out pregnancy. Following radiotherapy, her metastatic disease progressed and her hCG level continued to rise. To the best of our knowledge, this is the first report of a GIST tumor overexpressing hCG.

[1]  M. Elston,et al.  Factitious Graves' Disease Due to Biotin Immunoassay Interference-A Case and Review of the Literature. , 2016, The Journal of clinical endocrinology and metabolism.

[2]  L. Sullivan,et al.  Significant Immunohistochemical Expression of Human Chorionic Gonadotropin in High-Grade Osteosarcoma is Rare, but May Be Associated with Clinically Elevated Serum Levels , 2014, Pediatric and developmental pathology : the official journal of the Society for Pediatric Pathology and the Paediatric Pathology Society.

[3]  L. Sullivan,et al.  Ectopic production of β-hCG by osteosarcoma: a case report and review of the literature. , 2014, Journal of pediatric hematology/oncology.

[4]  S. Crabb,et al.  Serum total hCGβ level is an independent prognostic factor in transitional cell carcinoma of the urothelial tract , 2014, British Journal of Cancer.

[5]  D. de Jong,et al.  Serum β-HCG and CA-125 as Tumor Markers in a Patient with Osteosarcoma: Case Report , 2011, Tumori.

[6]  Emily S. Reisenbichler,et al.  Βeta‐Human Chorionic Gonadotropin Production Associated with Phyllodes Tumor of the Breast: An Unusual Paraneoplastic Phenomenon 1 , 2009, The breast journal.

[7]  J. Warchoł,et al.  Reduction of human chorionic gonadotropin beta subunit expression by modified U1 snRNA caused apoptosis in cervical cancer cells , 2008, Molecular Cancer.

[8]  C. Kang,et al.  The immunoexpressions and prognostic significance of inhibin alpha and beta human chorionic gonadotrophins (HCG) in breast carcinomas. , 2005, Cancer research and treatment : official journal of Korean Cancer Association.

[9]  Caj Haglund,et al.  Serum HCGβ and CA 72-4 Are Stronger Prognostic Factors than CEA, CA 19-9 and CA 242 in Pancreatic Cancer , 2004, Oncology.

[10]  C. Haglund,et al.  Serum HCGβ, CA 72‐4 and CEA are independent prognostic factors in colorectal cancer , 2002, International journal of cancer.

[11]  Robert H Lyles,et al.  Extragastrointestinal (Soft Tissue) Stromal Tumors: An Analysis of 48 Cases with Emphasis on Histologic Predictors of Outcome , 2000, Modern Pathology.

[12]  S. Mathieu,et al.  The increase in bladder carcinoma cell population induced by the free beta subunit of human chorionic gonadotrophin is a result of an anti-apoptosis effect and not cell proliferation , 2000, British Journal of Cancer.

[13]  J. Slodkowska,et al.  Frequency and Clinical Significance of β-Subunit Human Chorionic Gonadotropin Expression in Non-Small Cell Lung Cancer Patients , 1999, Tumor Biology.

[14]  M. Grossmann,et al.  Measurement of human chorionic gonadotropin‐related immunoreactivity in serum, ascites and tumour cysts of patients with gynaecologic malignancies , 1995, European journal of clinical investigation.

[15]  P. Neven,et al.  Measurement of urinary beta core fragment of human chorionic gonadotrophin in women with vulvovaginal malignancy and its prognostic significance. , 1995, British Journal of Cancer.

[16]  C. Springer,et al.  A cytotoxic agent can be generated selectively at cancer sites. , 1988, British Journal of Cancer.

[17]  U. Stenman,et al.  Choriogonadotropin and its beta subunit separated by hydrophobic-interaction chromatography and quantified in serum during pregnancy by time-resolved immunofluorometric assays. , 1988, Clinical chemistry.

[18]  L. Kahn,et al.  Osteogenic sarcoma producing human chorionic gonadotrophin: Case report with immunohistochemical studies , 1984, Cancer.

[19]  J. Lasota,et al.  Gastrointestinal stromal tumors – definition, clinical, histological, immunohistochemical, and molecular genetic features and differential diagnosis , 2000, Virchows Archiv.