Concurrent Male Gynecomastia and Testicular Hydrocele after Imatinib Mesylate Treatment of a Gastrointestinal Stromal Tumor

Abstract

We report a gastrointestinal stromal tumor (GIST) patient with male gynecomastia and testicular hydrocele after treatment with imatinib mesylate. A 42 yr-old male patient presented for management of hepatic masses. Two years earlier, he had undergone a small bowel resection to remove an intraabdominal mass later shown to be a GIST, followed by adjuvant radiation therapy. At presentation, CT scan revealed multiple hepatic masses, which were compatible with metastatic GIST, and he was prescribed imatinib 400 mg/day. During treatment, he experienced painful enlargement of the left breast and scrotal swelling. Three months after cessation of imatinib treatment, the tumors recurred, and, upon recommencing imatinib, he experienced painful enlargement of the right breast and scrotal swelling. He was diagnosed with male gynecomastia caused by decreased testosterone and non-communicative testicular hydrocele. He was given androgen support and a hydrocelectomy, which improved his gynecomastia. The mechanism by which imatinib induces gynecomastia and hydrocele is thought to be associated with an inhibition of c-KIT and platelet-derive growth factor. This is the first report, to our knowledge, describing concurrent male gynecomastia and testicular hydrocele after imatinib treatment of a patient with GIST.

Bilateral masculine mastoplasia associated with imatinib mesylate: A case report and literature review

“…Imatinib can reduce the testosterone biosynthesis by blocking the c-kit and PDGFR expression in testis [8] . The reduction of free testosterone level had been detected in the 9 patients with Imatinib-induced gynecomastia [3,4] , in which the complementary increase in luteinising hormone may have stimulated the development of breast glandular tissues. The patient in our study obtained satisfactory recovery when the imatinib dosage was decreased, so his adverse effects may be associated with high dosage levels.…”

“…Only about 5 percent of cases are severe or life-threatening. Bilateral masculine mastoplasia is a rare phenomenon, with only 9 reported cases (8 cases of CML [3] , 1 case of GIST [4] ), all of which occurred outside of China. We have not found any case reports associated with such a rare drug-induced side effect in China, so it is necessary and valuable to report this case in order to bring awareness to other clinicians and allow patients the most appropriate treatment.…”

“…Imatinib functions as an oral anti-oncologic medicine by inhibiting not only the bcr-abl tyrosine kinase, but also the c-kit tyrosine kinase and platelet-derived growth factor receptor (PDGFR) tyrosine kinase. Due to its inhibition on c-kit and PDGFR, imatinib is considered to be responsible for certain side effects, including gynecomastia [4] . Imatinib can reduce the testosterone biosynthesis by blocking the c-kit and PDGFR expression in testis [8] .…”

Gynecomastia in a male after dasatinib treatment for chronic myeloid leukemia

“…5 By inhibiting c-kit and PDGFR, imatinib is likely to reduce the cytoplasmatic availability of Cyp 17 and testosterone production. 6 Reduced Figure 1 Bilateral gynecomastia, with enlargement of soft and elastic tissue concentric to the nipple area, 2 months after dasatinib treatment Letters to the Editor levels of testosterone seem to be responsible for gynecomastia. Dasatinib is also a potent inhibitor of Src kinases.…”

“…3,4 The authors of two recent reports document several cases of gynecomastia in male patients treated with imatinib for CML or gastrointestinal stromal tumor and hypothesize a mechanism by which the drug reduces testosterone production through the block of PDGFR and c-kit in the testis. 5,6 We describe gynecomastia and its management in a male patient after treatment with dasatinib for CML.…”