Keywords: Malignant thymoma; painful gynecomastia; tamoxifen
Gynecomastia is more common in pubertal ages and in older men. Chemotherapy may injure gonadal and hormonal functions and is associated with the development of gynecomastia.
The patient presented with bilateral acute painful gynecomastia. On physical examination, he appeared well, and his vital signs were normal. The lungs were clear, heart sounds were normal, and the abdomen was soft, with no masses or tenderness. The results of a complete blood count and the levels of electrolytes, calcium, creatinine, urea nitrogen, protein, albumin, globulin, and bilirubin were normal. There was no adenopathy, and testicular examination was normal. Abdominal ultrasonography (USG), testicular USG, and magnetic resonance imaging of the sella turcica were normal. Follicle-stimulating hormone (FSH) 26.18 (1.4-18 mIU/ml) and luteinizing hormone (LH) 16.83 (1.5-9.3 mIU/ml) were high. Beta-human chorionic gonadotropin, testosterone, prolactin, dehydroepiandrosterone sulfate, alpha-fetoprotein, insulin-like growth factor 1, thyroid function tests and cortisol level were normal. In view of progression in this patient, ifosfamide was given as second-line chemotherapy. Tamoxifen (TAM) 20 mg daily was started. Twenty days later, TAM resulted in complete regression of gynecomastia and there has been no recurrence in follow-up physical examinations.
Primary hypogonadism due to Leydig cell damage from any cause (e.g., mumps orchitis, trauma, cytotoxic chemotherapy, alkylating agents, vincristine, nitrosoureas, methotrexate) is commonly associated with gynecomastia. First, levels of total and free testosterone decrease. Second, the resulting increase in serum LH stimulates the aromatase enzyme in testicular Leydig cells to produce more estrogen. In addition, peripheral aromatization of the adrenal androgen androstenedione to estrogen remains unaffected.
Preliminary efficacy data from a retrospective
chart review of patients with gynecomastia indicated
that TAM was associated with reductions in
breast size and decreased pain.[
LH and FSH are secreted by adenocarcinoma
and large cell carcinoma. However, to our knowledge,
there is no case in the literature describing
paraneoplastic gynecomastia with malignant thymoma.
It can be speculated that LH and FSH are
secreted in malignant thymoma and that gynecomastia
developed as a paraneoplastic entity.