Infants with Klinefelter Syndrome present with a Hormonal Surge During the Minipuberty

Description:
In 1942, Klinefelter and colleagues delineated a syndrome in which postpubertal males showed normal external genitalia, gynecomastia and lack of pubertal virilization; small firm testes with tubular hyalinization with a decreased number of Leydig cells; azoospermia; elevated gonadotropin levels; and decreased 17-ketosteroid levels. It was not until 1959 that the 47,XXY chromosome constitution was demonstrated. The incidence of Klinefelter syndrome is 1.2 per 1000 live-born males. Minimal diagnostic criteria are now accepted to be the presence of at least one Y chromosome and two X chromosomes. Variants with three or four X chromosomes are less common. Klinefelter syndrome accounts for perhaps 5–15% of infertility in males, in particular, the group with oligospermia or azoospermia.
Seminoma arising in patients with Klinefelter's syndrome is extremely rare; to our knowledge, only three cases have been reported in the English language literature. We report a case of intrapelvic seminoma in a 39-year-old man with Klinefelter's syndrome. Gross examination revealed that the tumor was a solid and irregular mass measuring 90 mm in diameter. The cut surfaces of this ill-defined tumor were yellow–white with necrotic foci. Histologically, the tumor cells were separated into lobules by branching, fibrous septa containing lymphocytes. In some parts of the tumor, a cord-like arrangement of tumor cells was present. Immunohistochemically, the tumor cells were strongly and diffusely positive for antiplacental alkaline phosphatase antibody along their cytoplasmic membranes, but negative for both chorionic gonadotrophin and α-fetoprotein. Based on these findings, we diagnosed this tumor as a seminoma. The testes when examined were found to be atrophic bilaterally, but with no tumor lesions. Chromosomal analysis yielded a 47XXY karyotype, compatible with Klinefelter's syndrome. These findings indicate a case of primary intrapelvic seminoma in Klinefelter's syndrome. The patient underwent intensive radiation therapy postoperatively, and he demonstrated no evidence of recurrence or metastasis during the 13-month period following surgery.
Klinefelter syndrome is highly underdiagnosed and diagnosis is often delayed. With the introduction of non-invasive prenatal screening, the diagnostic pattern will require an updated description of the clinical and biochemical presentation of infants with Klinefelter syndrome. In the first months of life, the hypothalamic–pituitary–gonadal (HPG)-axis is transiently activated in healthy males during the so-called minipuberty. This period represents a “window of opportunity” for evaluation of the HPG-axis before puberty and without stimulation tests. Infants with Klinefelter syndrome present with a hormonal surge during the minipuberty. However, only a limited number of studies exist, and the results are contradictory. Further studies are needed to clarify whether infants with Klinefelter syndrome present with impaired testosterone production during the minipuberty. The aim of this review is to describe the clinical and biochemical characteristics of the neonate and infant with Klinefelter syndrome with special focus on the minipuberty and to update the clinical recommendations for Klinefelter syndrome during infancy.
With Regards
Ethan
Journal Coordinator
Global Journal of Research and Review