Sertoli cell-only syndrome (SCOS) is an uncommon medical disorder that results in male infertility. It is characterized by the presence of solely Sertoli cells in the seminiferous tubules' lining.
Sertoli cell-only syndrome (SCOS) is a rare testicular condition and is primarily idiopathic or, less frequently, associated with other underlying pathologies. The primary reason due to which men seek medical advice is infertility; additional manifestations may complicate the clinical picture when SCOS is induced by other diseases.
Patients are male, belong to the age group of 20 to 40 and present due to reported infertility. A clinical examination of the testes usually reveals no shape or other irregularities, but a significant atrophy could be present in certain cases. Gynecomastia is not present and all masculine characteristics are found normal. Some patients with Sertoli cell-only syndrome may exhibit varicocele, that is mainly bilateral . The aforementioned clinical picture refers to cases of SCOS that are later diagnosed as idiopathic.
This medical condition, however, can also be secondary to other disorders. Klinefelter syndrome, exposure to toxins or chemicals, radiation therapy, and profound trauma have all been associated with SCOS. Symptoms related to the underlying pathology are therefore present in an occasion of secondary SCOS. More specifically, amongst the karyotype defects linked to the syndrome, Klinefelter syndrome has been documented as the most common genetic abnormality ; these patients exhibit a variety of manifestations complementary to infertility, including speech defects, sexual dysfunction, long arms and legs, reduced facial, body, and pubic hair, tremor, and cardiovascular problems   . A physical examination of patients with Sertoli cell-only syndrome developing as a result of Klinefelter syndrome is also expected to reveal hypospadias, epispadias, or micropenis. Gynecomastia may be frequently seen in these cases.
Lastly, a single literary report has documented a patient with SCOS who was diagnosed with insulinoma . A confirmed association between these two medical entities has, however, yet to be established.
Patients who seek medical advice due to infertility are subjected to a series of blood and semen laboratory examinations, in order to detect the specific cause. In order for Sertoli cell-only syndrome to be accurately diagnosed, the following laboratory tests are required:
- Hormonal studies: follicle-stimulating hormone (FSH) and testosterone levels are a vital parameter. Patients affected by SCOS are usually found to have increased levels of FSH (>3 times the reference range value) with a normal testosterone count . Anti-Mullerian hormone (AMH) concentration is usually decreased, as is serum inhibin B.
- Semen analysis: azoospermia. Rarely, spermatogenetic foci may be illustrated in an SCOS testis.
Karyotyping, luteinizing hormone (LH) levels, and prolactin levels are not ordered as routine tests in a possible SCOS case. However, the karyotype of the male patients is expected to be normal, but microdeletions on the Y chromosome are possible.
The decisive diagnosis of Sertoli cell-only syndrome is made via a testicular biopsy, that will reveal the complete germ cell absence and the seminiferous tubules that are exclusively lined by Sertoli cells.
- Gat Y, Gornish M, Perlow A, et al. Azoospermia and Sertoli-cell-only syndrome: hypoxia in the sperm production site due to impairment in venous drainage of male reproductive system. Andrologia. 2010;42(5):314-321.
- Stouffs K, Gheldof A, Tournaye H, et al. Sertoli Cell-Only Syndrome: Behind the Genetic Scenes. BioMed Research International Volume 2016 (2016), ID 6191307.
- Robinson A, Bender BG, Linden MG, Salbenblatt JA. Sex chromosome aneuploidy: the Denver Prospective Study. Birth Defects Orig Artic Ser. 1990;26(4):59-115.
- Visootsak J, Aylstock M, Graham JM Jr. Klinefelter syndrome and its variants: an update and review for the primary pediatrician. Clin Pediatr (Phila). 2001;40(12):639-651.
- Völkl TM, Langer T, Aigner T, et al. Klinefelter syndrome and mediastinal germ cell tumors. Am J Med Genet A. 2006;140(5):471-481.
- Malabu U, Gowda D, Tan YM. Insulinoma Presenting with Long-Standing Depression, Primary Hypogonadism, and Sertoli Cell Only Syndrome. Case Rep Endocrinol. 2013; 2013: 926385.
- Hanmayyagari B, Guntaka M, Srinagesh. A rare case of male infertility: Sertoli only syndrome. CHRISMED Journal of Health and Research. 2015;2:64-67.