A prospective study of ovarian sex cord–stromal tumours in children and adolescents began enrolling participants in 2005.

Sertoli cell tumors are known to occur in other species, including domestic ducks, dogs, and horses.

The exact cause of Sertoli-Leydig Cell Tumor is not known.

Research studies seem to indicate that certain genetic mutations (in the DICER1 gene) may play a role in many cases.

Sertoli–Leydig cell tumour is a group of tumours composed of variable proportions of Sertoli cells, Leydig cells, and in the case of intermediate and poorly differentiated neoplasms, primitive gonadal stroma and sometimes heterologous elements.

Sertoli–Leydig cell tumour is a member of the sex cord-stromal tumour group of ovarian and testicular cancers. The tumour is rare, comprising less than 1% of testicular tumours. While the tumour can occur at any age, it occurs most often in young adults. Recent studies have shown that many cases of Sertoli–Leydig cell tumor of the ovary are caused by germline mutations in the "DICER1" gene. These hereditary cases tend to be younger, often have a multinodular thyroid goiter and there may be a personal or family history of other rare tumors such as pleuropulmonary blastoma, Wilms tumor and cervical rhabdomyosarcoma.

Closely related terms include arrhenoblastoma and androblastoma. Both terms are classified under Sertoli–Leydig cell tumour in MeSH.

A Sertoli cell nodule, also Pick's adenoma, testicular tubular adenoma and tubular adenoma of the testis, is a benign proliferation of Sertoli cells that arises in association with cryptorchidism (undescended testis). They are not composed of a clonal cell population, i.e. neoplastic; thus, technically, they should not be called an "adenoma".

A retrospective study of 83 women with sex cord–stromal tumours (73 with granulosa cell tumour and 10 with Sertoli-Leydig cell tumour), all diagnosed between 1975 and 2003, reported that survival was higher with age under 50, smaller tumour size, and absence of residual disease. The study found no effect of chemotherapy. A retrospective study of 67 children and adolescents reported some benefit of cisplatin-based chemotherapy.

A Sertoli cell tumour, also Sertoli cell tumor (US spelling), is a sex cord-gonadal stromal tumor of a Sertoli cells. They are very rare and generally peak between the ages of 35 and 50. They are typically well-differentiated, and are commonly misdiagnosed as seminomas as they often appear very similar.

A tumor that produces both Sertoli cells and Leydig cells is known as a Sertoli-Leydig cell tumor.

A recommend surveillance program for Multiple Endocrine Neoplasia Type 1 has been suggested by the International Guidelines for Diagnosis and Therapy of MEN syndromes group.

Multiple Endocrine Neoplasia type 1 (MEN1) is a rare hereditary endocrine cancer syndrome characterized primarily by tumors of the parathyroid glands (95% of cases), endocrine gastroenteropancreatic (GEP) tract (30-80% of cases), and anterior pituitary (15-90% of cases). Other endocrine and non-endocrine neoplasms including adrenocortical and thyroid tumors, visceral and cutaneous lipomas, meningiomas, facial angiofibromas and collagenomas, and thymic, gastric, and bronchial carcinoids also occur. The phenotype of MEN1 is broad, and over 20 different combinations of endocrine and non-endocrine manifestations have been described. MEN1 should be suspected in patients with an endocrinopathy of two of the three characteristic affected organs, or with an endocrinopathy of one of these organs plus a first-degree relative affected by MEN1 syndrome.

MEN1 patients usually have a family history of MEN1. Inheritance is autosomal dominant; any affected parent has a 50% chance to transmit the disease to his or her progeny. MEN1 gene mutations can be identified in 70-95% of MEN1 patients.

Many endocrine tumors in MEN1 are benign and cause symptoms by overproduction of hormones or local mass effects, while other MEN1 tumors are associated with an elevated risk for malignancy. About one third of patients affected with MEN1 will die early from an MEN1-related cancer or associated malignancy. Entero-pancreatic gastrinomas and thymic and bronchial carcinoids are the leading cause of morbidity and mortality. Consequently, the average age of death in untreated individuals with MEN1 is significantly lower (55.4 years for men and 46.8 years for women) than that of the general population.

JCT often is described as benign, however one case of metastasis has been reported, so its malignant potential is uncertain. In most cases the tumor is encapsulated.

A mixed tumor is a tumor derived from one cell type that has divergent differentiation.

Examples include pleomorphic adenoma and Mixed Müllerian tumor.

This is a very rare tumor, since only about 1 in 35,000 to 40,000 people have VHL, of whom about 10% have endolymphatic sac tumors. Patients usually present in the 4th to 5th decades without an gender predilection. The tumor involves the endolymphatic sac, a portion of the intraosseous inner ear of the posterior petrous bone.

Leydig cell tumour, also Leydig cell tumor (US spelling), (testicular) interstitial cell tumour and (testicular) interstitial cell tumor (US spelling), is a member of the sex cord-stromal tumour group of ovarian and testicular cancers. It arises from Leydig cells. While the tumour can occur at any age, it occurs most often in young adults.

A Sertoli-Leydig cell tumour is a combination of a Leydig cell tumour and a Sertoli cell tumour from Sertoli cells.

The usual chemotherapy regimen has limited efficacy in tumours of this type, although Imatinib has shown some promise. There is no current role for radiotherapy.

The usual treatment is surgery. The surgery for females usually is a fertility-sparing unilateral salpingo-oophorectomy. For malignant tumours, the surgery may be radical and usually is followed by adjuvant chemotherapy, sometimes by radiation therapy. In all cases, initial treatment is followed by surveillance. Because in many cases Leydig cell tumour does not produce elevated tumour markers, the focus of surveillance is on repeated physical examination and imaging.

In males, a radical inguinal orchiectomy is typically performed. However, testes-sparing surgery can be used to maintain fertility in children and young adults. This approach involves an inguinal or scrotal incision and ultrasound guidance if the tumour is non-palpable. This can be done because the tumour is typically unifocal, not associated with precancerous lesions, and is unlikely to recur.

The prognosis is generally good as the tumour tends to grow slowly and usually is benign: 10% are malignant. For malignant tumours with undifferentiated histology, prognosis is poor.

Embryonal carcinoma is a relatively uncommon type of germ cell tumour that occurs in the ovaries and testes.

While there is a wide age range at clinical presentation (12–85 years), most patients come to clinical attention at 55 years (mean). There is no gender difference.

In the ovary, embryonal carcinoma is quite rare, amounting to approximately three percent of ovarian germ cell tumours. The median age at diagnosis is 15 years. Symptoms and signs are varied, and may include sexual precocity and abnormal (increased, reduced or absent) uterine bleeding.

There may be elevations in serum human chorionic gonadotropin (hCG) and alpha fetoprotein (AFP) levels but it would be in association with other tumors, (e.g. yolk sac tumor) because they themselves do not produce the serum markers. At surgery, there is extension of the tumour beyond the ovary in forty percent of cases. They are generally large, unilateral tumours, with a median diameter of 17 centimetres. Long-term survival has improved following the advent of chemotherapy. The gross and histologic features of this tumour are similar to that seen in the testis.

Most individuals come to clinical attention during the 5th decade, although the age range is broad (20 to 80 years). There is an equal gender distribution.

Parathyroid cancer occurs in midlife at the same rate in men and women.

Conditions that appear to result in an increased risk of parathyroid cancer include multiple endocrine neoplasia type 1, autosomal dominant familial isolated hyperparathyroidism and hyperparathyroidism-jaw tumor syndrome (which also is hereditary). Parathyroid cancer has also been associated with external radiation exposure, but, most reports describe an association between radiation and the more common parathyroid adenoma.

Metanephric adenoma (MA)is a rare, benign tumour of the kidney, that can have a microscopic appearance similar to a nephroblastoma (Wilms tumours), or a papillary renal cell carcinoma.

It should not be confused with the pathologically unrelated, yet similar sounding, "mesonephric adenoma".

This is a very rare neoplasm accounting for approximately 0.0003% of all tumors and about 2.5% of all external ear neoplasms. There is a wide age range at initial presentation, although the mean age is about 50 years of age. Females are affected slightly more often (1.5:1).

Carcinoma ex pleomorphic adenoma, abbreviated ca ex PA, is a type of cancer typically found in the parotid gland. It arises from the benign tumour pleomorphic adenoma.

Its prognosis depends on the stage. Early tumour have essentially a benign behaviour.

Benign tumors of the ovary include ovarian cysts, such as borderline tumor cysts.

Brunelli "et al." stated that genetic analysis of chromosome 7, 17, and Y may facilitate discrimination of MA from papillary renal cell carcinoma in difficult cases. Their study showed that MA lacks the frequent gain of chromosomes 7 and 17 and losses of the Y chromosome that are typical of papillary renal cell neoplasms, suggesting that MA is not related to renal cell carcinoma and papillary adenoma.

Ovarian tumors, or ovarian neoplasms, are tumors arising from the ovary. They can be benign or malignant (ovarian cancer).