| Embryonal carcinoma | |
|---|---|
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| Micrograph of an embryonal carcinoma showing its typical features – prominent nucleoli, marked nuclear atypia, necrosis, and nuclear overlap. H&E stain. | |
| Specialty | Urology, gynecology |
Embryonal carcinoma is a relatively uncommon type of nonseminomatous germ cell tumour that occurs in the ovaries and testes.
The presenting features may be a palpable testicular mass or asymmetric testicular enlargement in some cases. The tumour may present as signs and symptoms relating to the presence of widespread metastases, without any palpable lump in the testis. The clinical features associated with metastasising embryonal carcinoma may include low back pain, dyspnoea, cough, haemoptysis, haematemesis and neurologic abnormalities. [1]
Males with pure embryonal carcinoma tend to have a normal amount of the protein alpha-fetoprotein in the fluid component of their blood. The finding of elevated amounts of alpha-fetoprotein is more suggestive of a mixed germ cell tumour, with the alpha-fetoprotein being released by the yolk sac tumour component.[ citation needed ]
The gross examination usually shows a two to three centimetre pale grey, poorly defined tumour with associated haemorrhage and necrosis. [2]
The microscopic features include: indistinct cell borders, mitoses, a variable architecture (tubulopapillary, glandular, solid, embryoid bodies – ball of cells surrounded by empty space on three sides), nuclear overlap, and necrosis.[ citation needed ]
Solid (55%), glandular (17%), and papillary (11%) are the most common primary patterns (predominant architectural pattern occupying at least 50%). Other less common primary patterns included nested (3%), micropapillary (2%), anastomosing glandular (1%), sieve-like glandular (<1%), pseudopapillary (<1%), and blastocyst-like (<1%). [3]
Testicular embryonal carcinoma occurs mostly (84%) as a component of a mixed germ cell tumor, but 16% are pure. Occasionally, embryonal carcinoma develops predominantly in the context of polyembryoma-like (6%) and diffuse embryoma-like ("necklace" pattern) (3%) proliferations. [3]
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. [1]
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. [4] 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. [1] The gross and histologic features of this tumour are similar to that seen in the testis.[ citation needed ]
In the testis pure embryonal carcinoma is also uncommon, and accounts for approximately ten percent of testicular germ cell tumours. However, it is present as a component of almost ninety percent of mixed nonseminomatous germ cell tumours. The average age at diagnosis is 31 years, and typically presents as a testicular lump which may be painful. One-fifth to two-thirds of patients with tumours composed predominantly of embryonal carcinoma have metastases at diagnosis. [1]
An important key to distinguish it from other tumors, such as seminoma (vacuolated), teratocarcinoma (three differentiated germ layers), yolk sac tumor (Schiller–Duval bodies), and the Sertoli–Leydig cell tumor (strings of glands), is that the embryonal carcinoma cells are "trying" to evolve into their next stage of development. So in the testicle, they are often observed as blue cells attempting to form primitive tubules. [5]
Alpha-fetoprotein is a protein that in humans is encoded by the AFP gene. The AFP gene is located on the q arm of chromosome 4 (4q13.3). Maternal AFP serum level is used to screen for Down syndrome, neural tube defects, and other chromosomal abnormalities.
A teratoma is a tumor made up of several different types of tissue, such as hair, muscle, teeth, or bone. Teratomata typically form in the tailbone, ovary, or testicle.
Testicular cancer is cancer that develops in the testicles, a part of the male reproductive system. Symptoms may include a lump in the testicle or swelling or pain in the scrotum. Treatment may result in infertility.
Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different cell types including epithelial cells, germ cells, and stromal cells. When these cells become abnormal, they have the ability to divide and form tumors. These cells can also invade or spread to other parts of the body. When this process begins, there may be no or only vague symptoms. Symptoms become more noticeable as the cancer progresses. These symptoms may include bloating, vaginal bleeding, pelvic pain, abdominal swelling, constipation, and loss of appetite, among others. Common areas to which the cancer may spread include the lining of the abdomen, lymph nodes, lungs, and liver.
Choriocarcinoma is a malignant, trophoblastic cancer, usually of the placenta. It is characterized by early hematogenous spread to the lungs. It belongs to the malignant end of the spectrum in gestational trophoblastic disease (GTD). It is also classified as a germ cell tumor and may arise in the testis or ovary.
Sex cord–gonadal stromal tumour is a group of tumours derived from the stromal component of the ovary and testis, which comprises the granulosa, thecal cells and fibrocytes. In contrast, the epithelial cells originate from the outer epithelial lining surrounding the gonad while the germ cell tumors arise from the precursor cells of the gametes, hence the name germ cell. In humans, this group accounts for 8% of ovarian cancers and under 5% of testicular cancers. Their diagnosis is histological: only a biopsy of the tumour can make an exact diagnosis. They are often suspected of being malignant prior to operation, being solid ovarian tumours that tend to occur most commonly in post menopausal women.
Germ cell tumor (GCT) is a neoplasm derived from the primordial germ cells. Germ-cell tumors can be cancerous or benign. Germ cells normally occur inside the gonads. GCTs that originate outside the gonads may be birth defects resulting from errors during development of the embryo.
A seminoma is a germ cell tumor of the testicle or, more rarely, the mediastinum or other extra-gonadal locations. It is a malignant neoplasm and is one of the most treatable and curable cancers, with a survival rate above 95% if discovered in early stages.
A germinoma is a type of germ-cell tumor, which is not differentiated upon examination. It may be benign or malignant.
Polyembryoma is a rare, very aggressive form of germ cell tumor usually found in the ovaries. Polyembryoma has features of both yolk sac tumour and undifferentiated teratoma/embryonal carcinoma, with a characteristic finding of embryoid bodies lying in a loose mesenchymal stroma.
Spermatocytic tumor, previously called spermatocytic seminoma, is a neoplasm of the testis, and classified as a germ cell tumour.
Germ cell neoplasia in situ (GCNIS) represents the precursor lesion for many types of testicular germ cell tumors.
The WHOclassification of tumours of the central nervous system is a World Health Organization Blue Book that defines, describes and classifies tumours of the central nervous system (CNS).
A Sertoli cell tumour, also Sertoli cell tumor, is a sex cord–gonadal stromal tumour of Sertoli cells. They can occur in the testis or ovary. They are very rare and generally peak between the ages of 35 and 50. They are typically well-differentiated and may be misdiagnosed as seminomas as they often appear very similar.
Leydig cell tumour, also Leydig cell tumor, (testicular) interstitial cell tumour and (testicular) interstitial cell tumor, 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.
Orchiectomy is a surgical procedure in which one or both testicles are removed. The surgery can be performed for various reasons:
Endodermal sinus tumor (EST) is a member of the germ cell tumor group of cancers. It is the most common testicular tumor in children under three, and is also known as infantile embryonal carcinoma. This age group has a very good prognosis. In contrast to the pure form typical of infants, adult endodermal sinus tumors are often found in combination with other kinds of germ cell tumor, particularly teratoma and embryonal carcinoma. While pure teratoma is usually benign, endodermal sinus tumor is malignant.
Scrotalultrasound is a medical ultrasound examination of the scrotum. It is used in the evaluation of testicular pain, and can help identify solid masses.
An extracranial germ cell tumor (EGCT) occurs in the abnormal growth of germ cells in the gonads and the areas other than the brain via tissue, lymphatic system, or circulatory system. The tumor can be benign or malignant (cancerous) by its growth rate. According to the National Cancer Institute and St. Jude Children's Research Hospital, the chance of children who are under 15 years old having EGCTs is 3%, in comparison to adolescents, a possibility of 14% with aged 15 to 19 can have EGCTs. There is no obvious cut point in between children and adolescents. However, common cut points in researches are 11 years old and 15 years old.
Ovarian germ cell tumors (OGCTs) are heterogeneous tumors that are derived from the primitive germ cells of the embryonic gonad, which accounts for about 2.6% of all ovarian malignancies. There are four main types of OGCTs, namely dysgerminomas, yolk sac tumor, teratoma, and choriocarcinoma.