Spermatocytic seminoma
Encyclopedia
Spermatocytic seminoma is a neoplasm of the testis (i.e. a tumour of the testis), and classified as a germ cell tumour.
The name of the tumour comes from the similarity (under the microscope
) between the small cells of the tumour and secondary spermatocytes.
. It has not been described as arising in locations outside the testis, and does not occur in association with other germ cell tumours.
on medical imaging
.
The macroscopic
appearance of the tumour is of a mutinodular grey-white to tan coloured mass with gelatinous, haemorrhagic and necrotic
areas. The tumour may extend beyond the testis.
populations:
The cells are generally packed into nodules, and have a loose, sheet-like arrangement that is commonly interrupted by interstitial oedema. Unlike classical seminoma, fibrous septation and lymphocytic
infiltrates are not seen. Cells undergoing mitosis
are common, as are cells undergoing apoptosis
.
Intratubular growth of spermatocytic seminoma can be seen, however there is no intratubular germ cell neoplasia
of unspecified type (IGCNU). The intratubular growth probably accounts for the appearance of separate tumour nodules within the testis.
Immunostaining
for most of the usual testicular germ cell tumour markers is negative (i.e. placental alkaline phosphatase (PLAP), vimentin
, actin
, desmin
, alpha fetoprotein (AFP), OCT4, human chorionic gonadotropin
(hCG), and carcinoembryonic antigen
(CEA)).
Rarely, spermatocytic seminomas may show sarcoma
toid differentiation, most commonly as undifferentiated spindled cells intermingled within the typical-appearing spermatocytic seminoma cells. Rhabdomyosarcoma
tous differention has also been described.
e, so radical orchidectomy alone is sufficient treatment, and retroperitoneal lymph node dissection and adjuvant chemotherapy or radiotherapy are generally not required.
The name of the tumour comes from the similarity (under the microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
) between the small cells of the tumour and secondary spermatocytes.
Relation to seminoma
Spermatocytic seminoma is not considered a subtype of seminoma and, unlike seminoma and most other germ cell tumours, it does not arise from intratubular germ cell neoplasiaIntratubular germ cell neoplasia
Intratubular germ cell neoplasia, abbreviated ITGCN or IGCN and also known as testicular intratubular germ cell neoplasia and intratubular germ cell neoplasia of the testis, is considered a precursor lesion for many types of testicular germ cell tumors.The common, unspecified variant of the entity...
. It has not been described as arising in locations outside the testis, and does not occur in association with other germ cell tumours.
Presentation
Spermatocytic seminoma is a rare tumour, comprising only one to two percent of all testicular germ cell tumours. Men presenting with this tumour are generally 50 to 60 years old, and its occurrence is rare in men under 30 years old. Most present with slow, painless testicular enlargement, which may involve both testes.Diagnosis
Spermatocytic seminomas are diagnosed based on tissue from orchiectomy (or partial orchiectomy), done for a lesion suspicious for cancerCancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
on medical imaging
Medical imaging
Medical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...
.
The macroscopic
Macroscopic
The macroscopic scale is the length scale on which objects or processes are of a size which is measurable and observable by the naked eye.When applied to phenomena and abstract objects, the macroscopic scale describes existence in the world as we perceive it, often in contrast to experiences or...
appearance of the tumour is of a mutinodular grey-white to tan coloured mass with gelatinous, haemorrhagic and necrotic
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
areas. The tumour may extend beyond the testis.
Histologic appearance
Histologically, spermatocytic seminomas consist of three cellCell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
populations:
- small cells with a large nuclearCell nucleusIn cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
-to-cytoplasmCytoplasmThe cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...
ic ratioRatioIn mathematics, a ratio is a relationship between two numbers of the same kind , usually expressed as "a to b" or a:b, sometimes expressed arithmetically as a dimensionless quotient of the two which explicitly indicates how many times the first number contains the second In mathematics, a ratio is...
(6-8 µm), - medium sized cells with prominent nucleoli (15-18 µm) and,
- large cells (50-100 µm).
The cells are generally packed into nodules, and have a loose, sheet-like arrangement that is commonly interrupted by interstitial oedema. Unlike classical seminoma, fibrous septation and lymphocytic
Lymphocyte
A lymphocyte is a type of white blood cell in the vertebrate immune system.Under the microscope, lymphocytes can be divided into large lymphocytes and small lymphocytes. Large granular lymphocytes include natural killer cells...
infiltrates are not seen. Cells undergoing mitosis
Mitosis
Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two cells containing roughly...
are common, as are cells undergoing apoptosis
Apoptosis
Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...
.
Intratubular growth of spermatocytic seminoma can be seen, however there is no intratubular germ cell neoplasia
Intratubular germ cell neoplasia
Intratubular germ cell neoplasia, abbreviated ITGCN or IGCN and also known as testicular intratubular germ cell neoplasia and intratubular germ cell neoplasia of the testis, is considered a precursor lesion for many types of testicular germ cell tumors.The common, unspecified variant of the entity...
of unspecified type (IGCNU). The intratubular growth probably accounts for the appearance of separate tumour nodules within the testis.
Immunostaining
Immunostaining
Immunostaining is a general term in biochemistry that applies to any use of an antibody-based method to detect a specific protein in a sample. The term immunostaining was originally used to refer to the immunohistochemical staining of tissue sections, as first described by Albert Coons in 1941...
for most of the usual testicular germ cell tumour markers is negative (i.e. placental alkaline phosphatase (PLAP), vimentin
Vimentin
Vimentin is a type III intermediate filament protein that is expressed in mesenchymal cells. IF proteins are found in all metazoan cells as well as bacteria. IF, along with tubulin-based microtubules and actin-based microfilaments, comprise the cytoskeleton...
, actin
Actin
Actin is a globular, roughly 42-kDa moonlighting protein found in all eukaryotic cells where it may be present at concentrations of over 100 μM. It is also one of the most highly-conserved proteins, differing by no more than 20% in species as diverse as algae and humans...
, desmin
Desmin
Desmin is a protein that in humans is encoded by the DES gene.Desmin is a type III intermediate filament found near the Z line in sarcomeres. It was first described in 1976, first purified in 1977, the gene was cloned in 1989, and the first knock-out mouse was created in 1996. Desmin is only...
, alpha fetoprotein (AFP), OCT4, human chorionic gonadotropin
Human chorionic gonadotropin
Human chorionic gonadotropin or human chorionic gonadotrophin is a glycoprotein hormone produced during pregnancy that is made by the developing embryo after conception and later by the syncytiotrophoblast .. Some tumors make this hormone; measured elevated levels when the patient is not...
(hCG), and carcinoembryonic antigen
Carcinoembryonic antigen
Carcinoembryonic antigen is a glycoprotein involved in cell adhesion. It is normally produced during fetal development, but the production of CEA stops before birth. Therefore, it is not usually present in the blood of healthy adults, although levels are raised in heavy smokers...
(CEA)).
Rarely, spermatocytic seminomas may show sarcoma
Sarcoma
A sarcoma is a cancer that arises from transformed cells in one of a number of tissues that develop from embryonic mesoderm. Thus, sarcomas include tumors of bone, cartilage, fat, muscle, vascular, and hematopoietic tissues...
toid differentiation, most commonly as undifferentiated spindled cells intermingled within the typical-appearing spermatocytic seminoma cells. Rhabdomyosarcoma
Rhabdomyosarcoma
A rhabdomyosarcoma is a type of cancer, specifically a sarcoma , in which the cancer cells are thought to arise from skeletal muscle progenitors. It can also be found attached to muscle tissue, wrapped around intestines, or in any anatomic location...
tous differention has also been described.
Treatment
Unlike classical seminoma, spermatocytic seminomas rarely metastasisMetastasis
Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
e, so radical orchidectomy alone is sufficient treatment, and retroperitoneal lymph node dissection and adjuvant chemotherapy or radiotherapy are generally not required.
External links
- Spermatocytic seminoma micrograph - webpathology.com.