Seminoma

Seminoma
Other names	Pure seminoma, classical seminoma
Histopathology of classical seminoma, with typical features.[1]
Specialty	Urology, oncology

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.^[3]

Testicular seminoma originates in the germinal epithelium of the seminiferous tubules.^[4] About half of germ cell tumors of the testicles are seminomas.^[5] Treatment usually requires removal of one testicle. However, fertility usually isn't affected. All other sexual functions will remain intact.

Signs and symptoms

The average age of diagnosis is between 35 and 50 years. This is about 5 to 10 years older than men with other germ cell tumors of the testes. In most cases, they produce masses that are readily felt on

Some cases of seminoma can present as a primary tumour outside the testis, most commonly in the mediastinum.^[6] In the ovary, the tumor is called a dysgerminoma, and in non-gonadal sites, particularly the central nervous system, it is called a germinoma.^[5]

Diagnosis

• 
  Gross pathology of seminoma
• 
  Histopathological image of metastatic seminoma in the inguinal lymph node. Hematoxylin & eosin stain.
• 
  Histopathological image of metastatic seminoma in the inguinal lymph node. At higher magnification. Hematoxylin & eosin stain.
• 
  Micrograph (high magnification) of a seminoma. H&E stain.
• 
  Testicular seminoma, showing a typically prominent

  stroma

  separating the clusters of tumor cells.
• 
  Orchidectomy

  specimen showing seminoma
• 
  The germ cell markers

  CD117 (positive immunohistochemistry pictured) are useful for diagnosis.^[10]

The preferred treatment for most forms of stage 1 seminoma is active surveillance. Stage 1 seminoma is characterized by the absence of clinical evidence of metastasis. Active surveillance consists of periodic history and physical examinations, tumor marker analysis, and radiographic imaging. Around 85-95% of these cases will require no further treatment. Modern radiotherapy techniques as well as one or two cycles of single-agent carboplatin have been shown to reduce the risk of relapse, but carry the potential of causing delayed side effects. Regardless of treatment strategy, stage 1 seminoma has nearly a 100% cure rate.^[13]

Stage 2 seminoma is indicated by the presence of retroperitoneal metastasis. Cases require radiotherapy or, in advanced cases, combination chemotherapy. Large residual masses found after chemotherapy may require surgical resection. Second-line treatment is the same as for nonseminomas.^[12]

Stage 3 seminoma is characterized by the presence of metastasis outside the retroperitoneum—the lungs in "good risk" cases or elsewhere in "intermediate risk" cases. This is treated with combination chemotherapy. Second-line treatment follows nonseminoma protocols.^[12]

References