My Clinical Notes

• Divided into germ cell and nongerminal (derived from the stroma or sex cord)
• 95% are germ cell tumours
• Most are highly aggressive that are capable of wide disseminated spread
• Most nongerminal tumours are benign but they can produce steroids leading to endocrinologic syndromes

 

Germ cell tumours

 

• Most commonly affect the 15 to 34 year old age group
• Germ cell tumours are;
  • Seminomas
  • Speramatocytic seminomas
  • Embryonal carcinoma
  • Yolk sac tumour
  • Choriocarcinoma
  • Teratoma

 

• In about 60% of patients there is a mixed of two or more histological patterns in the tumour
• Most tumours in this group originate from intratubular germ cell neoplasia (ITGCN)
• ITGCN  progresses to invasive germ cell tumour in 50% of cases over 5 years
• It is encountered with high frequency in the following conditions;
  • Cryptorchidism
  • Prior germ cell tumours
  • Strong family history of germ cell tumour
  • Androgen insensitivity syndrome
  • Gonadal dysgenesis syndrome
• ITGCN is seen adjacent to all adult germ cell tumours with exception of seminomas, epidermoid and dermoid cysts
• It is also rarely seen in paediatric tumours
• It is identified it is treated with low dose radiotherapy which destroys the germ cells but maintains androgen production of the Leydig cells

 

• Neoplastic germ cells may differentiate alone gonadal lines to become a seminoma or it may transform into a totipotential cell which may give rise to a nonseminomatous tumour.
• Such a nonseminomatous tumour may remain undifferentiated to form a embryonal carcinoma
• Or it may differentiate along extraembryonic lines into a yolk sac tumour of choriocarcinoma
• Teratomas result from differentiation of the embryonal carcinoma along the lines of all three germ cell layers

 

• Clinically the most important distinction to make is between seminomas and nonseminomatous tumours

 

Pathogenesis

 

• Predisposing influences in developing germ cell tumours;
  • Cryptorchidism – 10% are associated with undescended testes. The higher the testes are (intra-abdominal vs inguinal) the greater the risk
  • Testicular dysgenesis – highest risk with testicular feminisation. Also Klinefelter syndrome
  • Genetic factors – sibs of affected individuals have a ten times higher risk of developing testicular cancers

 

Seminomas

• Most common germinal cancer tumour – 50%
• Peak occurs in the thirties
• An identical tumour arises in the ovary called dysgerminoma
• Morphology
  • Produce bulky masses sometimes 10 times the size of the normal testes
  • Usually homogenous, grey, lobulated and not associated with haemorrhage or necrosis
  • In more than half of cases the whole testis is replaced
  • Generally the tunica albuginea is not penetrated but extension to the epididymis, spermatic cord or scrotal sac occurs
  • Microscopically the uniform sheets of cells are divided into poorly demarcated lobules
  • The classical seminoma cell is large and round and has a distinct cell membrane, a clear cytoplasm and a large central nucleus with two prominent nucleoli
  • Classically they do not contain AFP or HCG but stain positively for placental alkaline phosphatase
  • In about 15% of seminomas there is also syncytiotrophoblasts – in this case they do produce small amounts of HCG

 

Spermatocytic Seminoma

• Uncommon – 1% of all testicular germ cell neoplasms
• Affected individuals are generally over 65
• It is a slow growing tumour which rarely metastases
• Morphology
  • Larger than seminomas with a pale grey, soft cut surface often with mucoid cysts
  • They consist of a mixed cell population of medium sized, small and giant cells
  • The name come from the fact that in some of the medium sized cells the chromatin is similar to that seen in the meiotic phase of non-neoplastic spermatocytes

 

Embryonal Carcinoma

• Occur mostly in the 20-30 age group
• They are more aggressive than seminomas
• Morphology
  • Smaller than a seminoma and doesn’t generally replace the entire testes
  • It is generally poorly demarcated and associated with foci of haemorrhage or necrosis
  • It can extend through the tunica albuginea into the epididymis or cord
  • Histologically the tumour shows sheets of undifferentiated cells as well as primitive glandular structures
  • The cells are anaplastic with hyperchromatic nuclei

 

 

 

Yolk sac Tumour

• Also called infantile embryonal carcinoma or endodermal sinus tumour
• It is the most common testicular tumour in children below the age of 3 and in this age group it has a very good prognosis
• In adults the pure form is rare instead it is frequently found in combination with embryonal carcinoma
• Morphology
  • Nonencapsulated tumour with a homogenous, yellow, mucinous appearance
  • Microscopically consists of a reticular network of cuboidal or elongated cells which may form papillary structures or cords
  • In 50% of tumours structures resembling endodermal sinuses may be seen (Schiller-Duval bodies) these consist of a mesodermal core with a central capillary and a parietal layer of cells resembling primitive glomeruli
  • Staining with AFP is characteristic

 

Choriocarcinoma

• Highly malignant
• Composed of both cytotrophoblastic and syncytiotrophoblastic cells
• Identical tumours may occur in the ovary or placenta
• Rare – less than 1% of all germ cell tumours
• Can also occur with a mixed pattern
• Morphology
  • Generally small, often causing no testicular enlargement
  • Because they are rapidly growing they may outgrow their blood supply and sometime the primary testicular focus is replaced by a small fibrous scar leaving only widespread metastases
  • Haemorrhage and necrosis are common
  • Syncytiotrophoblasts produce HCG

 

Teratomas

• A group of complex tumours having cellular or organoid components resembling normal derivatives from more than one germ layer
• More common in children than adults (in adults constitute 3% of all germ cell tumours)
• They are often found combined with other histological types
• In children pure forms of teratoma behave relatively benignly
• In the postpubertal male all teratomas are regarded as malignant and capable of metastases regardless of whether the elements are mature or immature
• Morphology
  • Large, heterogeneous, solid, sometimes with cartilaginous and cystic areas
  • Haemorrhage or necrosis generally indicates a mixture with embryonal carcinoma or choriocarcinoma
  • Can contain;
    • Neural tissue
    • Muscle bundles
    • Cartilage
    • Squamous epithelium
    • Structures reminiscent of thyroid gland
    • Bronchial or bronchiolar epithelium
    • Intestinal wall
    • Brain substance
  • The dermoid cysts and epidermoid cysts that are common in the ovary are rare in the testes
  • Rarely within the teratoma there may be malignant transformation in one or more of the derivatives of the germ cell layers and may result in a squamous cell carcinoma or adenocarcinoma.
  • The importance of recognising these non-germ cell malignancies derived from teratomas is that if they spread out of the testes they are resistant to chemotherapy

 

Mixed tumours

• Account for 60% of testicular tumours
• Carry a worse prognosis
• Common combinations include;
  • Teratoma, embryonal carcinoma and yolk sac tumour
  • Seminoma with embryonal carcinoma
  • Embyronal carcinoma and teratoma

 

Clinical features of testicular tumours

• Clinically testicular tumours are segregated into two broad categories; seminomas and nonseminomatous germ cell tumours (NSGCT)
• NSGCT as well as including tumours of a single cell type also includes those of a mixed phenotype
• Determines therapy
• Presentation is generally with a painless mass
• All testicular masses should be considered malignancy until proven otherwise
• As biopsy can result in tumour spillage into the scrotal skin, the standard management of a solid testicular mass is radical orchiectomy based on the presumption of malignancy

 

Mode of spread

• Lymphatic spread is common to all forms of testicular tumour
• Retroperitoneal para-aortic nodes are the first to be involved with further spread occurring to the  mediastinal and subclavian nodes
• Haematogenous spread commonly occurs to the lungs. Liver, brain and bones may also be involved
• Histologically the metastases may differ from the tumour of origin as they are derived from totipotent cells

 

Clinical difference between seminomas and NSGCT

 

Â	Seminoma	NSGCT
Presentation	Remain localised to testis for a long time so present at Stage 1	May not cause any testicular enlargement. Metastases early, presents Stage II or III
Metastases	Generally involves lymph nodes	More likely to metastasise haematologically, lungs are involved early
Therapeutics	Radiosensitive	Radioresistant

 

Three clinical stages of testicular tumours;

• Stage I – confined to testis, epididymis or spermatic cord
• Stage II – distant spread confined to retroperitoneal nodes below the diaphragm
• Stage III – metastases outside the retroperitoneal nodes or above the diaphragm
• Stages II and III are further subdivided into early or advanced

 

Germ cell tumours after secrete polypeptide hormones and detectable enzymes, including;

• a-fetoprotein (AFP) – associated with yolk sac tumour
• Human chorionic gonadotrophin (HCG) – choriocarcinoma tumours
• Placental alkaline phosphatase
• Placental lactogen
• Lactate dehydrogenase (also produced by skeletal and cardiac muscle)
• Elevated levels of these markers are most often seen in nonseminomatous tumours

 

• Seminomas have the best prognosis – 95% of patients with Stage I or II disease can be cured
• Among the nonseminomatous tumours, they all have a similar prognosis so are treated as a group. 90% can be cured with chemotherapy
• Pure choriocarcinoma has the worst prognosis

 

Tumours of the Sex cord/gonadal stroma

 

• Include;
  • Leydig cell tumours derived from the stroma
  • Sertolic cell tumours derived from the sex cord

 

Leydig (Intersitial) cell tumours

• Can produce androgens, oestrogens or corticosteroids
• Occur between 20 and 60
• Most common presenting feature is testicular swelling
• Gynecomastia may present
• In children hormonal abnormalities such as sexual precocity can dominate
• Morphology
  • Form well circumscribed nodules of a characteristic golden brown colour with an homogeneous cut surface
  • Most are benign but 10% metastasise

 

Sertoli cell tumours (Androblastomas)

• May be composed entirely of Sertoli cells or may contain some granulosa cells
• May produce endocrinologic changes by producing oestrogens and testosterones but not usually enough to cause precocious masculinisation or feminisation
• May present with gynecomastia
• Morphology
  • Small, homogenous, white/yellow nodules
  • Form cordlike structures resembling immature seminiferous tubules
  • Mostly benign – 10% metastasise

 

Gonadoblastoma

• Rare tumours containing a mixture of germ cells and gonadal stromal element
• Almost always arising in dysgenetic gonads
• The germ cell component may become malignant giving rise to an invasive seminoma

 

Testicular lymphoma

• Accounts for 5% of testicular neoplasms
• Most common form of testicular neoplasm in men over 60
• In most cases disseminated disease has already occurred by the time of detection of testicular mass
• Histologically it is generally a diffuse large cell lymphoma
• Prognosis is very poor

This entry was posted on Friday, December 21st, 2007 at 4:50 pm and is filed under Male genital tract. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.