Nonseminomatous Germ Cell Tumors: An Overview

Introduction

The most common solid organ malignancy, in males of ages between 15 and 35 is testicular neoplasms. In the United States 0.5 percent to 0.1 percent per year (usually about 10000 cancers) are diagnosed each year. The survival rate of five-year is excellent. The primary testicular neoplasms are primarily divided into three types,

1. Germ cell tumor.

2. Sexcord-stromal tumors.

3. Extragonadal tumors.

Histologically, germ cell tumors are classified into seminomas and nonseminomas. Among the two, seminomas are the most common germ cell tumor. Whereas nonseminomatous germ cell tumors are also frequently found. Non seminomas germ cell tumor is a type of testicular cancer which metastasis and typically affects the liver, lungs, central nervous system, and bone in that order of frequency.

What is a Nonseminomatous Germ Cell Tumor?

Germ cell tumor is the most common type of testis cancer, which is mainly divided into two types, like seminoma and nonseminomatous germ cell tumors. It is not unusual for both the seminoma and nonseminomatous germ cell tumor to occur at the same rate, and men can have both seminoma and nonseminomatous germ cell tumor (NSGCT) or a combination of both tumors.

Even though there are more differences between the seminoma and NSGCT, the main differences will be how the tumor looks under the microscope. Among all the germ cell tumors, non seminomatous germ cell tumor is the main group.

Even though NSGCTs are of distinct histological entities, in general they have similar radiographic appearance. These are present widely in the body with variable imaging features, pathology, treatment, and prognosis.

What Are the Types of the Nonseminomatous Germ Cell Tumor?

The prognosis and appearance of NSGCT are found to be very different. Usually there are four main types of NSGCT which can appear alone. But they are mostly seen as a mixed NSGCT with presence of more than one type.

1. Embryonal carcinoma.

2. Yolk Sac carcinoma.

3. Choriocarcinoma.

4. Teratoma.

1. Embryonal Carcinoma:

Among the most rapidly growing and potentially aggressive tumor types is present in about 40 percent of tumors. HCG or alpha fetoprotein (AFP) is secreted by embryonal carcinoma.

2. Yolk Sac Carcinoma:

This type of carcinoma is defined as the most common type of tumor present in children. And will have a good response to chemotherapy in childrens and adults. AFP is always secreted by the yolk sac tumors.

3. Choriocarcinoma:

A testis cancer which is a very rare and very aggressive type will be a choriocarcinoma. HCG is commonly secreted by choriocarcinoma.

4. Teratoma:

Teratoma always appears as a mixed NSGCT, and it grows locally. But it is seen in the retroperitoneal lymph nodes. As teratoma is a radiation and chemotherapy resistant and for better results it is treated with surgical removal.

How Can Nonseminomatous Germ Cell Tumor be Diagnosed Through its History?

• By getting a detailed history and performing a thorough physical examination one can easily diagnose the testicular nonseminomatous germ cell tumor.

• The physicians should enquire about the clinical features like anything unusual with their testicles.

• About undescended testes and orchiopexy, it is important to ask about antenatal maternal and neonatal history.

• It is necessary to know the family history of testicular cancer in the father, brothers, and male blood relatives.

• People should do a complete general physical examination to identify any signs of systemic spread.

• Because when a solid and firm intra-testicular mass is seen on physical examination, it is not considered as a testicular tumor unless it is proven.

• Male infertility is seen in the individuals with non-seminomatous germ cell tumors because it is caused due to low sperm counts, reduced sperm motility, and increased abnormal morphology.

• This is seen in 35 percent of patients with NSGCT, because of spermatogenesis abnormalities.

• So for male infertility patients, a careful examination is needed for tests and also need to do screening for possible testicular masses.

• Patients with localized disease the typical presentation is a painless nodule, lump, mass, or swelling in one of the testes.

• A dull scrotal or testicular pain is also present in them.

• Acute testicular pain is experienced by ten percent of the affected individuals.

• Usually trauma is not seen along with the testicular cancer, but individuals seen in the ER (Emergency Room) having scrotal or testicular trauma will result in an examination or imaging of the testes to prove the final diagnosis.

• A careful testicular examination will help detect a firm intratesticular lesion is needed.

What Are the Pathology and Radiographic Features of Nonseminomatous Germ Cell Tumor?

Pathology:

Based on histopathology, non seminomatous germ cell tumors are divided into:

Yolk Sac Tumor: It is a rare type of cancer present in the germ cells (cells that give rise to sperms or eggs).

Choriocarcinoma: It can be a rare type with the worst prognosis.

Embryonic Cell Carcinoma:

• It is also a rare type.

Mixed Germ Cell tumor:

• This is the most common type of NSGCT.

• It constitutes 40 percent of all germ cell tumors.

• The most commonly seen combination includes teratoma and embryonal cell carcinoma.

Teratoma:

• It constitutes about 5 to 10 percent of germ cell tumors.

• It can be either mature and immature.

• Teratoma involves malignant transformation.

Radiographic Features:

Non seminomatous germ cell tumors are more heterogeneous in structure on ultrasound and on T2-weighted MR images showing frequent cystic areas or calcification when compared to seminomas tumors. Tunica invasion is more common in NSGCT and also they tend to be more aggressive in nature. Based on the location the tumor will vary in appearance and have an individualized appearance.

As the non seminomatous germ cell tumors are location dependent, imaging plays an important role in classifying it.

What is the Treatment and Prognosis of Nonseminomatous Germ Cell Tumor?

Treatment and Prognosis:

The non seminomatous germ cell tumor prognosis is different and depends on the biological behavior of the individual tumors.Tumor markers, location of the primary tumor and the metastasis presence will determine the prognosis of this tumor.

Good Prognosis:

These results are produced by making the below conditions true:

Presence of tumor markers:

1. Alpha-fetoprotein < 1000 nanogram per milliliter.2. Beta HCG < 5000 IU/L3. LDH < 1.5 * upper limit of normal.

• Non-mediastinal location of the primary tumor.

• No non pulmonary metastasis.

Patients are first treated chemotherapy (bleomycin, etoposide, and cisplatin - BEP regimen) and then with orchiectomy.

Intermediate Prognosis:

This results are produced by making the below conditions true:

1. Tumor markers.

• Alpha-fetoprotein: 1000-10,000 nanograms per milliliter.

• beta-hCG: 5000-50,000 International units per liter.

• LDH: 1.5-10*upper limit of normal.

2. Non-mediastinal location of the primary tumor.

3. No non pulmonary metastases.

Usually patients are treated with adjuvant surgery and then with chemotherapy cycles.

Poor Prognosis:

This results are produced by making the below conditions true:

1. Tumor markers:

• alpha-fetoprotein:> 10,000 nanogram per milliliter.

• beta-hCG: >50,000 International units per liter.

• LDH: >10*Upper limit of normal.

2. Mediastinal primary tumor.

3. Presence of Nonpulmonary metastasis.

Because of poor prognosis, surgery is included and patients are followed with aggressive chemotherapy.

Conclusion:

Generally non seminomatous germ cell tumors are curable cancers having a survival rate of more than 95 percent. This cancer malignancy can be identified and controlled by giving a proper awareness about the testicular cancer to health care providers and to the general population.

This cancer can be cured and treated earlier by diagnosing it immediately. Usually in most of the cases testes with mass need to be removed. To achieve a proper diagnosis, and the stage of pathology, patients need to undergo multiple radiological investigations. When tumor has spread distantly, the patients will have signs and symptoms like testicular mass, mostly painless, heaviness in the scrotum, vomiting, and nausea.