Keywords
Intestinal - metastasis - renal - seminoma - testis
Introduction
Visceral metastases of seminoma at presentation can be seen in <5% of patients and
in general occur late in the course of the disease. Seminoma can rarely metastasize
to the kidney and metastasize to the gastrointestinal tract (GIT) is least likely
with an incidence of <1%.[1] We report a rare case of metastatic seminoma in a 40-year-old male who presented
with renal and intestinal mass 2 years after orchidectomy for seminoma.
Case Report
A 40-year-male was admitted with chief complaints of swelling in the left flank and
abdominal discomfort for 2 years. The swelling was gradually increasing in size and
was not associated with fever, hematuria, or constipation. The patient was a chronic
smoker. Hematological and biochemical investigations were within normal limits. X-ray
chest was normal. Ultrasonography abdomen suggested a left renal mass with tumor emboli
in the left renal vein and inferior vena cava lumen. Computed tomography abdomen was
done and showed left renal mass at the lower pole with complete encasement of ipsilateral
ureter, renal artery, and vein. Tumor was extending medially up to the aorta with
mild paravertebral extension at L2 into the para-aortic lymph nodes and infiltration
of the psoas muscle and colon [Figure 1]. Fine needle aspiration cytology was done from outside which showed single and small
groups of atypical cells with eccentric hyperchromatic nuclei and focally appreciable
vacuolated cytoplasm against a hemorrhagic background. Cytological diagnosis was malignant
tumor with a possibility of clear cell renal carcinoma.
Figure 1: (a) Magnetic resonance imaging showing a large relatively well-defined irregular
shape, heterogeneously enhancing mass lesion with delayed filling seen in the perinephric
and renal capsular region at the lower pole of the left kidney. (b) Mass is causing
complete encasement of renal artery and vein
The patient underwent nephrectomy, adherent segmental colectomy along with left ureteric
and para-aortic lymph node excision.
Histopathological Examination
Histopathological Examination
The kidney measured 8.5 cm × 5 cm × 3 cm with adherent 9.5 cm of the colon. External
surface of the kidney appeared gray-white and encapsulated except for the area where
the segment of the intestine was adherent. Serial slicing revealed a poorly circumscribed
firm white nodular lesion toward the lateral surface. Pelvicalyceal system was dilated
with a clot in the hilar area. Two para-aortic lymph nodes were also identified measuring
3 cm × 2 cm × 1 cm and 2 cm × 1 cm × 1 cm. The tumor was infiltrating into the adherent
large intestine.
On microscopy, multiple sections from the renal mass showed prominent fibrohistiocytic
proliferation [Figure 2a], confluent epithelioid cell granulomas, lymphocytic infiltrate, and giant cells.
Intervening areas and the pelvis were infiltrated by single as well as nests of tumor
cells. The cells were showed moderate nuclear pleomorphism, vesicular chromatin, prominent
nucleoli, and scant-to-moderate amount of clear cytoplasm [Figure 2b]. Large areas of necrosis were also noted. The tumor was infiltrating the renal capsule.
Ten para-aortic lymph nodes were identified, out of which five showed tumor deposits;
however, the ureter was free of tumor. Multiple sections from the large intestine
showed infiltration by the tumor [Figure 2c].
Figure 2: (a) Nests of tumor cells with intervening fibroblastic and histiocytic proliferation
and infiltration by lymphocytes (H and E, ×100), (b) tumor cells showing moderate
nuclear pleomorphism, vesicular chromatin, prominent nucleoli, and scant-to-moderate
amount of cytoplasm with cytoplasmic clearance (H and E, ×400), (c) photomicrograph
showing metastasis to the intestine (H and E, ×40), (d) CD117-positive tumor cells
(IHC, ×400
Considering the morphological features, differential diagnosis of clear cell renal
carcinoma, lymphoma, and metastatic seminoma was kept, and immunohistochemical (IHC)
panel was applied [Table 1]. Based on the histomorphology and IHC IHC [Figure 2a], [b], [c], [d], a diagnosis of metastatic seminoma with florid granulomatous reaction in the kidney,
colon, and para-aortic lymph nodes was made.
Table 1
List of Immunohistochemistry panel and results
|
IHC marker
|
Result
|
|
Pancytokeratin
|
Focal positive
|
|
EMA
|
Negative
|
|
Vimentin
|
Negative
|
|
CD10
|
Negative
|
|
CD117
|
Positive
|
|
S100
|
Negative
|
|
LCA
|
Negative
|
|
PLAP
|
Negative
|
|
CK 7
|
Negative
|
The patient was then interrogated for surgical history which revealed that he had
undergone left orchidectomy with left-sided hernioplasty 2 years back at some other
hospital. Histopathological examination report showed a diagnosis of seminoma of the
left testis with exuberant granulomatous reaction. Spermatic cord also showed infiltration
by the tumor. However, the patient did not receive any therapy after orchidectomy.
Discussion
Seminoma accounts for half of all germ cell tumors, whereas nonseminomatous germ cell
tumors account for the remaining half. Metastatic spread of these tumors typically
occurs via retroperitoneal lymphatics, and the most common sites include retroperitoneal
lymph nodes, lungs, liver, brain, and bone. Extranodal metastasis of pure seminoma
is very uncommon. Metastasis to GIT is even rarer. In a study by Chait et al., which included postmortem data, metastases to the GIT were documented in 25 of
487 (5%) patients with testicular cancer.[2] However, GIT metastasis by pure seminoma was not documented in this series. In a
study by Husband and Bellamy, 20 out of 650 patients (3%) had unusual extranodal metastases
in sites such as the kidney, adrenal gland, spleen, and stomach at presentation.[3] In a series by Sweetenham et al., three cases of seminoma metastasizing to the duodenum and stomach were described.[4] Only few cases of renal metastasis of seminoma have been reported. Castelán-Maldonado
et al. reported a case of 24-year-old male with metastatic seminoma of the left kidney,
11 months after the orchidectomy done for seminoma.[5] Similarly, our patient presented with metastasis to kidney and colon 2 years after
orchidectomy.
However, placental alkaline phosphatase (PLAP) positivity is seen in 85%–98% cases.
Studies have demonstrated that PLAP is neither a specific nor a sensitive marker for
seminoma. The expression of PLAP may decrease in extragonadal or metastatic seminoma
as compared to primary seminoma.
It is important to diagnose seminoma early because tumor stage is the most important
prognostic factor. Seminomas are extremely sensitive to radiation and chemotherapy,
and these modalities are usually incorporated in the treatment following orchiectomy.
Cure rates exceeding 95% can be expected for these patients. For metastatic seminoma,
treatment by platinum-based combined chemotherapy is preferred.
Conclusions
This is a rare case of pure seminoma with metastasis to para-aortic lymph node, kidney,
and colon 2 years after orchidectomy. There was striking granulomatous reaction, and
PLAP stain was negative. To conclude, proper clinical history along with the histomorphological
and IHC correlation can aid in the definitive diagnosis of metastatic seminoma, and
negative PLAP staining does not exclude it.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms.
In the form the patient(s) has/have given his/her/their consent for his/her/their
images and other clinical information to be reported in the journal. The patients
understand that their names and initials will not be published and due efforts will
be made to conceal their identity, but anonymity cannot be guaranteed.
