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Urology Journal

UNRC/IUA

Epithelioid Type of Paratesticular Leiomyosarcoma:

A Case Report and Literature Review

MOHAMMADI TORBATI P1*, ZHAM H2

1Department of Pathology, Shaheed Labbafinejad Medical Center, Shaheed Beheshti University of

Medical Sciences, Tehran, Iran

2Department of Pathology, Mahdieh Medical Center, Shaheed Beheshti University of 

Medical Sciences, Tehran, Iran

KEY WORDS: leiomyosarcoma, scrotal mass, testicular tunica

Vol. 1, No. 3, 215-217 Summer 2004

Printed in IRAN

Introduction

Paratesticular leiomyosarcoma is a rare neopla-

sia, which has been reported in less than 100

cases so far. According to its prevalence, this neo-

plasia is originated from testicular tunica (48%),

spermatic cord (48%), epididymis (2%) and dartos

muscle, as well as subcutaneous tissue of scrotum

(2%).(1,2,3) This lesion is seen in all age groups.

However, it is mostly diagnosed in the 6th decade

and more than 80% of patients are over 40 years

old.(4) Leiomyosarcoma is the result of neoplastic

transformation of smooth muscle cells or multipo-

tential mesenchymal cells in various sites of the

body.(1,5) The behavior of these lesions depends

on the site of origination, but little is known for

grading of such tumors in paratesticular

region.(4,6) Like other mesenchymal tumors of this

region, leiomyosarcoma is manifested as a pain-

less mass without hydrocele and the disease may

be symptomatic in less than one year. Size of

tumor is usually between 2 and 9 cm with a mean

of 5 cm. Almost all cases are primary lesions

rather than the extension of a retroperitoneal

lesion.(2)

Case Report

An 18-year-old male was referred with a pain-

less, firm, and gradually growing right scrotal

mass. The history, physical examination, and

ultrasonographic findings, which indicated a solid

oval mass were compatible with testicular tumor,

thus, radical orchidectomy was performed.

Macroscopically, a firm solid homogeneous

gray-white mass with a dimension of 52 × 39 mm

involving a relatively large area of tunica albug-

inea was observed. However, no sign of testis

involvement was seen. The mass had a clear

demarcation without degenerative changes

(fig. 1).

Spindle cells with delicate eosinophilic cyto-

plasm within crossed or vertically decorated

bands were noted in microscopic study.

Furthermore, a considerable part of lesion with a

different microscopic feature consisted of irregu-

lar tubules, cellular masses, and trabeculae made

by a range of cubic to flat epithelioid cells were

seen as well as different amounts of eosinophilic

cytoplasm, some of which were vacuolized (fig. 2).

The above-mentioned findings suggested three

differential diagnoses: adenomatoid tumor,

epithelioid leiomyosarcoma, and malignant

mesothelioma.

Immunohistochemical stain was used to differ-

entiate the lesions from each other and the

results were as follows:

Accepted for publication in August 2003

*Corresponding author: Department of Pathology,

Shaheed Labbafinejad Medical Center, Boustan 9,

Pasdaran, Tehran, Iran. Postal code: 16666.

Tel: +98 21 2549010-16, Fax: +98 21 2549039.

FIG. 1. Gross appearance of the tumor



EPITHELIOID TYPE OF PARATESTICULAR LEIOMYOSARCOMA:

A CASE REPORT AND LITERATURE REVIEW

1. Negative reaction with calretinin marker,

thrombomodulin, and cytokeratin cocktail;

2. Strong positive reaction with vimentin,

smooth muscle actin, muscle specific actin,

and desmin (fig. 3). 

The findings were compatible with the diagno-

sis of leiomyosarcoma. Following the final diagno-

sis, abdominal and chest CT scan were performed

to rule out any other neoplastic origin.

Discussion

The low prevalence of this disease has limited

the evaluation of its clinical course and the adap-

tation of a therapeutic regimen with high confi-

dence.(7) However, there are two basic points

which should be concerned; firstly, considering all

differential diagnoses of spindle cell paratesticu-

lar tumors and to assure leiomyosarcoma diagno-

sis, and secondly, grading of leiomyosarcoma.

Differential diagnoses are as follows.(6)

1- Subcutaneous scrotal leiomyoma: this tumor

could have polyomorphic nucleus, but two

mitoses in every HPF indicates sarcomatous

change.(8)

2- Malignant mesothelioma: it is usually mani-

fested with the development of progressive

hydrocele, and contrary to leiomyosarcoma, it

has an infiltrative margin. Sarcomatoid

mesothelioma has an extremely collagenized

background. Differentiation is made by

immunohistochemical staining.(9,10)

3- Fibrosing inflammatory pseudomotors: They

are always associated with a significant

inflammation. When inflammation severity is

more than usual in leiomyosarcoma or inflam-

matory pseudomotor positively reacts with

desmin, diagnosis would be difficult. Cases of

fibroblastic proliferation of pseudosarcoma

such as nodular fasciitis are reported in this

region. These tumors have mitosis but their

nuclei are pale, regular, and spindle shape.(11)

4- Deep invasive fibromatosis: it has an infiltra-

tive growth and it is completely firm. This

lesion consists of wavy myofibroblastic or

fibroblastic bands within an extremely collage-

nized background. Immunohistochemical

staining and electronic microscopy are used

for differentiation.(12)

The grading of paratesticular leiomyosarcoma

is based on the evaluation of the number of

mitoses (the mean number of mitoses in 5 HPF

in a part of tumor with the highest mitosis rate

and cellularity), the percentage of necrosis and

the severity of nuclear pleomorphism. These are

important in predicting biologic behavior:

Grade 1: Tumors with no necrosis, less than 6

mitoses in 10 HPF, and mild disseminated

pleomorphism.

Grade 2: Tumors with focal necrosis (<15%), more

than 6 mitoses in 10 HPF, or obvious nuclear

pleomorphism.

Grade 3: Tumors with vast necrosis (>15%),

regardless of the number of mitoses or the

severity of pleomorphism.

Significant regions with epithelioid change, like

what has been seen in this case, was only report-

ed in 4% of cases.(13,14)

The considerable increase in the number of

mitoses in this region which is associated with

serious biologic behaviour, is a remarkable point.

In brief, attention to the following points is rec-

ommended:

1. Since the lesions are mostly low grade and

have better biologic behavior, grading of parat-

esticular leiomyosarcoma would be of great

importance. Grade 3 lesions are extremely

invasive.(7,15)

2. The results of long-term follow-up of patients

216

FIG. 2. Epithelioid cells arranged in solid sheets FIG. 3. Immunoreactivity with desmin, clone: D33



EPITHELIOID TYPE OF PARATESTICULAR LEIOMYOSARCOMA:

A CASE REPORT AND LITERATURE REVIEW

indicate that the use of radiotherapy following

radical orchidectomy decreases local recur-

rence and distant metastasis, particularly in

grade 3 lesions.(15)

3. Since the tendency to hematogenic metastasis

is high, the effect of retroperitoneal lym-

phadenectomy is unclear and generally not

suggested.(16)

4. Immunohistochemical staining of more than

40% of nuclei with Ki-67 marker indicates poor

prognosis; therefore, this staining is suggested

to be added to other criteria for tumor grad-

ing.

5. It seems that chemotherapy has only a pallia-

tive role.(17)

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4. Donovan MG, Fitzpatrick JM. Paratesticular leiomyosar-

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5. Bianchi G, Tallarigo C, Lotto A. About Two cases of

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