While inguinal hernia is common in the primary care office, the differential diagnosis is extensive and includes infectious, inflammatory and neoplastic processes. Varicocele is another frequent, generally benign condition which occasionally reflects serious disease entities. Left-sided or bilateral varicoceles account for the overwhelming majority of varicoceles because the left gonadal vein drains into the left renal vein in contrast to the right gonadal vein, which drains directly into the inferior vena cava, thus making left-sided or bilateral venous congestion more likely. Presence of an uncommon unilateral right-sided varicocele thus warrants further radiological workup, in particular CT abdomen and pelvis, to evaluate for retroperitoneal pathology. We describe a case in which appropriate use of a variety of imaging modalities including testicular ultrasound and CT led to an important diagnosis of a large, well-differentiated liposarcoma in the right retroperitoneum of a patient with a right-sided groin mass.
Depending on the source, liposarcoma is described as either the most common or second most common type of soft tissue sarcoma (STS) in adults comprising 24% of extremity STS and 45% of retroperitoneal STS [
Liposarcomas can develop in any location in the body. The most common sites are the thigh and retroperitoneum. In the extremity, the tumor may present as a soft, painless mass which enlarges at any number of speeds ranging from slowly across years to rapidly across months. Retroperitoneal liposarcoma most often presents as an asymptomatic abdominal mass, though infrequently patients will present with symptoms caused by the effect of the growing mass on adjacent structures (incomplete obstruction, gastrointestinal bleeding, and pain) [
The World Health Organization categorizes liposarcoma into five distinct histologic subtypes: well differentiated, dedifferentiated, myxoid, pleomorphic, and mixed-type. CT and MR imaging findings may provide clues about the particular histology of a lesion suggestive of liposarcoma [
The purpose of this case report is to describe how appropriate radiological workup of a patient who presented with a mild right-sided groin mass led to the diagnosis of a large, retroperitoneal well-differentiated liposarcoma which extended through the right inguinal canal.
A 63-year-old gentleman was found by his primary care physician to have a new right inguinal canal impulse bulge upon presentation for an unrelated symptom. The patient was referred to a general surgeon, to whom he reported a one year history of an asymptomatic groin mass and possible urinary changes. On physical examination, the abdomen was soft, slightly obese, nontender, and nondistended. There was mild right testicular tenderness with a right inguinal canal impulse bulge. The left testicle was normal and there was no left inguinal canal impulse bulge.
Ultrasound ordered to evaluate hernia contents and rule out testicular pathology demonstrated a mild, unilateral right-sided varicocele measuring 3 mm (Figure
Right testicle doppler ultrasound, transverse superior view, showing right-sided varicocele with mild dilatation (3 mm) of vessels of the pampiniform plexus. There was no corresponding dilatation of vessels of the left pampiniform plexus.
A CT abdomen/pelvis with intravenous contrast was performed in order to rule out a mass in the right retroperitoneum that could have been compressing the right gonadal vein and causing venous congestion. This CT demonstrated a
CT abdomen and pelvis with IV contrast, transverse image, displaying a large fatty lesion with associated soft tissue component (starred) in the right peritoneum anterior to the iliopsoas muscle. There is displacement of the bowel loops anteriorly and to the left.
CT abdomen and pelvis with IV contrast, coronal image, demonstrating a large fatty lesion with associated soft tissue component in the right peritoneum extending into the right lower quadrant along the right paracolic gutter measuring
The white arrow on Figure
The patient’s metastatic workup (chest CT with IV contrast) was negative and he underwent tumor resection. Surgical exploration demonstrated an obvious large, palpable, lobulated mass encapsulated within regular adipose tissue of the right retroperitoneum. The mass was removed with wide margins. Frozen section of the
Pathology confirmed the diagnosis of well-differentiated liposarcoma (Figure
Photomicrograph of pathology of lipomatous retroperitoneal mass. Microscopic pathology. This is a composite photomicrograph which demonstrates representative findings from the initial surgical specimen in this case. (a) Low power representative field of the patient’s surgical specimen which demonstrates adipocytes, sclerosis, and inflammation (hematoxylin and eosin stained section, 40x magnification). (b) Lipoblasts are indicated by the black arrow and while being a common feature of liposarcomas are not necessary for diagnosis of liposarcoma (hematoxylin and eosin stained section, 400x magnification).
Due to positive microscopic margins, the patient proceeded to resection of residual disease including right orchiectomy, omental flap, and appendectomy at an outside, regional sarcoma center six months after the initial surgery. One microscopically positive margin persisted. The patient did not undergo any radiation or chemotherapy as part of his treatment.
Now two and a half years after his initial diagnosis, this gentleman continues to be monitored for local and distant recurrence of disease with biannual abdominal/pelvic CTs and annual chest X-rays.
Patients are frequently seen by primary care physicians and general surgeons for the evaluation of a groin mass. Inguinal hernia is a common cause of a bulge in the groin and the differential diagnosis for hernia sac contents extends beyond fat and bowel, including intraperitoneal hemorrhage from ruptured abdominal aortic aneurysm or splenic rupture, metastatic deposits, abdominal tuberculosis, ascites, appendicitis, appendicular abscess, endometriosis, and even uterus in pseudohermaphrodite [
This patient’s groin mass was initially evaluated by testicular ultrasound, which demonstrated no testicular lesions or definite bowel-containing hernias. However, there was a mild unilateral right-sided varicocele. Unilateral right-sided varicoceles constitute only 7% of all varicoceles. Varicoceles are most frequently unilateral left-sided (68%) or bilateral (25%) due to the difference in venous drainage of the right and left testicles [
The patient we describe appropriately underwent CT abdomen/pelvis to rule out right retroperitoneal pathology and was found to have a large right retroperitoneal lipomatous mass, most likely liposarcoma, which extended into the scrotum and could account for both the physical exam finding of right inguinal hernia and the unilateral right-sided varicocele. Pathology ultimately confirmed the diagnosis of well-differentiated liposarcoma. In retrospect, the liposarcoma was not detected in the scrotum by the initial ultrasound as the mass was fatty and indistinguishable from normal adipose tissue. It was also likely nonmobile, which would make it difficult to detect on valsalva as opposed to mobile, fat-containing inguinal hernia.
Well-differentiated liposarcoma accounts for approximately 50% of liposarcomas, with the most common site being the lower extremity (50%) followed by the retroperitoneum (20%) [
On CT and MR, well-differentiated liposarcoma appears as a predominantly adipose soft tissue mass with nonlipomatous components [
The large size of the nonlipomatous tissue foci suggested dedifferentiated liposarcoma. Because dedifferentiated liposarcoma arises within the context of well-differentiated liposarcoma, most of the radiological features are the same. However, nodules of nonlipomatous tissue >2 cm in size can indicate that the lesion is dedifferentiated liposarcoma, though this diagnosis must be confirmed histologically [
Clues about the histological subtype of liposarcoma are especially critical given that it is the most important prognostic factor. Outcomes vary widely depending on the liposarcoma subtype: well-differentiated liposarcoma has the best prognosis with five-year survival rates of 90% or higher whereas pleomorphic liposarcoma has five-year survival rates reported to be as low as 30% [
Complete resection of the tumor with wide margins is the primary treatment of liposarcoma [
The differential diagnosis of lipomatous tumors includes lipoma, the five types of liposarcoma, hibernoma, and lipoblastoma [
In summary, we report a case of a large, well-differentiated liposarcoma in the right retroperitoneum that was diagnosed as a result of thorough follow-up of incidental right-sided inguinal hernia, including imaging studies. The hernia was identified by the patient’s primary care physician during evaluation for another complaint. This case demonstrates (1) the importance of thorough physical examination and (2) the need to avoid premature closure in diagnosis of groin masses. Not all groin masses are simple hernias, and hernia cases have the potential to reflect distant disease processes. The rarity of a right-sided varicocele reflects the fact that the right gonadal vein drains directly into the inferior vena cava and is therefore much less likely to manifest venous congestion in the absence of left-sided congestion. Unilateral right-sided varicocele warrants CT follow-up to rule out retroperitoneal pathology causing compression of the right gonadal vein. In this case, CT also provided valuable insight into the histology of the discovered retroperitoneal lesion.
No portion of the manuscript, including images, contains patient-identifiable information.
The authors declare that there is no conflict of interests regarding the publication of this paper.
Sophia K. McKinley prepared paper including literature review, writing, and editing. Nicolas Abreu prepared manuscript including literature review, writing, and editing. Eva Patalas prepared manuscript including editing. Arthur Chang prepared manuscript including editing.
The authors would like to acknowledge the Cambridge Health Alliance, the Harvard Medical School Cambridge Integrated Clerkship, Dr. Anatoli Shabashov, Dr. Ketan Sheth, and Dr. David Elvin for their support.