|Year : 2022 | Volume
| Issue : 2 | Page : 149-151
Epithelioid sarcoma: A rare neoplasm of the soft tissues found in a pelvic swelling
Niharika Bisht1, Sankalp Singh1, Arti Sarin2, Richa Joshi3, Nishant Lohia4, Manoj M Gopal5
1 Department of Radiation Oncology, Command Hospital (CC), Lucknow, Uttar Pradesh, India
2 Department of Radiation Oncology, INHS Asvini, Mumbai, Maharashtra, India
3 Department of Surgical Oncology, Command Hospital (CC), Lucknow, Uttar Pradesh, India
4 Department of Radiation Oncology, Command Hospital (Air Force), Bangalore, Karnataka, India
5 Department of Pathology, Command Hospital (CC), Lucknow, Uttar Pradesh, India
|Date of Submission||18-Jan-2022|
|Date of Decision||31-Jan-2022|
|Date of Acceptance||06-Feb-2022|
|Date of Web Publication||3-Aug-2022|
Dr. Sankalp Singh
MBBS, DNB (Radiation Oncology), Radiation Oncologist, Army Hospital (R&R), Delhi - 110 010
Source of Support: None, Conflict of Interest: None
Epithelioid sarcoma (ES) is a rare, clinically polymorphic tumor that afflicts the dermal and subcutaneous region of distal extremity of young adults. In the distal extremity, the involvement of pubic and inguinal region is very rare. We present a case of an epithelioid sarcoma of the pubic region, which was managed, with a combination of upfront surgery and adjuvant therapy, and is presently disease free 5 years after completion of treatment.
Keywords: Epithelioid sarcoma, neoplasm, radiotherapy
|How to cite this article:|
Bisht N, Singh S, Sarin A, Joshi R, Lohia N, Gopal MM. Epithelioid sarcoma: A rare neoplasm of the soft tissues found in a pelvic swelling. J NTR Univ Health Sci 2022;11:149-51
|How to cite this URL:|
Bisht N, Singh S, Sarin A, Joshi R, Lohia N, Gopal MM. Epithelioid sarcoma: A rare neoplasm of the soft tissues found in a pelvic swelling. J NTR Univ Health Sci [serial online] 2022 [cited 2023 Feb 4];11:149-51. Available from: https://www.jdrntruhs.org/text.asp?2022/11/2/149/353212
| Introduction|| |
Epithelioid sarcoma (ES) is an uncommon soft tissue malignancy that is usually slow growing and accounts for <1% of all soft tissue sarcomas (STS). Enzinger first described it as a distinct entity in 1970. These sarcomas are classified into a “distal type” that occurs in the upper and lower extremities and a “proximal type” that appears in the trunk and pubic area. The proximal sub type is rare and associated with a poorer prognosis. We present one such case of proximal epithelioid sarcoma which was a challenge regarding diagnosis and management.
| Case Report|| |
A 56-year-old male presented to our hospital with complaints of a swelling over his lower pelvic region since 3 months. The patient gave a history of similar swelling in the same region around 2 years ago for which he had undergone wide local excision in another hospital. The histopathology from the previous surgery was not available. The patient had now relocated away from his earlier city of residence and now presented with the above history to our outpatient department (OPD). On clinical examination the swelling was 30 × 40 mm in size, hard, and fixed to the underlying structures. The skin overlying the swelling was indurated and showed a healed surgical scar. There were no palpable inguinal lymph nodes and the scrotum was normal. A contrast enhanced magnetic resonance imaging (MRI) of the pelvis showed a large heterogeneous mass lesion (50 × 40 × 60 mm) in the muscular plane of the soft tissue anterior to pubic symphysis with heterogeneous enhancement suggestive of a lymph nodal mass or a sarcoma [Figure 1]. With the clinical suspicion of a recurrent neoplastic mass, the patient underwent a core biopsy of the swelling, which revealed it to be a soft tissue sarcoma of the epithelioid lineage. A metastatic evaluation of the patient by a positron emission tomography (PET) computerized tomography (CT) showed a fluorodeoxyglucose (FDG) avid soft tissue lesion in the prepubic region with surrounding fat stranding along with mildly FDG positive inguinal nodes. No distant metastases were observed. The patient underwent a wide local excision of the tumor with sublay mesh hernioplasty and reconstruction with pedicled anterolateral right thigh and left gracilis thigh flap. Inguinal lymph node dissection was also done. Intra-operatively there was a hard, fixed mass around 6 × 8 cm in the prepubic space, adherent to the rectus muscle. The histopathology of the excised mass showed features of high-grade malignant neoplasm with epithelioid morphology. Mitosis was 10/10 per high power field with numerous atypical figures. The immunohistochemistry was positive for cytokeratin (CK), epithelial membrane antigen (EMA) and CD34 with a Ki67 index of 25–30%. All margins were free and all dissected inguinal lymph nodes were reactive. The final impression was that of a recurrent epithelioid sarcoma. In view of locally recurrent disease and high grade of the tumor the patient underwent adjuvant radiotherapy to the left inguinal region to a dose of 60 Gy in 30 fractions on a Theratron 780E telecobalt machine using 2-dimensional planning and conventional radiotherapy delivery. The patient developed grade 2 skin reactions during the treatment which was managed conservatively without any treatment breaks. The patient has been on regular follow-up with local evaluation of the operated site every 3 months, and a contrast-enhanced CT (CECT) abdomen and pelvis every 12 months and is presently disease free for the past 5 years.
|Figure 1: Axial section of pelvic MRI shows a heterogeneous mass lesion (red circle) in the soft tissue plane anterior to the pubic symphysis|
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| Discussion|| |
Epithelioid sarcoma is a rare malignant soft tissue tumor of mesenchymal origin. They are divided into proximal and distal subtype based on their location. The proximal subtype occurs predominantly in adults (13–80 years; median 40), with a slight predominance in men. Though less common, the proximal variant is known to have a more aggressive and locally recurrent course. These are painless, superficially located, slow-growing, solitary, or confluent multinodular tumors in the dermis or soft tissues. In our patient, the presentation was with a painful inguinal swelling and the patient had locally recurrent disease. Lymph node involvement, young age at first diagnosis, female sex, and small size of tumor (<5 cm) is better prognostic factors. Our patient was a middle-aged male with a large-sized tumor and had locally recurrent disease.
The diagnosis of the disease involves good clinical examination, imaging to evaluate local disease infiltration and distant metastasis, and finally histopathological confirmation. We evaluated the resectability of the tumor with a contrast-enhanced MRI (CEMRI) of the pelvis and the metastatic evaluation was done with a PET CT. Histopathology was diagnostic of the disease: grossly, it is a glistening, gray-tan tumor; microscopy shows nodular infiltration and central necrosis. The tumor cells are large, polygonal or rounded with abundant eosinophilic cytoplasm, vesiculous nuclei, and prominent nucleoli. Proximal ES has excess cytologic atypia, rhabdoid features, and lacks a granuloma-like pattern (the latter is occasionally present in the distal ES). Immunohistochemical (IHC) staining has the following pattern: positive for cytokeratins, vimentin, and epithelial membrane antigen (EMA). Desmin and CD34 staining are variable. Smooth muscle actin, CD31, S100, HMB-45, and neurofilament are negative. There are different pathological subtypes described: angiomatoid, inflammatory granuloma, epithelial tumor, achromic melanoma, and epithelioid sclerosing fibrosarcoma. In our patient, the immunohistochemistry was positive for CK, vimentin, EMA, and CD34, hence the diagnosis of epithelioid sarcoma was given. The tumor tissues also showed loss of nuclear expression of INI-1 protein which is encoded by the SMARCB1 tumor supressor gene and shows loss of expression in a range of malignant tumors including ES [Figure 2].
|Figure 2: (a) Hematoxylin and eosin stained section (scanner view) showing epidermis (black arrow) and a tumor (blue arrow) involving the deep dermis. (b) High power magnification shows epithelioid cells with central pleomorphic vesicular nuclei with prominent nucleoli and moderate dense eosinophilic cytoplasm. (c) INI-1 immunostain showing loss of nuclear expression of the tumor supressor gene in tumor cells. (d) Vimentin immunostain showing intense and cytoplasmic positivity in tumor cells|
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Surgical resection with wide margins is the mainstay of treatment. The patient underwent wide local excision two times, with the second surgery also involving inguinal lymph node dissection. Though lymph node dissection is controversial, a PET CT of the patient had showed mildly FDG avid inguinal nodes. However the histopathology yield of the dissection was negative. Even with wide enbloc excision or amputation of the region, the reported recurrence rate of this sarcoma is 34–77% and the metastasis rate is about 40% with common site of metastasis being lung, bone, and brain. Adjuvant radiotherapy was considered in this case in view of poor prognostic factors, high-grade tumor, and locally recurrent disease. Though high-quality evidence is not available for the role of radiotherapy in this disease, however in view of the high-risk factors mentioned above, the case was discussed in a multimodality tumor board with a consensus to offer him adjuvant radiotherapy. Postoperative radiation therapy (RT) has been shown to improve local control in patients with high-grade extremity STS with positive surgical margins. Our patient has been disease free for the past 4 years. Definitive chemoradiotherapy is reserved for surgically unresectable tumors and has inferior outcome compared to tumors that undergo surgery. Chemotherapy agents such as doxorubicin, ifosfamide, gemcitabine, and pazopanib have been used in concurrent setting with radiation or in metastatic disease, but chemotherapy may not confer a survival advantage.
| Conclusion|| |
This case report highlights the management of the proximal variant of epithelioid sarcoma, which is a rare malignancy. We also highlight the role of adjuvant radiation in a locally recurrent setting in a patient with poor prognostic factors.
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.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]