An unusual presentation of angiomatoid fibrous histiocytoma as a perineo-scrotal swelling

A Mohamad Safwan; Sandeep Bhaskaran Babu; Rachel Abraham; Annes Thivya

doi:10.4103/jms.jms_85_21

CASE REPORT

Year : 2021 | Volume : 35 | Issue : 3 | Page : 122-125

An unusual presentation of angiomatoid fibrous histiocytoma as a perineo-scrotal swelling

A Mohamad Safwan¹, Sandeep Bhaskaran Babu², Rachel Abraham³, Annes Thivya²
¹ Department of General Surgery, Kerala Institute of Medical Science, Kerala Institute of Medical Sciences, Thiruvananthapuram, Kerala, India
² Department of Surgical Oncology, Kerala Institute of Medical Science, Kerala Institute of Medical Sciences, Thiruvananthapuram, Kerala, India
³ Department of Pathology, Kerala Institute of Medical Science, Kerala Institute of Medical Sciences, Thiruvananthapuram, Kerala, India

Date of Submission	08-Jul-2021
Date of Acceptance	21-Feb-2022
Date of Web Publication	15-Jun-2022

Correspondence Address:
A Mohamad Safwan
Department of General Surgery, Kerala Institute of Medical Sciences, Thiruvananthapuram, Kerala
India

Source of Support: None, Conflict of Interest: None

Check

DOI: 10.4103/jms.jms_85_21

Abstract

Angiomatoid fibrous histiocytoma (AFH) is one of the spindle cell neoplasms having fibroblast and myofibroblast origin. The perineoscrotal region is an uncommon site for such tumors and never reported in the literature. We present a 31-year-old gentleman presented with a painless, rapidly growing scrotal swelling for 2 months duration. Guided core needle biopsy demonstrated spindle cell neoplasm; regional magnetic resonance imaging (MRI) revealed a large mass extending from the perineum to inter-testicular space within the scrotal sac. After staging evaluation, he underwent en bloc resection of the tumor. Histopathology showed features of AFH which is supported by immunohistostains positivity to smooth muscle actin, clusters differentiation (CD) 68, CD99, and desmin. Despite any adjuvant treatment, he remained disease-free on follow-up MRI for 4 years. AFH can also have an unusual origin from perineoscrotum, and it grows rapidly and has a good prognosis.

Keywords: Angiomatoid fibrous histiocytoma, perineal sarcoma, perineoscrotal swelling, undifferentiated pleomorphic sarcoma

How to cite this article:
Safwan A M, Babu SB, Abraham R, Thivya A. An unusual presentation of angiomatoid fibrous histiocytoma as a perineo-scrotal swelling. J Med Soc 2021;35:122-5

How to cite this URL:
Safwan A M, Babu SB, Abraham R, Thivya A. An unusual presentation of angiomatoid fibrous histiocytoma as a perineo-scrotal swelling. J Med Soc [serial online] 2021 [cited 2022 Jul 2];35:122-5. Available from: https://www.jmedsoc.org/text.asp?2021/35/3/122/347646

Introduction

Angiomatoid fibrous histiocytoma (AFH) is usually presented as small, often superficial swellings in the lymph nodal regions and extremities and mimicking lymphomas. The perineoscrotal region is an uncommon site for such tumors and never reported in the world literature, to the best of our knowledge. This case is being presented for its atypical site of origin and uncommon presentation as a huge perineoscrotal swelling, to contribute in part to better understanding and awareness of this rare malignancy.

Case Report

A 31-year-old gentleman presented with a painless, fast-growing scrotal swelling for 2 months duration; there was no associated pain, any fever, or antecedent trauma. No history of genitourinary or bowel symptoms or any other accountable predisposing factor was noted. He was married and had a 3-year-old child. He had undergone medical treatment for anemia for 3 years back. Recent bone marrow aspiration was normal.

Physical examination revealed an 18 cm × 12 cm elongated, nontender, well-circumscribed swelling, which is cystic and fluctuant superficially and firm in consistency toward the perineum, with restricted mobility and occupying most of his scrotal sac and pushing his testicles to either side [Figure 1]a, and without testicular, cord, and skin fixity. It extends up to the perineal region along the root of the scrotum, stopping about 2 cm short of the anterior margin of the anal orifice. There was no redness, scrotal edema, or inguinal lymphadenopathy. Per-rectal examination revealed a part of the swelling felt as a firm bulge in the anterior rectal wall.

Figure 1: (a) Lobulated perineoscrotal swelling with superolateral displacement of both testicles pressure effects with edema and necrosis of the most distal part of the scrotal skin is also evident. (b and c) Magnetic resonance imaging showing large perineoscrotal lesion closely abutting urethra and pubic ramus, with altered signal intensity noted in the left obturator internus muscle suggestive of infiltration

Click here to view

Magnetic resonance imaging (MRI) of the pelvis demonstrated a large mass seen extending down from the perineum, expanding through subcutaneous fat reaching the space between the testicles in the scrotal sac. The mass was grossly ellipsoid in shape and had a long axis parallel to the shaft of the penis. The posterior part was insinuating between the root of penile corpus and perineal structures and the posterior margin abutting the anterior surface of the external anal sphincter. No infiltration of the anal sphincters was noted [Figure 1]b and [Figure 1]c.

Ultrasound-guided core needle biopsy showed spindle cell neoplasm. After biopsy, an area of scrotal skin of 3 cm × 3 cm around the biopsy scar developed necrosis and became gangrenous. There were surrounding inflammation and fixity to the scrotal skin for an area of about 7 cm × 3 cm around this. Computed tomography (CT) of the thorax was normal and germ cell tumor markers ruled out paratesticular or extragonadal germ cell tumor.

Under epidural and spinal anesthesia, and in a lithotomy position, an elliptical incision was placed along with the scrotum, encircling the area of skin involved. Right testicle was dissected well away from the tumor. The left testis was closely adherent to the tumor capsule and was also dissected away and safeguarded. The dissection then proceeded posteriorly, and to the left side, left ischiorectal fossa entered, and ischium bone was delineated and bared. Anterior fibers of the puborectalis divided. Anteriorly, the urethra was identified, and the disease capsule was shaved off from the urethra. Bulbospongiosus muscle fibers were split during this step. The dissection then continued deep to the pubic ramus and ischial tuberosity, and the deepest portion of the tumor was mobilized. The entire mobilized swelling was found to be attached to the left ischiocavernosus muscle. This attachment with the muscle was cut well away from the limits of the tumor. Bulbospongiosus muscles resutured around the urethra. Drain inserted. Freely hanging left testis was anchored to adjacent scrotal tissue to prevent future torsion. There was limited space available in the scrotal sac after near-total excision of the scrotal skin and dartos due to tumor infiltration and edema. The residual scrotal skin could be mobilized enough to close around the testicles with minimal tension.

The postoperative recovery was uneventful.

Expert opinion was obtained from Prof./Dr Christopher D. M. Fletcher for histopathology and immunohistochemistry findings. He opined as a solid example of the so-called angiomatoid “malignant fibrous histiocytoma.” The lesion is characterized by a multinodular proliferation of plump mildly atypical spindled or histiocytoid cells, with pale eosinophilic cytoplasm and vesicular nuclei. These nodules of tumor cells are surrounded by a dense fibrous pseudocapsule within which there is a multifocal prominent lymphoplasmacytic infiltrate [Figure 2]a and [Figure 2]b.

Figure 2: (a and b) Histopathology image (×20) showing nodules of tumor cells are surrounded by a dense fibrous pseudocapsule within which there is a multifocally prominent lymphoplasmacytic infiltrate. (c) Immunostains demonstrated multifocally positive for smooth muscle actin (×40). (d) Immunostains demonstrated multifocally positive for clusters differentiation 68 (×40)

Click here to view

Immunostains demonstrated multifocally positive for smooth muscle actin (SMA) [Figure 2]c, clusters differentiation (CD) 68 [Figure 2]d, and CD99 with scattered cells positive for desmin [Figure 3]a.

Figure 3: (a) Immunostains demonstrated scattered cells positive for desmin (×20). (b and c) Follow-up magnetic resonance imaging pelvis with contrast at 4 years demonstrated no local recurrence

Click here to view

After a multidisciplinary tumor board discussion, we kept him for close follow-up for the development of local recurrences. At 4 years since surgery, he remained disease-free and confirmed by follow-up MRI [Figure 3]b and [Figure 3]c.

Discussion

AFH, formerly called angiomatoid malignant fibrous histiocytoma (now re-named as undifferentiated pleomorphic sarcoma), is first described by Enzinger in 1979 and accounting 0.3% of all soft tissue sarcomas.^[1] As per the new World Health Organization classification of bone and soft tissue 2013, it is classified under the category of tumors of uncertain differentiation.^[2]

It has intermediate malignant potential and rarely metastasizes.^[1] It commonly occurs in children and early adulthood as painless swelling involving the deep dermis and subcutis areas of normal lymphoid tissue^[1] and frequently manifests as pyrexia, malaise, anorexia, or anemia due to tumor cytokine production.^[1] The unusual extrasomatic sites are brain,^[3] bone,^[4] lung, mediastinum, breast, ovary, retroperitoneum, and vulva.^[5]

Guided core needle biopsy is mandatory for identifying histological subtypes and grading of the tumor and for treatment planning.^[6] Plain radiographs help demonstrate soft tissue mass and its bony involvement and calcification.^[6] MRI helps in grading, tissue characterization, local staging, and follow-up.^[6] CT chest is needed to rule out detect pulmonary metastasis, especially large tumors from an unusual site.^[6]

The diagnosis must be confirmed by histology which classically demonstrates multinodules of histiocytoid spindle cells with pseudoangiomatous spaces, fibrous pseudocapsules, and lymphocytic cuffs.^[7] Immunoreactivity for the epithelial membrane antigen, CD68, CD99, and desmin,^[7] along with recent ancillary molecular genetic confirmation by reverse transcriptase polymerase chain reaction or fluorescence in situ hybridization detection of EWSR1-CREB1, EWSR1-ATF1, or rarely FUS-ATF1 gene fusions.^[7]

En bloc resection and postoperative follow-up are the cornerstone of management. Chemotherapy and radiotherapy may be rarely needed in cases with distant metastases or multiple local recurrences cases.^[8],[9]

From our case, we recommend to have a strong clinical possibility in any swelling that is larger than 5 cm or showing atypical features such as rapid enlargement, pressure effects, pain, the involvement of nerves and vessels, or fixity to bone or skin.

Our case present had a very dramatic presentation with rapid progression of scrotal swelling and necrosis of a part of the scrotal skin due to pressure effects. However, after complete local resection, our patient did not receive any adjuvant treatment, and it has been 4 years since the resection, there has been no evidence of recurrence clinically and radiologically.

The limitation in our study was we did not examine fusion genes, although we could confirm the diagnosis of AFH without such an analysis.

Conclusion

AFH can also presentation as unusual huge perineoscrotal swelling, the clinician should have AFH as one of the differential diagnosis of such huge swellings for early diagnosis, and it has a good prognosis in young individuals.

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 initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Acknowledgment

We would like to thank Prof./Dr. Christopher D. M. Fletcher (Head of the Pathology Department, Harvard Medical School) for giving an Expert opinion and Dr. Leena Devi (Department of Pathology) and Dr. Jayapraksh Madhavan (Department of Radiotherapy) for sharing knowledge and helping in this case.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Enzinger FM. Angiomatoid malignant fibrous histiocytoma: A distinct fibrohistiocytic tumor of children and young adults simulating a vascular neoplasm. Cancer 1979;44:2147-57.
2.	Antonescu CR, Rossi S. Angiomatoid fibrous histiocytoma. In: WHO Classification of Tumours of Soft Tissue and Bone. 4^th ed. Lyon: IARC; 2013. p. 204-5.
3.	Dunham C, Hussong J, Seiff M, Pfeifer J, Perry A. Primary intracerebral angiomatoid fibrous histiocytoma: Report of a case with a t (12;22)(q13;q12) causing type 1 fusion of the EWS and ATF-1 genes. Am J Surg Pathol 2008;32:478-84.
4.	Mangham DC, Williams A, Lalam RK, Brundler MA, Leahy MG, Cool WP. Angiomatoid fibrous histiocytoma of bone: A calcifying sclerosing variant mimicking osteosarcoma. Am J Surg Pathol 2010;34:279-85.
5.	Chen G, Folpe AL, Colby TV, Sittampalam K, Patey M, Chen MG, et al. Angiomatoid fibrous histiocytoma: Unusual sites and unusual morphology. Mod Pathol 2011;24:1560-70.
6.	Bauer A, Jackson B, Marner E, Gilbertson-Dahdal D. Angiomatoid fibrous histiocytoma: A case report and review of the literature. J Radiol Case Rep 2012;6:8-15.
7.	Kao YC, Lan J, Tai HC, Li CF, Liu KW, Tsai JW, et al. Angiomatoid fibrous histiocytoma: Clinicopathological and molecular characterisation with emphasis on variant histomorphology. J Clin Pathol 2014;67:210-5.
8.	Bernini JC, Fort DW, Pritchard M, Rogers BB, Winick NJ. Adjuvant chemotherapy for treatment of unresectable and metastatic angiomatoid malignant fibrous histiocytoma. Cancer 1994;74:962-4.
9.	Costa MA, Silva I, Carvalhido L, Azevedo I, Alves L, Leal C, et al. Angiomatoid fibrous histiocytoma of the arm treated by radiotherapy for local recurrence – Case report. Med Pediatr Oncol 1997;28:373-6.