Unclassified Sex Cord/Gonadal Stromal Testis Tumour with a Pure Spindle Cell Component: Pathological Features And Review of The Literature

Case Report

Austin J Urol. 2023; 9(1): 1080.

Unclassified Sex Cord/Gonadal Stromal Testis Tumour with a “Pure “Spindle Cell Component: Pathological Features And Review of The Literature

Catherine Cawekazi Cingo¹; Cyril Mnguni²; Meshack Nndweleni Bida³*

¹Registrar, Department of Anatomical Pathology, University of Pretoria and the National Health Laboratory Service, Pretoria, South Africa

²Registrar, Department of Urology, University of Pretoria; Steve Biko Academic Hospital, Pretoria, South Africa

³Department of Anatomical Pathology, University of Pretoria and the National Health Laboratory Service, Pretoria, South Africa

*Corresponding author: Meshack Nndweleni Bida Department of Anatomical Pathology, University of Pretoria and the National Health Laboratory Service, 10 Shingwedzi street; The Wilds; Pretoria; 0167, South Africa. Tel: 012 3542714 Email: meshack.bida@nhls.ac.za

Received: November 21, 2023 Accepted: December 16, 2023 Published: December 22, 2023

Abstract

Background: About 2-5% of adult testicular tumors are classified as sex cord/stromal tumors, which are an uncommon group of tumors of the testis. Occasionally, a small percentage of Sex Cord/stromal Testis Tumors (SCST) that are primarily composed of spindle cells seem to be unclassifiable. There are about six cases reported where spindle cells predominate, four of which are consisting purely of spindle cells. At the morphologic level, a striking resemblance to a fibroma has raised the notion of a possible fibrothecoma, but this is not supported by the immunohistochemistry, and the features are consistent with an unclassified sex cord/stromal tumor with a “pure” spindle cell component.

Description: A 45-year-old man with a firm mass in the lower pole of the left testis for 3 years. The patient had no comorbidities and no features of endocrinopathies. All blood tests were normal. The ultrasound showed a solitary hypoechoic mass with increased blood flow by Doppler scan. A well-circumscribed tumor measuring 30mmx 15mm with no discernible capsule was identified macroscopically. Microscopy showed a well-circumscribed spindle cell lesion with no necrosis, cytological atypia, or mitoses. The tumor cells appeared spindled with eosinophilic cytoplasm, vesicular nuclei, and occasional nucleoli. No nuclear grooves were noted in the tumour cells. No vascular invasion was present. Actin, calretinin, CD99, S100, and inhibin were positively immunoreactive.

Conclusion: The findings were consistent with an Unclassified pure spindle SCST, a rare tumor with a benign course that must be distinguished from several spindle cell neoplasms. There are no biochemical markers for the diagnosis of this tumor, thus requiring meticulous clinical examination, especially if it is small in size.

We report a case of “pure spindle cell sex cord stromal tumour of the testis in a 45 years old man in which the histomorphological as well as the immunohistochemical features are consistent with the diagnosis of unclassified sex cord/stromal testis tumor with “pure” spindle cell component.

Keywords: Unclassified sex cord/gonadal stromal testis tumour with a “pure “spindle cell component; immunohistochemistry

Introduction

Sex cord/stromal tumors of the testis as a group are uncommon, constituting about 2–5% of adult testicular tumors. The majority of patients tend to be children and young adults, constituting about 25% of testicular tumors in infants and children.

There is, however, a wide age range in general, and juvenile granulosa cell tumor is the most common congenital testiculartumor, more common in neonates and infants, associated with ambiguous genitalia or abnormalities of sex chromosomes. Sertoli cell tumors are common before age 1 and often associated with Peutz-Jeghers syndrome and the Carney complex.

Spindle cell tumors, both benign and malignant, are rarely encountered in the testis. The spindle cell morphology of testicular tumors conceptually arouses a variety of tumors, including soft tissue neoplasms. The more common sex cord stromal tumors, such as Leydig cell tumors, Sertoli cell tumors, or granulosa cell tumors, rarely present with spindle cell morphology.

However, cases of conventional sex cord/stromal testis tumors with a spindle cell predominant component that have been reported in the literature are firmly entrenched in the WHO 2016 classification of testicular non-germ cell tumors [1].

These tumors seem to fall into two main groups, viz., biphasic tumors in which the spindle cell component is predominant and intermixed with a conventional sex cord stromal tumor, and one group in which there is a “pure” spindle cell component. Most of these tumors present as a testicular mass, and functional tumors are generally uncommon except for some of those that are intermixed with Leydig cell tumors (unlike ovarian sex cord stromal tumors) or granulosa cell tumors. The tumors often show indolent behavior, with only about 5% showing aggressive behavior. The morphologic prognostic factors include size, mitotic rate, necrosis, cellular atypia, infiltrative borders, and vascular invasion. Clinically, stage is the most important prognostic factor, staged with the TNM, or Children's Oncology Group (COG) staging system, as for germ cell tumors.

Case Report

Clinical Summary

A 45-year-old man was admitted to the Department of Urology of Steve Biko Academic Hospital, Pretoria, South Africa, because of a painless, firm mass in the lower pole of the left testis, which has been present for 3 years.

The patient was otherwise healthy with no underlying systemic disease and, most importantly, no features of endocrinopathies.

The urine analysis, liver enzymes, Prostate-Specific Antigen (PSA), Lactate Dehydrogenase (LDH), serum Alpha-Fetoprotein (AFP), and serum Beta-human Chorionic Gonadotropin (β-hCG) were all normal.

The ultrasound of the scrotum showed a solitary left hypoechoic mass of 13.7mm×17.5mm×14.1mm with increased blood flow detected by Doppler scan (Figure 1). A small hypoechoic nodule in the left epididymis head measuring 6.2x4.1mm was identified. A high left groin node with cortical thickening measuring 4.7mm in diameter was also seen (Figure 2).

Citation: Cingo CC, Mnguni C, Bida MN. Unclassified Sex Cord/Gonadal Stromal Testis Tumour with a “Pure “Spindle Cell Component: Pathological Features And Review of The Literature. Austin J Urol. 2023; 9(1): 1080.