# Leydig cell tumour of the testis

Source: https://onco.cc/cancers/leydig-cell-tumour/  
OnCo record `leydig-cell-tumour` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Leydig cell tumour is the commonest testicular tumour that is not a germ cell tumour; it grows from the hormone-making cells between the tubules. It often makes testosterone or oestrogen, causing early puberty in boys or breast growth in men, and nine in ten are benign and cured by surgery. No chemotherapy works in the malignant tenth, managed case by case at a specialist centre.

## Summary

Leydig cell tumours are sex cord-stromal tumours of the testis, listed in the WHO classification apart from the germ cell tumours that make up most testicular cancer (Moch 2016). They are the most common non-germ cell neoplasms of the testis and are often hormonally active, producing precocious virilisation in boys or feminisation in adults (JCEM 2006). Malignancy, defined by metastasis rather than by histology alone, occurs in up to 10 percent, with large size, necrosis, vascular invasion, atypia and high mitotic count as warning features; the main differential in boys with congenital adrenal hyperplasia is the testicular adrenal rest tumour, which responds to steroid suppression (Avicenna Journal of Medicine 2013). Germline fumarate hydratase mutations, the cause of the HLRCC syndrome, were found in two of 30 adult Leydig cell tumours, with loss of the wild-type allele and activation of the hypoxia pathway (JCEM 2006).

How it differs from its parent: the testicular page describes germ cell tumours, cured by cisplatin; Leydig cell tumours do not respond to that chemotherapy, do not raise the germ cell markers, and are staged and managed as a sex cord-stromal tumour, with testis-sparing surgery possible for small benign tumours.

How common: no incidence figure in the sources read.

Treatment: radical or testis-sparing orchidectomy for benign tumours; retroperitoneal lymph node dissection for tumours with malignant features or nodal disease; metastatic disease has no effective chemotherapy and is managed case by case (NCI PDQ testicular summary for the germ cell comparison).

## Fields

- Kind: Cancer
- Last checked: 2026-09-24
- Also known as: Leydig cell tumour; Leydig cell tumor; Interstitial cell tumour of the testis; Malignant Leydig cell tumour
- Tags: subtype-page; wave4; testicular; rare
- Group: genitourinary
- Burden: The most common non-germ cell tumour of the testis (JCEM 2006), yet a small minority of testicular tumours; up to 10 percent behave malignantly (Avicenna Journal of Medicine 2013). No registry figure was found in the sources read.
- Biomarkers: Inhibin and calretinin positive; germ cell markers negative; Testosterone, oestradiol and gonadotrophins; Size, necrosis, vascular invasion, atypia and mitotic count (malignancy risk); Fumarate hydratase (rare germline cases)

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/leydig-cell-tumour/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/leydig-cell-tumour/#overview
- Types and stages (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/leydig-cell-tumour/#what-it-is
- Symptoms and diagnosis (on the hub): How this cancer shows itself, how the diagnosis is confirmed, and the biomarkers clinicians test for. https://onco.cc/cancers/leydig-cell-tumour/#finding-it [4 biomarkers]
- Treatment (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/leydig-cell-tumour/#treating-it [1 setting]
- Trials and papers (on the hub): Trials recruiting now, the landmark trials, the trials held by this cancer's subtypes, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/leydig-cell-tumour/#evidence
- Biology and targets (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/leydig-cell-tumour/#science [1 target]
- Countries and centres (own page): Cases by country, the UK and NHS pathway and other country lenses, the expert centres with trials on record, and the centres named on this cancer's subtypes. https://onco.cc/cancers/leydig-cell-tumour/where-you-are/
- Decisions and support (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/leydig-cell-tumour/#living-with-it [6 questions]
- Pipeline and open problems (own page): Everything in development, the medicines held by this cancer's subtypes, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/leydig-cell-tumour/coming/
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/leydig-cell-tumour/data/ [1 connected records]

## Standard of care

- All cases: Orchidectomy (testis-sparing for small benign tumours); retroperitoneal node dissection for malignant features; no chemotherapy has shown benefit in metastatic disease, which is planned case by case at a specialist centre with trials considered. ([Testicular germ cell tumours](https://onco.cc/cancers/testicular/))

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Leydig_cell_tumour
- NCI PDQ: testicular cancer treatment: https://www.cancer.gov/types/testicular/treatment
- Moch 2016, European Urology: the 2016 WHO classification of urinary and male genital tumours, part A: https://doi.org/10.1016/j.eururo.2016.02.029
- JCEM 2006: adult Leydig cell tumours of the testis caused by germline fumarate hydratase mutations: https://doi.org/10.1210/jc.2006-0183
- Avicenna Journal of Medicine 2013: testicular adrenal rest tumour or Leydig cell tumour, case and review: https://doi.org/10.4103/2231-0770.112789

## Connected records

- cancers: [Adult granulosa cell tumour of the ovary](https://onco.cc/cancers/granulosa-cell-tumour/), [Seminoma](https://onco.cc/cancers/seminoma/), [Sertoli cell tumour of the testis](https://onco.cc/cancers/sertoli-cell-tumour/), [Spermatocytic tumour of the testis](https://onco.cc/cancers/spermatocytic-tumour/), [Testicular germ cell tumours](https://onco.cc/cancers/testicular/)
- targets: [FH](https://onco.cc/targets/fh/)

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JSON: https://onco.cc/api/v1/entities/leydig-cell-tumour.json