Neuroendocrine tumours (NETs) are a diverse group of cancers that arise from neuroendocrine cells, which produce hormones and regulate bodily functions. While the majority of NETs occur in the digestive tract, pancreas, and lungs, rare NETs can develop in uncommon locations such as the head and neck, thymus, kidneys, genitourinary tract, breast, and skin.
Because these unusual NETs are not well recognised, their symptoms can often be mistaken for other conditions. This delays diagnosis, which can lead to disease progression before appropriate treatment is initiated. Understanding the symptoms of NETs in uncommon locations is crucial for early identification and improving patient outcomes.
Neuroendocrine Cancer Australia (NECA), is dedicated to assisting individuals diagnosed with NETs and their loved ones. NECA offers a wealth of resources, educational programs, and advocacy efforts aimed at deepening the understanding of NETs, improving patient care, and encouraging research advancements. Patients can engage with NECA’s comprehensive support and information by calling the NET nurse line.
Some NETs can be considered rare cancers, but certain subtypes are even more uncommon because they develop in atypical locations. While gastrointestinal and pancreatic NETs are the most frequently diagnosed, NETs in the head, neck, kidneys, and skin make up a much smaller percentage of cases.
Due to their rarity, these tumours may not be immediately suspected, leading to delayed or incorrect diagnoses.
The location of a NET determines how it presents in the body. Symptoms may be caused by:
Recognising location-specific symptoms is essential for healthcare providers to suspect and diagnose rare NETs early.
Neuroendocrine tumours of the head and neck are rare, but they can develop in the nasal cavity, sinuses, salivary glands, and thyroid. Symptoms often mimic common sinus or dental issues, leading to misdiagnosis.
Thymic NETs arise in the thymus gland, located in the chest behind the sternum. These tumours may be asymptomatic for long periods, but when symptoms do appear, they often include:
Thymic NETs can secrete hormones that cause paraneoplastic syndromes (indirect effects of a tumour via hormones, cytokines, or immune response), the most well-known being Cushing’s syndrome, which results from excess cortisol production. Symptoms include:
Due to these non-specific symptoms, thymic NETs are often misdiagnosed as respiratory or endocrine disorders.
NETs in the kidneys are extremely rare and often discovered incidentally during imaging. When symptoms do appear, they may include:
Many renal NETs are detected accidentally during scans for unrelated conditions. Biopsy and histological analysis are required to differentiate from renal cell carcinoma (RCC), a more common kidney cancer.
Genitourinary NETs are uncommon but can develop in the bladder, prostate, and testes. Symptoms vary depending on the exact location.
Some genitourinary NETs can secrete hormones, causing systemic symptoms such as:
Because these symptoms overlap with more common urinary or reproductive conditions, genitourinary NETs are often misdiagnosed.
Breast NETs are rare, accounting for less than 1% of all breast cancers. They often present similarly to other breast tumours, with symptoms such as:
Unlike typical breast carcinomas, breast NETs may:
This means breast NETs may not respond to conventional breast cancer treatments, requiring tailored management.
Merkel cell carcinoma (MCC) is a highly aggressive skin NET that often presents as:
MCC has a high risk of spreading to lymph nodes and distant organs. Early biopsy and imaging are essential for timely treatment.
NETs in the bones are predominantly metastases from another site. Symptoms include:
Metastatic NETs that spread to the bones can weaken bone structure, making fractures more likely.
Because rare NETs mimic more common conditions, they are often overlooked. Delayed diagnosis can lead to:
Given the complexity of NETs, patients with suspected rare or atypical tumours should be referred to NET-specialised oncologists, multidisciplinary teams, and treatment centres. For guidance and support, you can also contact the NECA NET Nurse.
Treatment depends on the tumour’s location, size, and hormone secretion. Options may include:
A key focus for NET care is symptom management, including:
Recognising rare NET symptoms early leads to faster diagnosis, better treatment, and improved patient outcomes.
Further information and support for people diagnosed with NETs is available by calling the NECA NET nurse line.
