Dr Keith Hopcroft continues our series of fascinating but often unrecognised conditions
The case
‘It seems like I'm making a fuss,' said my next patient, a 21-year-old man who very rarely attended the surgery. ‘But I've had this spot on my back and it's really tender.' This was one of those cases where you've made the diagnosis even before you've seen the lesion – obviously an infected sebaceous cyst or a simple abscess. But he dropped a bombshell as he pulled off his shirt: ‘It's been there for about three years.'
So my diagnosis had already unravelled – a fact confirmed when I looked at the ‘spot', which certainly didn't look like a typical infection. The lesion was a dark purple nodule which really did make him jump at the slightest touch. There were no similar lesions elsewhere, he was on no medication and was otherwise perfectly well.
The diagnosis
This was a glomus tumour – an uncommon benign vascular tumour.
Typical features
The most common site is on the distal phalanges, especially around the nail, though glomus tumours can occur anywhere on the body. Typically, they are less than a centimetre in diameter and form a bluish red papule, usually in patients aged between 20 and 40. But their characteristic feature is the tremendous pain they cause – especially when pressed or subjected to temperature change.
Glomus tumours are probably more common than is realised, as misdiagnosis – as naevi or venous malformations – is the norm. One series reported an average diagnostic delay of around seven years.
Treatment
Though harmless, these lesions are best excised. This will provide histological confirmation of the diagnosis – and relief in a very grateful patient.
Issues for the GP
It is not unusual to examine patients who appear hypersensitive to the slightest touch – this usually reflects anxiety, personality or emotional problems, and there are often clues in the past medical history or in the records of previous examinations. This scenario was different, though. Realising this, and being aware of the features of glomus tumour, may save the patient considerable diagnostic delay.
Take-home point
Exquisite tenderness over an apparently trivial and longstanding lesion may not be ‘overlay'. Consider glomus tumour if the history and appearance fits.
Dr Keith Hopcroft is a GP in Laindon, Essex
Patient with a glomus tumour Glomus tumour
