Granuloma caused by sea urchin spine

Case contributed by Dr Balint Botz


Slowly developing painful swelling over the dorsal aspect of the interphalangeal joint of the left thumb. The patient reported a puncture injury in the region about 6 months earlier, caused by a sea urchin. The patient removed the spine without seeking further medical attention.

Patient Data

Age: 50
Gender: Male

X-ray of the affected left thumb demonstrated a small calcified tubular foreign body in the soft tissues in the dorsal aspect of the interphalangeal joint, corresponding to the painful, swollen region. The finding was highly suspicious of a retained fragment of the sea urchin spine.


Ultrasound also demonstrated a thin linear echogenic foreign body, surrounded by hypoechogenic pathological tissue with markedly increased vascularity (Courtesy of Dr. Nándor Faluhelyi).

Case Discussion

A local excision of the lesion (positioned extraarticularly, below the extensor tendon) was performed, and the resected tissue was sent for histopathological analysis. The official report demonstrated granulation tissue with the presence of foreign-body giant cells, with a small amount of inflamed synovial tissue. Altogether the findings are in line with the diagnosis of sea urchin granuloma. 

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Case information

rID: 57007
Published: 4th Dec 2017
Last edited: 5th Dec 2017
Inclusion in quiz mode: Included
Institution: University of Pécs

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