A healthy old man, aged 43, presented with complaint of a slowly growing mass within the tattoo on his right upper arm. According to him, the mass started appearing about 2 years ago, which comes out to be 18 years after his tattoo completion. He also reported treating it at home with 17% salicylic acid liquid wart and 70% isopropyl alcohol. He denied any symptoms such as fever or chills etc. But the question remains, “Why did the mass appear anyway?”
Physical Examination of The Tattoo
Physical examination revealed an exophytic, verruciform and ulcerated plaque in the center A red border covered this 2.6 by 2.5 cm plaque and it drained yellow fluid from its center. The doctors could palpate its deep part as it spread locally into the subcutaneous tissue. However, the lymph nodes came negative indicating no spread to axillary or any other nodes.
Histological Examination and Diagnosis
Based on the physical examination, doctors rolled in differentials such as dimorphic fungal infection, atypical mycobacterial infection, squamous cell carcinoma and sarcoidosis. This made a histological examination imperative. And rightly so, it demonstrated some confirmative findings. The plaque consisted of large cells called histiocytes. These cells had eosinophilic cytoplasm with a vesicular nucleus. Also they displayed a slow mitotic rate. An immunohistochemistry provided further grounds for a definitive diagnosis. It came out positive for S100 and CD68 and negative for cytokeratin 8/18 and Melan A. Based on these findings, the doctors made a diagnosis of granular cell tumor or GCT.
The Next Step?
As one would expect, doctors excised the tumor completely. A post-surgical pathological assay did not reveal any malignant potential. Additionally, tissue culture of the mass for a fungal or atypical mycobacterial infection turned out negative. So Yes, the doctors made an accurate diagnosis.
Reference
1- AAD
