Laser Removal of Buccal Skin Coloration Caused by India Ink Injection for Cancer Marking

A 66-year-old woman with gingival cancer of the left maxilla was scheduled for surgery after preoperative chemotherapy and radiotherapy in the oral surgery department of another hospital. Because the preoperative treatment carried the possibility of obscuring the localization of the tumor, the patient underwent marking with India ink. Her buccal skin showed a change in color the same day. On initial examination, the left buccal mucosa showed extensive blue coloration, and the skin side showed blue changes from the cheek to the neck (Figure 1). Because dynamic chemotherapy had already been started and external irradiation and surgery were already scheduled, laser irradiation was started 1 month after the surgery for gingival cancer (3 months after the erroneous injection). A Q-switched ruby laser was used to irradiate the darkest nasolabial folds. Because improvement was observed, irradiation of the entire discolored area was started. Laser irradiation was performed at an output of 4.0 to 5.5 J/cm² about every 3 months, for a total of 12 treatments. On follow-up after 1 year, treatment was considered completed because the skin tone had improved to a level acceptable to the patient (Figure 2).

In the field of plastic surgery, crystal violet is often used for surgical marking. However, its short duration means that crystal violet is inappropriate when the marking needs to last more than a month. India ink is used for marking when resecting tumors in the gastrointestinal tract,^1-3 before nonsurgical treatment,⁴ and for marking implants.⁵ Markings in the oral cavity reportedly remain clear for 7 to 16 weeks.⁴ India ink was originally used for calligraphy and painting, and it is also used for tattooing. Made from soot and glue, this ink shows the physical properties of a colloidal ink solution. India ink is sometimes used in the medical field to stain tissues and blood vessels⁶ in addition to marking tumors. For use among patients, sterilized India ink is used as a hospital preparation. Complications can include tissue inflammation and adhesion as well as excessive spreading of the ink, which makes identification of the tumor difficult.^3,7

According to the previous doctor, about 2 mL of India ink had been accidentally injected. In particular, the nasolabial folds and mandibular rim were darker in color compared with the surrounding cheek area, suggesting tattoo-like changes caused by the ink. In the present case, a change in skin color was observed immediately after injection from the mucosal side, suggesting erroneous injection into the facial artery. Based on a study that analyzed vascular territories in the oral cavity,⁶ we speculate that the ink had been injected into the buccal artery area, then entered the facial artery from the buccal artery and stained the skin in the territory of the facial artery. Because the volume of ink injected (2 mL) was considerable, infiltration into the interstitium also occurred, suggesting that all layers of the face were stained from the oral cavity. The optimal amount of India ink to be injected for marking has been reported as 0.01 to 0.1 mL per site.^8,9 Care should therefore be taken when injecting more than this amount.

Several case reports have described unexpected skin staining after intraoral surgical marking with India ink,^10,11 but no treatments were performed in any of them. In this case, excision of the tattooed area, skin transplantation, and laser irradiation were all considered, but laser treatment was chosen as the least invasive option because the patient had recently undergone surgery for gingival cancer.

For the removal of black and blue tattoos, a Q-switched ruby laser, Q-switched alexandrite laser, or Q-switched Nd:YAG laser can be used.¹² Laser treatment is the first choice for accidental tattoos.¹³ In this case, we used the Q-switched ruby laser (Ruby Z1, 694-nm wavelength; JMEC) available at the clinic, and the color tone was acceptable to the patient after 12 treatments, although a blue tinge was still apparent. The Q-switched ruby laser only penetrates to the mid-dermal layer, limiting the effectiveness of treatment in cases with large amounts of pigment in the subcutaneous tissue, as in this case.

One study¹⁴ reported that the ideal marking method before radiotherapy is to make a tattoo with a diameter of 2 to 3 mm at a depth of 1 to 2 mm and an angle of 30^O. As in this case, using a syringe may result in the injection of a larger volume of ink than expected, so dipping the needle in the dye prior to insertion appears preferable. Recently, a sterile carbon particle suspension has been developed as a marking preparation for the gastrointestinal tract and reportedly causes less inflammation and adhesion.⁷ Such methods are expected to prove useful for oral marking.

Many reports have described marking with ink before surgery, radiation, or chemotherapy. To improve visibility and reduce complications, methods using needles instead of syringes or changes in the dye can be considered. If a tattoo is left on the skin, laser treatment is the first choice and has a certain effect, but limitations exist depending on the depth of pigment deposition.

Affiliations: ¹Department of Plastic and Reconstructive Surgery, Graduate School of Medical Sciences, Tokyo Medical and Dental University, Tokyo, Japan; ²Department of Plastic and Reconstructive Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan

Correspondence: Noriko Uemura, MD, PhD; noriplas@tmd.ac.jp

Ethics: The patient provided written informed consent for inclusion of images in this article.

Disclosures: The authors disclose no financial support or conflicts of interest.