Abstract
BACKGROUND:
The presence of pigment in axillary lymph nodes (LN) secondary to migration of tattoo ink can imitate the appearance of a blue sentinel lymph node (SLN) on visual inspection, causing the operator to either miss the true SLN or excise more than is needed.
OBJECTIVE:
We present patients with tattoos ipsilateral to an early stage breast cancer who underwent a SLN biopsy.
METHODS:
Patients were retrospectively reviewed from medical records and clinicopathologic data was collected. A total of 52 LNs were retrieved from 15 patients for sentinel mapping and 29 of them had tattoo pigmentation on pathologic evaluation.
RESULTS:
Of those 29 SLNs, 2 of them (6.9%) were pigmented, but did not contain either blue dye or Tc-99m (pseudopigmented SLN). Two (3.8%) SLNs were positive for metastasis; both of these had either blue dye or Tc99m uptake, and 1 demonstrated tattoo pigment in the node.
CONCLUSIONS:
In this cohort of patients with ipsilateral tattoos, removed more LNs lead to unnecessary excision which may important for increasing the risk of arm morbidity from SLN biopsy. However, the presence of tattoo pigment did not interfere with understaging for axillary mapping and it did not effect of pathological identification of SLNs positivity.
Introduction
Tattooing involves deposition of pigment using indelible ink into the dermal layer of the skin to create body art via repetitive piercing of the skin with ink-filled needles [1,2]. Close to one in four American women has at least one tattoo (23%) [3]. Intradermal deposition of tattoo ink can cause an acute inflammatory reaction in the dermis that recruits macrophages. The pigment is then transported to regional lymph nodes (LN) in 3 days via pigment-laden macrophages where varying degrees of inflammatory reaction in these LNs can be observed. The pigment persists in the LNs, even if it is removed by laser surgery or dermabrasion on the skin [1,4].
An axillary LN stained with tattoo pigment can be mistaken for a blue sentinel LN (SLN). The possibility of intraoperatively confusing a LN with tattoo pigment in patients with breast cancer (BC) has been evaluated only by a few case reports in the literature [1,5]. Some concern in these cases is BC understaging due to excision of only the pseudopigmented LNs and missing the true SLNs, or increased arm morbidity, as a result of excising more LNs than necessary. Herein, we present a series of patients with BC who had ipsilateral tattoos and evaluate the effect of the tattoo pigment on the SLN biopsy.
Methods
Electronic pathology records with keywords “extracellular anthracotic pigmentation” and/or “pigment-laden macrophages” were retrospectively searched. Then, we reviewed the medical records of patients with BC who had ipsilateral tattoos and underwent SLN biopsy. Data collected included age, number of LNs removed, number of positive LNs, number of LNs with tattoo pigment, uptake of blue dye or Tc-99m in the LN, type of surgery, pathologic stage, tumor grade and hormone receptor status.
All procedures were performed by dedicated breast surgeons at a single institution. All SLN biopsies were mapped with a combination of technetium-labeled sulfur colloid (Tc-99m) and blue dye using lymphazurin. Microscopic evaluation of the LNs was done by routine hematoxylin and eosin staining (Fig. 1). Receptor status was determined by IHC staining. All specimens were evaluated by a breast pathologist. A LN was defined as a pseudopigmented LN if it was pigmented with tattoo ink but did not contain either blue dye or Tc-99m on pathologic evaluation.
Results
A total of 15 patients were identified. The median patient age was 45 years (range: 30–74). All patients were female. The main clinicopathologic features of the 15 patients are shown in Table 1. The average number of LNs retrieved was 3.5 (range: 2–6). A total of 52 LNs were retrieved and 29 (55.8%) of them had tattoo pigmentation on pathologic evaluation. Of those 29 LNs, 27LNs (93.1%, 27/29) demonstrated uptake of blue dye and/or Tc-99m, and 2 of them (6.9%, 2/29) were pseudopigmented SLNs. Seven LNs were palpable and suspected for metastasis at perioperative inspection but none of them had tattoo ink, blue dye and Tc-99m were included for the analysis. Two SLNs (2/52, 3.8%) were positive for metastasis; both of these had either blue dye or Tc99m uptake, and 1 demonstrated tattoo pigment in the node. Eight nodes had black pigmentation and were all blue, but none of them had Tc-99m uptake. Table 2 shows the characteristics and dyeing pattern of the removed LNs.
Discussion
Staging the axilla with a SLN biopsy is the current standard of care in early stage BC [6]. Successful identification of the SLN with a combination of blue dye and technetium labeled sulfur colloid injection is achieved in 97.2% of cases with a false-negative rate of 9.8% [7]. In patients with tattoos, a potential pitfall in the identification of a true SLN during surgery can occur due to migration of tattoo dye causing LN pigmentation that is mistaken for a LN with blue dye uptake [1,5]. Retrieval of pseudopigmented SLNs may also lead to removal of a greater number of axillary LNs than necessary, increasing the risk for arm morbidity. In BC survivors, lymphedema incidence has been significantly reduced by SLNs biopsy, but it has not been completely eliminated. According to ACOSOG Z011 and IBSCG-23 studies, incidence of lymphedema following SLNs biopsy is reported to be 2% and 3%, respectively and 3–7% in other studies [8–10]. The rate of lymphedema is also known to be higher in patients who have over 5 SLNs removed [10]. In our study, three patients had removal of 5 or more nodes, and one of them has pseudopigmented SLN. Conversely, this can be of particular concern if only blue dye is used for SLN mapping and a single pseudopigmented SLN is retrieved, leading to potential understaging of the axilla and increasing false negative rate in these cases. The NSABP B32 trial demonstrated that removal of more than one SLN significantly reduces the false negative rate [7] and ALMANAC study showed that the false negative rate in patients who had three or more SLNs removed was significantly lower than in patients who had only one SLN [11]. In reference to the use of dual mapping agents, using a combination of blue dye and radioisotope has been more successful than using only a single agent in identifying a SLN [11]. At least 2 LNs which identified by lymphazurin and Tc-99m were removed for axillary mapping in our study. Pseudopigmented LNs did not cause understaging of the axilla in our small cohort of patients. Two pseudopigmented nodes removed as SLNs might be retrieved unnecessarily. On the other hand, 8 nodes with no Tc-99m uptake had black pigment and were also blue LNs, therefore they are designated as SLN. Blue staining is hard to detect in black pigmented nodes. Since, true SLNs and pseudopigmented SLNs cannot be distinguished by visual inspection indicating that more LNs than necessary may be removed during SLN resection when operating on BC patients with skin tattoos.
In conclusion, information of the presence or history of tattoos in patients with BC should be kept in mind by the surgeon. BC patients with tattoos should be informed that a greater than necessary number of LNs may be retrieved during SLNB as it cannot be distinguished by visual inspection. In addition, understaging of axilla can be prevented by dual injection with blue dye staining and Tc-99m in patients with tattoos.
None