When a Tattoo Reaction Turns out to Be a Good Pre-EUS-FNA Warning Sign

Abstract

Malignant melanoma is one of the aggressive malignancies which can metastasize to multiple sites. Endoscopic ultrasound is a good modality to diagnose metastatic lesions as it can access multiple sites in chest and abdomen. Developing a new mass lesion in chest or abdomen in patients with melanoma can be challenging to diagnose, EUS can help in obtaining tissue sample for accurate diagnosis. Our case is a 26 year-old female patient presented for evaluation after positive PET scan results. She had history of persistent lump in the right axillary area for about 5-6 months for which she underwent biopsy which showed metastatic melanoma. She was a previous smoker. Her paternal grandfather had history of melanoma and her father had history of squamous cell carcinoma of the mandible. PET-CT scan showed an active spot in the left adrenal gland concerning of metastatic melanoma in addition to abnormal activity in the right axilla (Figure 1). Patient was referred for endoscopic ultrasound which showed left adrenal gland mass measured 16 x 17 mm (Figure 2a). EUS-guided FNA was done. Cytology confirmed the diagnosis of metastatic melanoma (Figure 2b). Patient underwent right complete axillary lymph node dissection and left laparoscopic adrenalectomy. After discussing the treatment options with the patient, she was started on Ipilimumab and finished 2 cycles. Because the patient was having intermittent RUQ pain, abdomen and chest CT scan was done which showed new mediastinal lymph nodes, along with multiple pulmonary and peritoneal nodules. On detailed questioning, the patient also reported developing new skin nodules at her right thigh tattoo (Figure 3). To identify whether these new changes were secondary to metastatic disease versus immunological reaction from the chemotherapy, EUS guided FNA of mediastinal lymph nodes in addition to biopsy of the skin lesions at the tattoo site were done. Both biopsies showed non-necrotizing granulomas consistent with immunological reaction with no evidence of malignancies. The patient was started on prednisone and had complete resolution of the skin tattoo nodules and marked improvement in her abdominal pain. Repeated CT scan showed improvement on mediastinal lymph nodes. The combination of detailed medical history taking and clinical evaluation, in addition to the valuable use of EUS guided FNA, were essential for correct diagnosis of this patient condition to guide the appropriate management.Figure 1Figure 2Figure 3