An uncommon presentation of metastatic melanoma: a case report

Abstract

Metastases to the spleen are rare and are generally part of a multi-visceral metastatic disease. The most common sources of splenic metastases include breast, lung and colorectal malignancies as well as melanoma and ovarian carcinoma. Solitary splenic metastasis is very uncommon. We present a case of a 44-year-old man who presented at our department for gallstones symptoms. He had a past medical history of neck cutaneous melanoma (T3bN0M0--Stage IIb). He had not attended follow-up schedule for personal reasons. However, abdominal ultrasound revealed the presence of a solitary solid lesion in the spleen. Preoperative workup was completed with CT scan that confirmed the presence of a large splenic lesion with subcapsular fluid collection, also compatible with a post-traumatic lesion.Preoperative findings could not exclude malignancy and patient was therefore submitted to surgery. At laparoscopy, a condition of peritoneal melanosis was present. Splenectomy was carried out. Histological report confirmed the peritoneal melanosis and the diagnosis of metastatic spleen lesion from melanoma. Patient was observed, but died of metastatic disease 14 months after surgery. Splenic metastases are uncommon. Isolated metastases from melanoma are rare and could be found several months after primary diagnosis of melanoma. Surgery remains the most effective treatment, especially for metachronous disease, offering the best chance of long-term survival. Prognosis remains poor, as metachronous disease is indicative of aggressive widespread of the disease.

FIGURE 1

(A) Ultrasound of the spleen showing a large 9 × 8 cm solid lesion at the upper pole, with mixed echogenicity, prevalently hyperechoic, and almost no vascularization; (B) Arterial phase helical CT scan showing a 76 × 76 mm round mass, with dishomogeneous hypodense and high-density areas located at the upper pole of the spleen, with a thick subcapsular fluid collection at the inferior pole (not visible in this section).

FIGURE 2

(A) Intraoperative findings of focal peritoneal melanosis on the epiploon and on the peritoneal surface of the right diaphragmatic peritoneum; (B) massive amount of peritoneal melanosis around the spleen, on gastrosplenic and phrenicocolic ligaments; (C) Surgical specimen showing a large brownish irregular round mass that protrudes above the surface at the upper pole of the spleen; a cut surface shows the dishomogeneous appearance and the intense dark brown color of the lesion, with soft solid component and areas of colliquation.