Simultaneous giant adrenocortical and renal cell carcinoma associated with lead exposure from residual gun pellets after shotgun injury: case report

A case of simultaneous adrenocortical and renal cell carcinoma due to long-term lead exposure from residual gun pellets is a rare and relatively unknown topic in the literature. We present a 43-year-old male patient with a giant retroperitoneal tumor. Thirteen years before he had a shotgun injury of the left upper side of the abdomen and residual gun pellets are present in the abdominal wall. Extirpation of the tumor and the left kidney was performed. Histopathological examination described adrenocortical and renal cell carcinoma. Continuous and long-term exposure to toxic lead effects from residual gun pellets and traumatic injury represent likely carcinogenic factors in the presented patient.


Background
Renal cell carcinoma (RCC) accounts for 2-3% of all adult malignant neoplasms. One of the possible environmental etiological factors for the development of RCCs described in the literature is lead compounds. Possible mechanisms for lead carcinogenesis are interference with DNA synthesis and repair. [1] Significant data are confirming that retained gun pellets raise lead concentrations in blood, but there is little literature on its possible long-term carcinogenic effects on those patients. [2] Adrenocortical carcinoma (ACC) is a rare malignancy and most of the patient with ACC are adults, with a slight female predominance.
The purpose of this case report is to present a patient who has been diagnosed with renal cell carcinoma and ipsilateral adrenocortical carcinoma at the site of a previous gunshot wound, thirteen years after injury, with remaining pellets in the tissue surrounding the kidney.

Case presentation
We present a 43-year-old male who attempted suicide in 2005, inflicting upon himself a wound to his upper left abdomen, followed by surgery, resulting in a partial colon resection due to injury. Some of the gun pellets were not extracted from the site.
Thirteen years later, he presented with fatigue, weight loss, and anemia. Mild pain in the left superior part of the abdomen was noticed; hematuria is not registered. Symptoms lasted for three months before a medical examination started. After a thorough examination and diagnostics were conducted, it was evident that he had a palpable mass under the lower left rib cage, on the same side as the previous gunshot wound. A CT scan was then performed which showed a huge tumorous mass, 21 cm in diameter, adjacent to the left kidney and remnants of gun pellets scattered around this area (Fig. 1). Open surgery was performed through the left thoracoabdominal incision with partial resection of the tenth rib, and complete extirpation of the tumor, including the kidney, was performed (Fig. 2). The pathological diagnosis was formulated as follows: "A sample, 24 × 18 × 13 cm in size, consists of a kidney, 12 cm in height, surrounded by fatty tissue, and a well-confined, irregular tumor, 12 cm in height. On the lower kidney part, there is a tumor, 5 cm in diameter, with histopathological characteristics of a renal clear cell carcinoma, Fuhrman grade 2. The tumor, positioned by the kidney, matches adrenocortical carcinoma, with vimentin, synaptophysin, and CD56 being diffusely positive, and inhibin and calretinin focally positive. EMA, CK, CK7, p-63, s-100, desmin, chromogranin A, CD 10, CD34, CD 45 and CD 117 are negative" (Fig. 3). The postoperative course was complicated by a mild pancreatic leak at drainage, which spontaneously resolved during the hospitalization. The patient was discharged from the hospital in good physical condition. Blood lead concentration was tested after surgery, during follow-up and was 19 µg/dL. One year after the surgery, on CT no local tumor recurrences or metastases are visible. Further oncological monitoring is carried out.

Discussion
The toxic effects of lead exposure are well known and documented in the literature. Prolonged exposure results in the accumulation of lead in the bones and kidneys. The association between lead exposure and renal tumors has been demonstrated in laboratory animals and in several human studies [1] There are few case reports of tumors resulting from the long-term toxic lead effect from shotgun wounds such as oral carcinoma [3], and metastatic bronchial carcinoma. [4]. Retained bullet fragments can be the cause of systemic lead poisoning [5]. Long-term exposure and high levels of lead are the main risk factors for carcinogenesis. [1] Our patient has moderately high blood lead concentration and developed anemia as a systemic symptom. The organs that developed the tumors were surrounded by gun pellets (Fig. 1), so a local impact of the lead is also plausible. Simultaneous RCC and ACC have not been described often, so a rare case of concomitant tumors of that origin is presented in this article. Only one other case reported simultaneous homolateral renal and adrenal carcinoma [6]. When compared to similar case reports in the literature, the authors come to the conclusion that, in their best knowledge, this is a unique case of renal cell carcinoma with concomitant adrenocortical carcinoma emerging at the site of the shotgun wound with residual pellets, without previous pathology regarding the kidney or the adrenal gland.