Scrotal Skin Metastasis from Rectum Adenocarcinoma
A 65-year-old man reported in March 2010 with rectal bleeding and tenesmus. Colonoscopy demonstrated an exophytic and ulcerated lesion at the lower rectal region (the tumor was 3 cm superior of the anal verge obstructing 1/3 of intraluminal pathway). Incisional biopsies confirmed the presence of adenocarcinoma of the rectum. Computed tomography (CT) of abdomen and pelvis demonstrated a locally invasive distal rectal neoplasm, without evidence of distant metastases. Magnetic resonance imaging (MRI) of a pelvic region confirmed a locally advanced neoplasm. Therefore the tumor was a radiologically T3 N0 M0 low rectal cancer.\nIn April 2010, preoperative chemoradiotherapy with a total dose of 5040 cGy, given in 28 fractions, five days per week was applied. As a concomitant chemotherapy he received 5-Fluorouracil given in five days bolus injection (400 mg/m2) plus folinic acid (30 mg/m2) per day during the first and fifth weeks of radiotherapy. Then, he was scheduled for low anterior resection six weeks following the completion of chemoradiotherapy. Pathological stage was T4 N0 M0. After the surgery, he received a boost dose of radiotherapy (10 Gy in 5 fractions) due to positive radial margins. He was subsequently treated with 2 cycles 5FU-FA chemotherapy.\nIn June 2011, one year after surgery, PET/CT (18-Fluorodeoxyglucose positron emission tomography based computerised tomography) demonstrated a recurrence in the lower part of the rectum (Suv max: 10.76). At that time there was no pathologic evidence of recurrence, so the patient only followed up.\nIn January 2012, subsequent PET/CT showed a progression of the rectal recurrences, including the spermatic cord with increased FDG uptake (Suv max: 22.15). Ultrasonography demonstrated a slightly thickening of the skin of the left scrotum. The patient had the painless, hazelnut-sized slightly reddish nodules affecting the skin of the left scrotum (). The nodular lesions were up to 14 mm in diameter. The patient then underwent an excisional biopsy from the left scrotal nodules. Macroscopic examination revealed four noduler formations; the bigger one being 3.5 cm. In microscopic assessment; the tumors were under the squamous epithelium and to form atipic glandular formation (). This gland formations consist of cells with scanty cytoplasm, hyperchromatic nuclei and atypic epithelial feature (). Biopsy of the skin compared with the original rectal cancer material, both tumor have same histopathology (). Resection margin was also involved with the tumoral tissue.\nAt this stage, the patient was given orally twice a day, Xeloda (Capecitabine) treatment (1250 mg/m2, in total; 2500 mg/m2). He also received palliative radiotherapy to the left scrotal region with electron beams. Radiotherapy was applied with 6 MeV energy, 300 cGy daily fractions, a total dose of 4500 cGy. During treatment and in the early period, we saw only grade 2 skin side effects according to RTOG acute toxicity criteria. Then, as a late side effect we observed grade 2 skin toxicity (patichy atrophy and hair loss) and grade 3 subcutaneous toxicity (severe induration and contracture). The patient is still alive without any distant metastasis after the therapy which was initiated 12 months ago.