Multiple Subcutaneous Nodules Leading to the Diagnosis of Colon Cancer

Abstract Cutaneous metastasis refers to the growth of cancer cells in the skin originating from an internal cancer. The incidence of subcutaneous metastasis from a visceral malignancy, excluding malignant melanoma, lymphoma, and leukemia, is rare with an incidence of 5.3%. Skin involvement, as a presenting sign of a silent malignancy, is a rare event occurring in approximately 0.8%. Here, we report an interesting case of a 39-year-old man who presented with multiple subcutaneous nodules over anterior chest and forehead for the past 3 months. Physical examination showed nontender, firm to hard multiple subcutaneous nodules ranging from 1 to 2 cm in size. The patient also reported unintentional weight loss and altered bowel habits. Complete blood count showed hemoglobin of 8.0 g/dL, with mean corpuscular volume (MCV) of 97 pg/mL and carcinoembryonic antigen (CEA) of 480 IU/mL. Fine-needle aspiration of the cutaneous nodules revealed malignant cells arranged in a glandular pattern with intraglandular mucin, as well as hyperchromatic and vesicular nuclei with prominent nucleoli. Imaging of the abdomen revealed asymmetrical circumferential thickening with luminal narrowing of cecum and ascending colon and mild ascites with no evidence of liver metastasis. Microscopic examination of the ascending colonic mass showed malignant cells with similar microscopic features. Patient was managed with multiple blood transfusions, and palliative right-sided hemicolectomy was performed in view of intermittent constipation. Sixteen cycles of postoperative chemotherapy were given, after which the subcutaneous lesions regressed and the CEA came down to 56 IU/mL. Skin metastases from colorectal cancer are extremely rare and further analysis of the biology of this mode of metastases may shed light on mechanisms of metastases to specific organs and hopefully provide guidelines for novel targeted therapeutic interventions.