https://orcid.org/0000-0002-7610-1807
To the Editors:
Colorectal cancer is the third most common cancer in the world.1 Ulcerative colitis (UC), a well-known risk factor for colorectal cancer,2–4 may pose diagnostic dilemmas due to a substantial clinical overlap. We discuss a case with both UC and colorectal cancer diagnosis and highlight how the UC flare may closely mimic the latter.
A 46-year-old male patient, with a diagnosis of UC for 10 years, presented to the emergency department with bloody diarrhea. He reported a stool frequency of 12- to 16 episodes/d. Although he had achieved clinical remission with corticosteroids and oral 5-aminosalicylates in the past, he was noncompliant with the treatment regimen in the recent past. Before presenting to our emergency department, he was at another hospital where his bloody diarrhea was attributed to acute severe UC, prompting a week of treatment with intravenous hydrocortisone. However, as the diarrhea was steroid-refractory, he was referred to our center for further evaluation. At presentation, he was tachycardic (heart rate: 132 beats/min) and hypotensive (blood pressure: 90/62 mm Hg). Physical examination revealed pallor, bilateral pitting pedal edema, and palpable bilateral inguinal lymph nodes. While the abdominal examination was unremarkable, digital rectal examination revealed hard circumferential thickening of the rectum.
Laboratory investigations were suggestive of anemia (hemoglobin 83 g/L), leukocytosis (17 000/µL), hypoalbuminemia (21 g/L), uremia (85 mg/dL), and elevated serum creatinine (4.5 mg/dL). The x-ray film of the chest showed moderate bilateral pleural effusion. As steroid-refractory bloody diarrhea in the context of the aforementioned set of clinical and laboratory abnormalities was concerning for a new underlying pathology, sigmoidoscopy was performed for further evaluation. It showed circumferentially infiltrated and ulcerated rectal mucosa with a nonnegotiable narrowing at 10 cm from the anal verge (Figure 1A). Histopathological findings were suggestive of a diagnosis of signet ring cell carcinoma (SRCC) in the background of chronic colitis (Figure 1B). Pleural fluid cytology and fine needle aspiration from inguinal lymph nodes confirmed metastatic disease. The patient was managed conservatively. On day 10, serum creatinine decreased to 1.2 mg/dL. The patient was counseled about the prognosis of the disease and available treatment options. The patient had grade 3 Eastern Cooperative Oncology Group performance status at discharge. He was scheduled for chemotherapy on an outpatient basis.
A, Endoscopic image showing circumferentially infiltrated and ulcerated rectal mucosa. B, Photomicrograph of rectal biopsy showing glands lined by high-grade dysplastic epithelium surrounded by sheets of tumor cells with signet ring morphology (hematoxylin and eosin, ×500).
The prevalence of colorectal cancer in UC is 0.8% to 1.4%.2–4 The most common histological variant is adenocarcinoma. Other less common variants include mucinous and SRCC. SRCC usually arises from the stomach and is uncommonly described from the breast, lung, bladder, pancreas, gallbladder, and colon. SRCC is rarely reported in patients with UC.5 Our case, which highlights a rare histological variant of colorectal cancer, has 2 critical implications in the context of a preexisting diagnosis of UC. First, patients with UC should be periodically screened for colorectal cancer early in their lives. Second, refractoriness of UC symptoms to treatment regimens that were previously effective in achieving remission and emergence of newer systemic signs or symptoms should prompt urgent, appropriate, and adequate investigations to rule out colorectal cancer.
Acknowledgments
Informed consent taken from the patient for publication of the relevant clinical data. All measures have been taken to preserve the identity of the patient. Dr. Abhishek Lenka (Washington DC, USA) reviewed the manuscript for English.
Author Contributions
A.Y., A.J., J.S., U.D., and A.K.S. were involved in the primary management of the patient and the conceptualization of the initial manuscript draft. K.A. and K.V. were involved in the histopathological evaluation. A.J. and A.K.S. critically revised the manuscript. All authors approved the final manuscript.
Funding
None.
Conflicts of Interest
None.
