Metastatic squamous cell carcinoma of the colon: a conundrum in colorectal malignancies

Abstract

Small-cell carcinoma of the colon is an extremely rare tumour, with poorly understood pathogenesis and unestablished treatment guidelines. The first case was documented in 1919, and only about 100 cases of this condition have been reported to this date. In this case report, we present a case of sigmoid squamous cell carcinoma that eventually led to bowel perforation and was diagnosed on histopathology after emergent surgical intervention. Additionally, we also review the incidence, epidemiology, pathogenesis, immunohistological markers, neogenomics and therapeutic strategies for the same.

A tumour with two‐and‐a‐half faces—Primary lung adenosquamous carcinoma causing secondary squamous cell carcinoma in the colon

“…Notably, the final diagnosis of ADSQ in our patient was only made possible after the discovery of the SCC in his ascending colon, a malignancy that accounts for less than 1% of colorectal cancers 11 . Due to such rarity of colonic SCC, the possibility of metastasis from other sites should be explored 4,12 . This is especially important for patients with a known primary cancer at a different site.…”

“…11 Due to such rarity of colonic SCC, the possibility of metastasis from other sites should be explored. 4,12 This is especially important for patients with a known primary cancer at a different site. Indeed, this suspicion is what prompted further testing on our patient.…”

“…3 Still, the possibility of metastasis from other locations, including the lungs, should be explored when rare GI cancers are identified, for example, squamous cell carcinoma (SCC) in the colon. 4 We report an unusual case of primary ADSQ in the lung with squamous-component metastasis leading to a secondary SCC in the ascending colon. We highlight the importance of clinical suspicion and comprehensive genetic testing, such as next-generation sequencing (NGS), for confirming the primary tumour site and guiding treatment options.…”

“…Though lung cancers, including ADSQ, have a strong propensity for metastasis to distant sites, spread to the gastrointestinal (GI) tract remains very uncommon, seen in less than 0.5% of lung cancer cases 3 . Still, the possibility of metastasis from other locations, including the lungs, should be explored when rare GI cancers are identified, for example, squamous cell carcinoma (SCC) in the colon 4 …”