Squamous Cell Carcinoma of Colon-an Etiopathological Surprise

The Enigma That is Rectal Squamous Cell Carcinoma: A Case Series

INTRODUCTION

Colorectal cancer is the third most common cancer and the third leading cause of cancer deaths in the United States. As rectal squamous cell carcinoma (SCC) is an uncommon colorectal cancer, there is limited data on this clinical entity. We aimed to evaluate the tumor characteristics, treatment, and clinical outcomes of this rare deadly disease.

METHODS

Pathological specimens from 2017 to 2022 at a single National Cancer Institute-designated cancer center were screened for all rectal cases with a diagnosis of SCC. All patients with a primary rectal SCC were included. Patients who had extension to the dentate line or evidence of an anal mass, and those who were treated at an outside institution, were excluded. Demographic, treatment, outcome, and surveillance data was extracted.

RESULTS

There were 56 specimens identified, nine of which met inclusion criteria. Most patients were White (78%), Hispanic (78%), and female (67%). The average age at diagnosis was 57 y [52-65]. All patients had nodal involvement at the time of clinical staging. All patients were treated with Nigro protocol, with one patient treated with surgery first. The median time of follow-up was 12 mo after initial treatment, 33% had recurrence, with median time to recurrence of 25 mo. Overall, mortality from rectal SCC was 33% at a median time of 37 mo from initial diagnosis.

CONCLUSIONS

Rectal SCC is a colorectal cancer that is not fully understood. Our findings showed that treatment mirrors that of anal SCC, with similar rates of survival to both rectal adenocarcinoma and anal SCC.

Primary Squamous Cell Carcinoma of the Cecum: A Case Report

Primary squamous cell carcinoma (SCC) of the colon is an exceptionally rare diagnosis. The etiology and pathogenesis of this entity remain unclear. It usually presents in patients as an emergency, typically with the tumor in the advanced stage. We report a case of SCC of the cecum presenting with perforation, initially diagnosed as SCC of unknown origin. The patient underwent a limited right hemicolectomy and end ileostomy outside our center. The patient was referred to us for further workup and possible adjuvant chemotherapy. She was assessed clinically and found to have had poor appetite and anorexia for a month, with an intermittent fever documented at 39 degrees. Thus, the patient was elected to get admitted for a septic workup and re-staging by CT scan and tumor biomarkers. CT showed a phlegmon and abscess formation at the right iliac fossa that was attached to surrounding structures, including the abdominal wall. Drain placement at the site of the phlegmon was attempted but failed due to bowel overlapping. Therefore, the patient was booked for surgical exploration and drainage, where all structures were resected en bloc. Histopathological examination revealed well-differentiated keratinized SCC with lymph node metastasis. The diagnosis of primary SCC of the cecum was confirmed after investigations to rule out primary sources were negative. Surgical resection remains the mainstay of management, with a possible role for chemotherapy and radiation therapy. The prognosis in these cases is usually poor. This warrants early diagnosis and management. Studies are needed to establish a management protocol for this entity.

Squamous cell carcinoma of ascending colon with pMMR/MSS showed a partial response to PD-1 blockade combined with chemotherapy: A case report

Primary colon squamous cell carcinoma (SCC) is extremely rare and associated with a poor prognosis. Moreover, there is no treatment guideline for this disease. Proficient mismatch repair/microsatellite-stable (pMMR/MSS) colorectal adenocarcinoma is refractory to immune monotherapy. Although the combination of immunotherapy with chemotherapy in pMMR/MSS colorectal cancer (CRC) is currently under investigation, the clinical activity of this approach in colorectal SCC remains unknown. In this article, we report the case of a pMMR/MSS CRC patient with ascending colon SCC who had high programmed cell death–ligand 1 (PD-L1) expression and the a missense mutation in codon 600 of the B-Raf proto-oncogene (BRAF V600E) mutation. The patient exhibited a significant response to the combination of immunotherapy and chemotherapy. After eight cycles of treatment with the combination of sintilimab and mFOLFOX6 (oxaliplatin, fluorouracil, and leucovorin), computed tomography–guided microwave ablation of the liver metastasis was performed. The patient achieved excellent durable response and continues to experience a good quality of life. The present case indicates that programmed cell death 1 blockade combined with chemotherapy may be an effective therapy for patients with pMMR/MSS colon SCC and high PD-L1 expression. Furthermore, PD-L1 expression may be a biomarker for immunotherapy in patients with colorectal SCC.

Primary Squamous Cell Carcinoma of the Sigmoid Revealed by Acute Intestinal Occlusion in Moroccan Young Male Patient: A Case Report and Literature Review

Primary colorectal squamous cell carcinoma (SCC) is an extremely rare subtype of colon cancer, with an incidence of less than 1% of colorectal malignancies. We report a case of a 40-year-old male patient admitted to the emergency department with symptoms of acute intestinal obstruction. Histopathological evaluation of colonoscopic biopsies revealed squamous cell carcinoma. A sigmoidectomy was performed. In order to enrich the medical literature, we add our case to the collection of colorectal squamous cell carcinoma cases by analyzing and summarizing the clinical, pathological, and therapeutic features of this rare entity.

Primary sigmoid squamous cell carcinoma with liver metastasis: A case report

BACKGROUND

The pathological type of simple squamous carcinoma in colorectal malignancies is rare. Simple squamous cell carcinoma of the colorectum occurs most frequently in the rectum. The clinicopathological features and biological behaviors of squamous colorectal carcinoma are unclear, and its prognosis may be worse than that of simple adenocarcinoma. Studies on squamous colorectal cancer are currently limited to case reports, and there is no standard treatment protocol. Therefore, more case reports are required to fully understand squamous colorectal cancer.

CASE SUMMARY

We reported the case of a 56-year-old woman who complained of constipation for 2 years. Colonoscopy revealed a sigmoid colon tumor, and the pathological result of colonoscopy was squamous carcinoma. After completing the relevant assessment, the patient was clinically diagnosed with cT4aN0M0, stage IIB, and surgery was performed. Based on postoperative pathological results, the patient was diagnosed with pT4bN0M0, stage IIC. Six cycles of adjuvant chemotherapy were administered after surgery. Liver metastasis and abdominal wall mass were found more than 1 mo after the end of the last chemotherapy session. Targeted local treatment was not performed because the liver had multiple metastases, but I¹²⁵ particle implantation of the abdominal wall mass was performed. Two cycles of first-line chemotherapy were administered after the surgery. The patient underwent 14 mo of treatment and eventually died from the tumor.

CONCLUSION

Squamous carcinoma of sigmoid colon is a rare tumor with unclear pathogenesis. Its clinicopathological diagnosis should be paid close attention.

Clinical and Molecular Characteristics of Rare Malignant Tumors of Colon and Rectum

The most frequent form of colorectal cancer is represented by adenocarcinoma being about 98% of tumor histological types. However, other rare histotypes can be found in colon and rectum (adenosquamous, goblet cell adenocarcinoma, lymphoma, medullary carcinoma, melanoma, mesenchymal, neuroendocrine, plasmacytoma, signet ring, squamous tumors). Altogether, these forms account for less than 2% of colorectal tumors. There are no specific diagnostic or therapeutic recommended approaches and most of the information available from literature derives from small and retrospective clinical series. In the present study, we provide a paramount and updated view on clinical and biologic characteristics of rare colorectal tumors.

Primary Squamous Cell Carcinoma of the Cecum Presenting as Spontaneous Perforation

Squamous cell carcinoma (SCC) of the colon is an extremely rare condition, and its pathogenesis is not fully understood. Bowel perforation is a very infrequent manifestation of colonic SCC, and only a few cases have been reported in the literature involving sigmoid and splenic flexure perforation. To the best of our knowledge, no cases of ileocecal perforation have been documented in the literature. Here we present a case of cecal SCC that presented with bowel perforation, necessitating emergent surgical intervention. Histopathological examination showed SCC with lymph node metastasis. This case reviews current knowledge and highlights the rare manifestation that these rare tumors can present.