Primary squamous cell carcinoma of the rectum: An atypical histology

Abstract

Squamous cell carcinoma of the rectum is one of the differential diagnoses of rectal tumors. It represents a low incidence in the population. The etiopathogenesis and the biology of these tumors are unclear, for this reason the gold standard treatment is difficult to establish. We present a 47-years-old woman who had a squamous cell carcinoma in medium rectum. She was treated with radiation therapy and chemotherapy and the treatment was followed by surgical excision.Key words: Rectal cancer. Rectum. Squamous cell carcinoma. Surgery. Radiotherapy. Radiochemotheraphy. INTRODUCTIONSquamous cell carcinoma of the rectum is a rarity within colorectal tumors entity. The incidence of this kind of tumors is estimated at 0.1-0.25 per 1,000 tumors (1). Due to the small number of cases of this disease, the pathogenesis is unclear and it is attributed to different assumptions about the available literature. Although surgery has been considered as the main route of approach, treatment is currently under discussion. CASE REPORTA 47-year-old woman presented with a history of uterine myoma of 10 years evolution and bilateral salpingectomy due to endometriosis. She was studied because of abdominal pain located in lower hemiabdomen, as well as hematochezia and diarrhea, these symptoms accompanied by weight loss during the last month. Physical examination showed a good overall appearance, although a rectal examination revealed a friable mass bleeding to the fingertip friction. The blood test showed hemoglobin levels at the lower limit of normal blood. A colonoscopy showed that the lesion was at 8 cm of the anal verge. It was an exophytic and stenotic tumor with malignant appearance. Biopsies revealed that the rectal mucosa was infiltrated by a squamous cell carcinoma. Immunohistochemistry samples showed CK7 positivity and CK20 negativity with overexpression of p16. HPV 16 was detected by PCR technique. At the cervical cytology and the biopsy by uterine curettage no pathological findings were identified. The computed tomography (CT) showed an irregular mass in the middle rectum as well as lymph nodes in the mesorectal fat with pathological appearance and other smaller unspecified periaortic nodes (Fig. 1). The magnetic resonance imaging revealed a bulky mass of 8 cm in length in the middle rectum with infiltrative appearance which invaded the mesorectal fat and fornix vaginal without cleavage plane (T4CRM+N+) (Fig. 2). The case was discussed by a multidisciplinary committee in our center that decided to perform neoadjuvant chemotherapy with cisplatin and neoadjuvant radiotherapy. After 4 months of treatment, the revaluation clinical tests showed a poor response and surgery was planned. The patient underwent a posterior pelvic exenteration with pelvic peritonectomy and intraoperative radiotherapy. The postoperative histopathological findings were a squamous cell carcinoma of rectum moderately differentiated infiltrating the radial margin pT3N1. Immunohistochemistry tests revealed positivity for AE1, AE3, CK7 and overexpressio...

Squamous rectal carcinoma: a rare malignancy, literature review and management recommendations

“…For locoregional evaluation, as with rADC, magnetic resonance imaging (MRI) and endorectal ultrasound (ERUS) should be carried out. 34 ERUS is essential at determining the depth of tumour invasion, particularly with T1/2 lesions, 6 as well as excluding an anal origin with rectal extension. For more advanced T3/4 tumours and in order to determine locoregional nodal involvement, pelvic MRI provides improved definition.…”

“… 39 No treatment guidelines (ESMO or NCCN) are available and treatment options are extrapolated from rADC and aSCC. 34 In the past, rSCC treatment has traditionally involved surgery with significant morbidity (13%-46%) and mortality (1%-7%), 39 , 40 in some cases preceded or followed by radiotherapy and/or chemotherapy. 6 At the beginning of the 20th century, surgery was progressively abandoned with a shift towards CRT.…”

Treatment paradigm and prognostic factor analysis of rectal squamous cell carcinoma- a retrospective study

“…In the past, surgery was the standard treatment. (9) In recent years, chemoradiotherapy (CRT) is the preferred treatment. (10) Most studies believe that radiotherapy (RT) can signi cantly improve the overall survival (OS), local recurrence and distant metastasis of patients with rSCC.…”

The first comprehensive genomic characterization of rectal squamous cell carcinoma

“…While rADC are treated with radiotherapy (RT) combined with chemotherapy of 5-fluorouracil (5-FU) followed by surgery [ 1 , 15 ], aSCC are treated with definitive radiation therapy with concomitant chemotherapy of mitomycin C (MMC) and 5-FU, setting aside surgery in case of local recurrence [ 15 – 19 ]; for rSCC, no clear recommendations exist. In the past, surgery was the standard of care, based on retrospective and observational studies [ 20 ]. More recently, small series have hinted that definitive concomitant chemo-radiotherapy (CRT), lead to high rates of partial or complete pathological response as well as organ preservation [ 20 ].…”

“…In the past, surgery was the standard of care, based on retrospective and observational studies [ 20 ]. More recently, small series have hinted that definitive concomitant chemo-radiotherapy (CRT), lead to high rates of partial or complete pathological response as well as organ preservation [ 20 ]. Our study aims at clarifying the role of HPV in rSCC as well as comparing rSCC, aSCC and rADC molecular profile.…”