Local staging of sigmoid colon cancer using MRI

Background

An accurate radiological staging of colon cancer is crucial to select patients who may benefit from neoadjuvant chemotherapy.

Purpose

To evaluate the diagnostic accuracy of preoperative magnetic resonance imaging (MRI) in identifying locally advanced sigmoid colon cancer, poor prognostic factors, and the inter-observer variation of the tumor apparent diffusion coefficient (ADC) values of diffusion-weighted imaging (DWI).

Material and Methods

Using 1.5 T MRI with high resolution T2-weighted (T2W) imaging, DWI, and no contrast enhancement, 35 patients with sigmoid colon cancer were assessed. T-stage, N-stage, extramural vascular invasion (EMVI), and ADC values of the tumors were assessed and blindly compared by two observers using postoperative histopathological examination as the gold standard. Early tumors were defined as T1 to T3ab, and advanced tumors as T3cd or T4.

Results

The accuracy of the two radiologists in staging early versus advanced tumors, N-stage, and identification of EMVI was 94%/89%, 60%/66%, and 77%/60% with an inter-observer agreement of к = 0.86 (95% confidence interval [CI] = 0.67–1.00), к = 0.64 (95% CI = 0.39–0.90), and к = 0.52 (95% CI = 0.23–0.80). All the measured mean ADC values were below 1.0 × 10⁻³ mm²/s with an intra-class correlation coefficient in T3cd–T4 tumors of 0.85.

Conclusion

Preoperative MRI can identify locally advanced sigmoid colon cancer and has potential as the imaging of choice to select patients for neoadjuvant chemotherapy. Initial experience with ADC measurement was achieved with an excellent inter-observer agreement in advanced tumors.

[Penile metastasis from rectum cancer primarily interpreted as Peyronie's disease]

We report an unusual case of penile metastasis derived from a rectal adenocarcinoma, which was first interpreted as Peyronie's disease. The patient had a single palpable mass in the penile shaft within the corpus cavernosum, with no ulceration or pain in the area. Two years earlier he had been treated for rectal cancer with neoadjuvant radiation therapy and abdomino-perineal resection. The mass in the penis later turned out to be a manifestation of widespread metastatic disease. The patient lived three years after discovery of metachronous metastases in penis and lungs.

[Rectal cancer in a pregnant woman, a case report]

A case of disseminated rectal cancer in a 32-year-old pregnant woman is described. Pain was her main complaint, but this had been ascribed to haemorrhoids and treated with topical agents. She was diagnosed with rectal cancer late in the third trimester when her midwife referred her for surgical assessment. Following caesarian section, diagnostic workup showed multiple liver metastases. Rectal cancer in pregnancy is rare, while haemorrhoids are common. We recommend keeping the differential diagnoses in mind and performing a digital rectal examination if pregnant women have anal symptoms.