INTRODUCTION

Malignant melanoma is most commonly found on the skin and rarely occurs in the rectal region. This case illustrates that rectal melanoma can be misdiagnosed as hemorrhoids. It also aims to add knowledge to possible treatment options for rectal melanoma.

CASE PRESENTATION

We report a case of a 77-year-old Filipino adult presenting with rectal bleeding for three weeks. He underwent sigmoidoscopy that showed thrombosed hemorrhoids; however, subsequent surgical excision biopsy histopathology and immunohistochemistry revealed features compatible with malignant melanoma (HMB45, Melan A, and Cytokeratin positive; CDX2 negative). Staging workup done, including abdominal magnetic resonance imaging (MRI) with IV contrast and chest computed tomography (CT), showed distant metastases. He was then started on pembrolizumab but follow up imaging showed recurrence of the rectal melanoma and progression of metastases. Molecular testing done revealed c KIT/ CD117 positive results, hence, treatment was shifted to imatinib.

DISCUSSION AND RECOMMENDATION

It was seen that rectal melanoma is an aggressive disease; therefore, multidisciplinary management is crucial to yield the best possible outcome, despite its poor prognosis. Such as in this case, using immunotherapy (Pembrolizumab) and targeted therapy (Imatinib) still have inconsistent outcomes, thus, further studies should be pursued. In this patient, both pembrolizumab and imatinib post-surgery resulted to recurrence of the rectal tumor and progression of hepatic and osseous metastases.

Rectal Neoplasms ; Melanoma

BACKGROUND

Post-ERCP pancreatitis (PEP) remains the most common complication following endoscopic retrograde cholangiopancreatography (ERCP). Rectal indomethacin is one of the recommended medications given to prevent pancreatitis in high-risk patients undergoing ERCP.

OBJECTIVES

This study aims to evaluate the effectiveness of diclofenac in preventing PEP, to compare its different routes of administration, and to determine the severity of pancreatitis in patients who develop PEP.

METHODOLOGY

Databases from PubMed, ScienceDirect and COCHRANE Library were searched for randomized controlled trials (RCTs) comparing diclofenac with placebo in the prevention of PEPup to August 2020. Risk ratio at 95% Confidence Intervals (CI) were calculated to evaluate the incidence of the interested outcomes.

RESULTS

Eleven RCTs with a total population of 2,012 were reviewed in this study. Diclofenac was associated with a significant reduction in overall risk of PEP compared with patients with placebo (RR = 0.59; 95%, 0.47 0.74; P < 0.000001), with a mild heterogeneity (P = 0.05; I2 = 41%). Subgroup analyses showed that rectal diclofenac was the superior choice to significantly reduce the overall incidence of PEP(RR = 0.34; 95%, 0.23-0.51; P < 0.000001).

CONCLUSION

Rectal diclofenac significantly reduces the risk of PEPand therefore, should be recommended as routine for clinical use in adult patients who will undergo ERCP.

Anti-inflammatory Agents, Non-steroidal ; Diclofenac ; Pancreatitis