Extended pancreato-duodenectomy coupled with adjuvant chemotherapy for SMARCB1/INI1 deficient pancreatic carcinoma: A case report and literature review

Abstract

Introduction SMARCB1/INI1 gene deletion appears to be associated with a rare, malignant and aggressive form of pancreatic carcinoma whose diagnosis is challenging. Our objective is to illustrate that the tumor may masquerade as a duodenal papillary carcinoma, be difficulty to identify on diagnostic imaging and that making an accurate diagnosis may be challenging, however surgical resection may be possible. Case report We present a case of a 24-year old male patient presenting with jaundice and itchy skin, elevated TBIL, AST, ALP and CA125. A 2.2 × 1.7 cm pancreatic nodule, later diagnosed as a SMARCB1/INI deficient pancreatic carcinoma was detected on Endoscopic Ultrasound - Fine Needle Aspiration (EUS-FNA). The patient was successfully treated with extended pancreato-duodenectomy coupled with adjuvant chemotherapy, a 7 × 5 × 5 cm tumor resected. Discussion SMARCB1/INI deficient pancreatic carcinoma has been reported in couple of other articles. However, unlike other cases, in our case identification and accurate assessment of the tumor was particularly difficulty both on imaging and during operation. Our patient has thus far had a positive outcome with no recurrence. Conclusion For rare forms of pancreatic carcinoma, identification and assessment of the tumor size may be challenging on imaging and during operation. However, careful assessment should be performed before ruling out surgical resection. Furthermore, adjuvant chemotherapy may be beneficial to the patient.

Undifferentiated Pancreatic Carcinomas, Clinical Features and Therapeutic Options: What We Know

“…PD-L1 expression was positive in osteoclastic-like giant cells. In rhabdoid pancreatic carcinoma, the neoplastic cells express a loss of INI1 expression [ 16 , 34 , 35 , 36 ]. Osteoclastic-like giant cells are consistently non-reactive with CKAE1/AE3 (pan-cytokeratin) [ 8 , 9 , 12 ].…”

“…There are frequent alterations in KRAS, TP53 and CDKN2A [ 3 , 9 , 14 , 22 , 23 ]. KRAS mutations may be absent in some cases, especially in the rhabdoid subtype [ 30 , 33 , 36 ]. The presence of a KRAS mutation is a hallmark of poor prognosis.…”

“…Homozygous deletions of CDKN2A and CDKN2B have been reported, and so have SMAD4 mutations [ 3 , 22 ]. Rhabdoid carcinoma is marked by a lack of INI1 expression [ 33 , 34 , 36 ]. INI1, also known as SMARCB1, is a core subunit of the SWI/SNF ATP-dependent chromatin remodeling complex.…”

“…Patients with undifferentiated pancreatic carcinoma usually present with generic and nonspecific signs and symptoms [ 9 , 34 ]. Patients may present with jaundice, itchy skin, weight loss, nausea and vomiting and fever [ 8 , 9 , 36 ]. Patients may report vague abdominal and/or back pain and gastric fullness [ 15 , 37 ].…”

“…They may appear hypointense on dual-phase CT. On average, they are larger than PDACs at the time of diagnosis with a mean diameter of 5.3 cm [ 13 ]. In some cases, the pancreatic tumor may mimic other tumors, such as duodenal papillary carcinoma, upon endoscopic retrograde cholangiopancreatography [ 36 ]. In some cases, the neoplasm may not be apparent on CT [ 36 ].…”