CRA25 UTILITY OF PET-CT IN THE DIAGNOSIS OF LUNG METASTATIC ALPHA-FETOPROTEIN-PRODUCING DUODENAL ADENOCARCINOMA: A CASE REPORT

Authors
Nyuk Fei Wong1, Larry Ellee Nyanti1,2, Anthony Kim Tee Lim3, Nurul Atiqah Mak Nasukhat3, James Emmanuel4, Nusaibah Azman5, Mohamad Aizat Abdul Aziz5, Meryl Grace Lansing1,2, Subramaniam Ponnuvew1, Shah Min Lo1, Nai Chien Huan1, Hema Yamini Devi Ramarmuty1, Kunji Kannan Sivaraman Kannan1

Affiliation
1Department of Respiratory Medicine, Queen Elizabeth Hospital, Kota Kinabalu.
2Medical Department, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah.
3Oncology Department, Hospital Wanita dan Kanak-Kanak Sabah, Kota Kinabalu.
4Gastroenterology Department, Queen Elizabeth Hospital, Kota Kinabalu.
5Department of Pathology, Queen Elizabeth Hospital, Kota Kinabalu.

Introduction

Duodenal adenocarcinoma is infrequent and constitutes only 0.5% of all gastrointestinal tumors with a reported 14.3% leading to lung metastasis. Alpha-fetoprotein-producing duodenal adenocarcinoma has been only sporadically reported, and to our knowledge, never reported in the context of lung metastasis. 

Case report

A 63-year-old male, ex-smoker of 45 pack years, with no underlying cirrhosis, presented with hemoptysis for two days. Physical examination was unremarkable. Alpha-fetoprotein levels were significantly elevated at 18146.5 IU/ml while CA 19-9 and CEA levels were normal. Contrast-enhanced computed tomography (CT) showed a left upper lobe lung mass measuring 7.9 x 5.4 x 7.7cm with normal liver, pancreas and bowel. Histopathological examination of CT-guided left lung biopsy revealed metastatic adenocarcinoma positive for CK20 and Pan-CK, negative for CK7, Napsin A, TTF-1, P40, chromogranin and synaptophysin, likely primary colorectal. A follow-on Positron emission tomography (PET)-CT demonstrated FDG-avidity in a D2 segment duodenal mass (SUVmax 20.53) and the left upper lobe mass (SUVmax 17.58). OGDS examination revealed nodular mass at D1, and biopsy was performed, confirming duodenal adenocarcinoma positive for CK7, CDX2, mucicarmine, BerEP4 and CK19 and negative for CK20, TTF1, Hepa1, p40 and PAX8. Molecular studies revealed no eGFR mutation. A final diagnosis of duodenal adenocarcinoma with lung metastasis was made and patient was commenced on chemotherapy (FOLFOX regimen).

Conclusion

This case highlights a challenging case of duodenal adenocarcinoma with lung metastasis. PET-CT can be useful in guiding OGDS biopsy in instances whereby the primary lesion is not apparent on CT.