Giant desmoid fibromatosis of the pancreas.

A 15-year-old girl had abdominal distension and appetite loss with episodic heartburn and vomiting for approximately 2 months, but gained 3 kg of weight. Physical examination revealed a huge and hard abdominal mass. Tumor markers including α-fetoprotein, β-human chorionic gonadotropin, carcinoembryonic antigen, CA125, and CA19-9 were all normal. Computed tomography disclosed a gigantic solid mass, occupying the whole abdominopelvic cavity (Fig. 1). Notably, the pancreas was only identifiable by its head and contiguous splenic vein. However, this tumor neither involved other intraabdominal vital structures nor caused paraaortic lymphadenopathy. Core needle biopsy showed hypocellular collagenized spindle-cell neoplasm without nuclear hyperchromasia and atypia, suggestive of desmoid fibromatosis (DF). This tumor was extirpated surgically (Fig. 2A), measuring 36 × 33 × 17 cm and weighing 13.4 kg. Histologically (Fig. 2B–D), it infiltrated the normal pancreas and expressed nuclear β-catenin.1Bhattacharya B. Dilworth H.P. Iacobuzio-Donahue C. et al.Nuclear beta-catenin expression distinguishes deep fibromatosis from other benign and malignant fibroblastic and myofibroblastic lesions.Am J Surg Pathol. 2005; 29: 653-659Crossref PubMed Scopus (249) Google Scholar Postoperatively, colonoscopy found no polyps. So far, she has been tumor-free for 12 months.Figure 2(A) Cut surface of the resected DF showed a glistening trabecular appearance, and appeared whitish gray. There was no hemorrhage and necrosis. (B) Hematoxylin and eosin staining of specimen sections disclosed hypocellular neoplasm along with normal pancreatic tissues (open arrowheads) in abundant collagenous stroma. (C) In a magnified view, spindle-shaped tumor cells, arranged in well-defined fascicles, exhibited bland nuclear morphology as evidenced by the absence of nuclear hyperchromasia and atypia. (D) Immunohistochemical staining demonstrated the nuclear localization of β-catenin (open arrows) in spindle-shaped tumor cells. The nuclear counterstaining also showed fine chromatin and inconspicuous nucleoli of the tumor cell nuclei.View Large Image Figure ViewerDownload Hi-res image Download (PPT) DF is characterized by its clonally fibroblastic proliferation and locally infiltrative and aggressive growth,2Desmoid Tumor Working GroupThe management of desmoid tumours: a joint global consensus-based guideline approach for adult and paediatric patients.Eur J Cancer. 2020; 127: 96-107Abstract Full Text Full Text PDF PubMed Scopus (145) Google Scholar leading to a tendency of local recurrence following resection despite its inability to metastasize. Thus, it has a variable and often unpredictable clinical course. Intraabdominal DF was relatively rare but frequently occurred in familial adenomatous polyposis.3Church J. Xhaja X. LaGuardia L. O'Malley M. Burke C. Kalady M. Desmoids and genotype in familial adenomatous polyposis.Dis Colon Rectum. 2015; 58: 444-448Crossref PubMed Scopus (35) Google Scholar Patients tended to be asymptomatic until signs of DF mass effects or local invasion.4Xu B. Zhu L.H. Wu J.G. Wang X.F. Matro E. Ni J.J. Pancreatic solid cystic desmoid tumor: case report and literature review.World J Gastroenterol. 2013; 19: 8793-8798Crossref PubMed Scopus (25) Google Scholar Generally, active surveillance is the initial approach to DF. However, surgery remains the first-line treatment in the case of the limited surgical morbidities anticipated for symptomatic DF that grows rapidly,2Desmoid Tumor Working GroupThe management of desmoid tumours: a joint global consensus-based guideline approach for adult and paediatric patients.Eur J Cancer. 2020; 127: 96-107Abstract Full Text Full Text PDF PubMed Scopus (145) Google Scholar,5Orbach D. Brennan B. Bisogno G. et al.The EpSSG NRSTS 2005 treatment protocol for desmoid-type fibromatosis in children: an international prospective case series.Lancet Child Adolesc Health. 2017; 1: 284-292Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar as with this patient whose DF expanded on such an unprecedented scale but was considered operable based on radiographic studies. The DF therapeutic algorithm makes no distinction between adults2Desmoid Tumor Working GroupThe management of desmoid tumours: a joint global consensus-based guideline approach for adult and paediatric patients.Eur J Cancer. 2020; 127: 96-107Abstract Full Text Full Text PDF PubMed Scopus (145) Google Scholar and children.5Orbach D. Brennan B. Bisogno G. et al.The EpSSG NRSTS 2005 treatment protocol for desmoid-type fibromatosis in children: an international prospective case series.Lancet Child Adolesc Health. 2017; 1: 284-292Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar This work was supported by CMRPG3M0191 from Chang Gung Medical Foundation, Taiwan.