Discussion:
fibromatoses (Desmoid-type) tumour is rare benign fibrous tumours
account approximately for 0.03% of all neoplasms in USA. Pancreas is
even more rarely reported subset with approximately 5% of all
desmoid-type fibromatoses [8–10].
The unique aggressive local invasion is characteristic of DT that render
the tumour unresectacble or with high local recurrence, but not unknown
to case distant metastases as thesis a benign tumour.
These tumours are more commonly present in young adolescent patient
[5, 11]. intraabdominally DT, occurs in around 8% of all DT and
more likely to be in adults than paediatric age groups, affecting any
part of the gastrointestinal and genitourinary tracts [12] the
comments origin of intraabdominal DT are of mesenteric or retro
peritoneum connective tissue. the pancreatic origin DT remain an
extremely rare subset of DTs. The English literature from the 1980s
report 27 pancreatic DT, therefor our case is the 28th case [1, 2, 4,
5, 10, 13–18].
clinical presentation of intraabdominal DTs is none specific in symptoms
and signs. In general symptoms and signs are related anatomical location
of the DT mass and/ or invasion of nearby structures causing bowel
obstruction, ischemia, fistulas, gastrointestinal bleeding or
perforation an ureteric obstruction. Pancreatic-origin DT behave like
pancreatic cancer in presentation as asymptomatic mass or with
nonspecific mild epigastric pain or painless jaundice if the tumor
location is in the head or the uncinate process. [1, 5]. Our patient
presented with mild to moderated abdominal pain associated with nausea,
weight loss and splenic mass for investigation. and possible
complications [19].
Imagining is valuable especially CT scans and/ or MRI to determine
invasiveness, aid in biopsy approach and to assess resectability but not
diagnostic [1, 4, 5].
In FNA histopathology as in our case the presence of spindle cells is
common but not pathognomonic for DT. The
Immunohistochemistry feature of
intraabdominal DT characterize by a positive vimentin and β-catenin and
as importantly negative for S100, CD34, and CD117 for the SMA [5].
Our case confirmed typical DT Immunohistochemistry criteria (Fig 3).
the immunohistochemistry is the mainstay of confirming DT with
characteristic negative S100 protein, in most of the case with rare
exceptions [20]. the presence of positive nuclear β-catenin staining
is important diagnostic feature present in around 80% of the cases but
not specific only for this tumour.
Unequally DT can be further confirmed by demonstrating mutations of
β-catenin gene in exon 3 which is positive in 85% of the case
[11,13].
Favourable prognosis reported by Jia et al. with overall survival of
100% and disease-free survival of more than 80% [5]. however,
accurate prognosis is not well reported and in sporadic cases reported
high postoperative recurrence rate around 19-77%, especially when
associated with Gardner syndrome and FAP with recurrence rate up to 90%
[5, 16].
To date there we lack consensus or guidelines for management of DT. The
first-line management of DT was and remain wide free margin complete
resection (radical resection) given the aggressive nature and excessive
local invasive behaviour of the tumour with the guidance of frozen
section support considering the locally invasive behaviour of this
tumour. Observation without surgical resection also called wait-and-see
approach mainly in static tumour were recommended by some expert to avid
morbidity and the possible high recurrence associated with surgery
especially in asymptomatic cases with mild manageable symptoms.
As a possible second line of management and specifically in case of
high-risk patients for surgical intervention or in advance stages an
adjuvant systemic chemotherapy based mostly in combination of
methotrexate, vinblastine, doxorubicin, and dacarbazine and /or radio-
or molecular target therapy as Tamoxifen. The use of COX2 inhibitors
e.g., NSAID and celecoxib demonstrated promising successes in some
studies, however, the mechanism by which it achieves regression is not
clearly reported [4, 5, 16, 19].