Unusual location for a pseudopapillary tumor
An unusual location for a solid pseudopapillary tumor
Solid pseudopapillary tumors ( SPT ) are rare exocrine pancreatic tumors which most normally occur in immature adult females. Extra pancreatic SPT have been described to originate from the retroperitoneum, liver, omentum and mesocolon. Given their low mitotic index complete surgical resection provides the best forecast.
We hereby show a instance of a SPT arising from the right hemi-diaphragm, of a immature female, without the presence of a pancreatic primary tumor. Our patient underwent an extended resection including the right lower lobe, stop and a section of the liver. Histological resection was a complete. 18 months following the initial surgery she represented with hurting and computed imaging confirmed return. She has survived 3 old ages post resection.
We discuss this instance and the typical presentation of SPTs and how this instance provided a diagnostic challenge given its location. We stress the importance in a complete resection without the breach of the tumor. We discuss the usage of chemo-radiotherapy in this instance and underscore the demand for farther research to better understand its function.
Keywords: Cancer ( Diaphragm ) , Diaphragm, Histology ( Pseudopapillary tumor ) , Tumour ( Diaphragm )
Solid pseudopapillary tumors ( SPT ) are tumours typically found in the pancreas of immature females [ 1 ] . They have been described in extra-pancreatic sites including the retroperitoneum, omentum, liver and mesocolon [ 2,3 ] . The faineant nature of these tumors favour surgical resection. We present a instance of a pseudopapillary tumor centred on the right hemi-diaphragm with extension into the right hemi-thorax and venters. We emphasize the surgical considerations and discuss follow up scheme and direction.
A 42 twelvemonth old female ex-smoker presented with right sided chest hurting. Computed tomographic ( CT ) scans and magnetic resonance imagination ( MRI ) revealed a monolithic lesion widening from the right lower lobe into the venters with suggested invasion of the right adrenal secretory organ and right lobe of the liver ( Figures 1 and 2 ) . Prior to resection a laparoscopy was performed to further visualise the extent of mass and to obtain biopsies. Histology was non converting nevertheless suggested a low-grade papillose tumor.
Due to the uncertainness and the low grade nature of the mass it was felt that chemotherapy would hold a hapless response and that a surgical resection would offer the best forecast. She therefore underwent surgery affecting an drawn-out postero-lateral and subcostal thoracotomy to take the right lower lobe, most of the right hemi-diaphragm, the right anatomical lobe of the liver and the right adrenal secretory organ. All seeable tumor was removed and though it was felt that the tumor did non straight occupy the liver and lung these farther resections were carried out to guarantee clearance.
Macroscopically the tumor was good circumscribed weighing 2400 g and mensurating 27 ten 17 ten 12 centimeter. The cut surface revealed a heterogenous tumor with soft yellow crumbly tissue and big countries of mortification with the occasional cysts. The tumor did non infiltrate the lung, skeletal musculus, liver or the adrenal secretory organ.
Microscopic scrutiny revealed proliferation of ill cohesive cells which contain unit of ammunition karyon and pantie cytol. Occasional cells contained hyaloid globules. An alveolar and papillose form was noted with countries of mortification. The lesion was sick defined and tumour cells were present in next lung parenchyma. The tumor was microscopically wholly excised.
Immunohistochemistry showed positiveness with CD99 ( mic2 ) and CD56 markers. Tumour cells remained negative with all the epithelial markers tested, synaptophysin, S100, HMB45, Melan A, Desmin, SMA, Oestrogen receptor and Lipo-Lutin receptor markers. Beta catenin immunostaining showed preserved membranous look with no grounds of atomic translocation. By contrast, E-cadherin immunostaining showed loss of membranous look in 100 % of tumour cells. Ki67 immunostaining showed positive atomic staining in about 10 % of the tumor cells.
Overall visual aspects were so ( despite deficiency of beta catenin altered look ) extremely implicative of a solid pseudopapillary tumor centred on the right hemi-diaphragm. Importantly there was no ectopic pancreatic tissue seen. Histology suggested the tumor was to the full resected hence accessory therapy was non offered.
Eighteen months subsequently she represented with thorax hurting and CT scan and biopsy showed perennial disease with a similar histopathological profile. The CT scan suggested multiple focal point of return at around the chest wall. An extrapleural pneumonectomy was considered nevertheless this would non be healing and would transport an intolerably high morbidity and mortality. Due to the low mitotic index and low Ki-67 this tumor was faineant and was anticipated to non react to chemotherapy. The patient did undergo chemotherapy and radiation therapy for hurting. As expected she had a hapless response to chemotherapy nevertheless is alive 3 old ages post resection.
We have here presented the instance of a monolithic extra-pancreatic pseudopapillary tumor. Pseudopapillary tumors are rare lesions of the pancreas. Of all exocrine pancreatic tumors they account merely for 1-2 % . Greater than 90 % of instances are in immature females ( 4 ) . There have been few instances reported of extra-pancreatic pseudopapillary tumors nevertheless many of these were felt to be derived from ectopic pancreatic tissue ( 3, 5 ) . The sites described, other than the pancreas are ; the mesocolon, liver, retroperitoneum and greater omentum.
These tumors normally present with abdominal hurting or associated symptoms and marks of compaction. As in our instance serum tumor markers are typically negative. MRI is superior to CT due to their varying tissue features such as cystic constituents, bleeding, mortification and the presence of a capsule. Immunohistochemistry is priceless as it is typically positive for vimentin and anti-trypsin whilst being negative for trypsin and chymotrypsin. The CD99 positiveness and loss of E cadherin look a pseudopapillary tumor remains the most likely diagnosing. Differential diagnosings include neuroendocrine tumors, sarcomas ( EWS/ FLI1 Type 1 and 3 ) , vascular tumor ( CD34 and CD31 ) and melanoma ( S110, HMB45 and melan A ) . In our instance these other derived function diagnosings were excluded by the immunostaining of the markers listed. Give its unusual location, centrally focused on the right hemi-diaphragm, it has been hard to corroborate whether this is ectopic tissue, a metastatic sedimentation or an unusual presentation of a primary diaphragmatic tumor. As antecedently mentioned imaging did non uncover another primary focal point nor did histology suggest ectopic pancreatic tissue.
As these SPTs are rare and infrequently described in literature we have looked to the forecast of pancreatic pseudopapillary tumors which are normally good following extremist resection. This is due to the good encapsulated nature and the low class malignant potency of the tumor type. A five-year endurance rate of 97 % has been reported [ 6 ] . Local return rate of pancreatic pseudopapillary tumors have been reported at 6.2 % while distant metastasis occurs in 15 % of instances and nowadayss following a disease-free interval of 8.5 old ages [ 7,8 ] . In our instance return occurred much sooner than anticipated nevertheless there are illustrations of tumors with low mitotic index that demonstrate an aggressive nature such as: neuroendocrine tumors of the GI piece of land or lungs, GI stromal tumors ( GISTs ) and liposarcomas [ 9 ] . Currently no histological markers exist to assist foretell the aggressive nature or forecast. The distribution of the chest wall metastasis in this instance is similar in theory to the transcoelomic spread of pseudopapillary tumors. This early and local return could be explained by a possible breach of the tumor wall. Such breach is a known hapless predictive marker in GISTs [ 9 ] . As most of these types of tumors are to the full resected accessory chemotherapy or radiation therapy is non offered. Due to this ground the function of such therapy is yet to be defined. As these tumors have a low Ki67 index, chemotherapy was hence felt to hold a limited function nevertheless this was offered as our patient was acute to try any avenue of intervention.
In decision, this is a instance of an unusual location for an extra-pancreatic pseudopapillary tumor. In maintaining with pancreatic pseudopapillary tumor this instance was in a immature female. As with those that arise from the pancreas this tumor was good encapsulated and we feel the best direction option is for extremist surgical resection. We stress the demand to guarantee breach of the tumor does non happen. Due to the low grade nature of these tumors return is reported as rare and as in our instance occurred at 18 months. For this ground we suggest long term follow up with a low threshold to reiterate imaging. Further work demands to be carried out to specify the function of neoadjuvant or accessory chemo-radiotherapy in pseudopapillary tumors.
Figure 1. Transverse computed tomographic scan at the degree of the 8Thursdaythoracic vertebra. This shows the important tenancy of the thoracic pit by the diaphragmatic mass.
Figure 2. Coronal magnetic resonance image demoing the tenancy of the thoracic and abdominal pit by the diaphragmatic mass and its suggested engagement of the right kidney.