Cystic Metastasis of the Pancreas Indicating Relapse of Merkel Cell Carcinoma

Metastatic Merkel Cell Carcinoma of the Pancreas Mimicking Primary Pancreatic Endocrine Tumor Diagnosed by Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology

“…16 It has a penchant for local recurrence and distant metastasis to various sites, including regional lymph nodes, distant skin, lung, liver, testis and other rare organs such as pancreas. 6,[8][9][10] Our case represents the fifth reported metastatic pancreatic MCC and the first to be diagnosed by EUS-FNA cytology. The 4 previously reported cases were all diagnosed by histologic examination of pancreatic resection.…”

“…There are only 4 previous cases of MCC metastatic to the pancreas reported in the English-language literature. 6,[8][9][10] To the best of our knowledge, our case represents the first metastatic pancreatic MCC diagnosed by EUS-FNA cytology. …”

The diagnostic utility of Merkel cell polyomavirus immunohistochemistry in a fine needle aspirate of metastatic Merkel cell carcinoma of unknown primary to the pancreas

“…23 However, metastases to the pancreas are exceedingly rare; only 19 cases have been reported in the literature. [7][8][9][10][11][12][13][14][15][16][17][18][19] In these cases, the pancreas metastases were almost always preceded by nodal recurrence of primary MCCs or concomitant extra-pancreatic metastases.…”

“…[4][5][6] Pancreatic involvement by MCC is rare with 19 reported cases in the literature. [7][8][9][10][11][12][13][14][15][16][17][18][19] To date, only 8 cases have been diagnosed by endoscopic ultrasound-guided fine-needle aspiration cytology (EUS-FNA). 8,18,19 We report a case of MCC from an unknown primary manifesting as an axillary mass and a pancreatic metastasis.…”

Merkel Cell Carcinoma of the Gluteal Region with Ipsilateral Metastasis into the Pancreatic Graft of a Patient after Combined Kidney-Pancreas Transplantation

“…If MCC is confirmed, subsequent therapeutic measures should be sufficiently intensive and should not be influenced by effortstopreservethefunctionofthetransplantedgraft.Inour patient,theproximityofthetumourtothegraftandeffortsto preserve the pancreatic graft function influenced the initial decision of the oncologist to contraindicate adjuvant radiotherapy. The literature contains several mentions of MCC metastases into the autologous pancreas [37][38][39][40], but to our knowledge,wepresentthefirstcaseofMCCassociatedwith metastaticinvolvementofthetransplantedpancreas,leading eventuallytoitsdestructionandfailure.Ourcasealsodocumentsthehighaggressivenessofthetumourandtheineffectivenessofimmunosuppressivetherapyreductionandconversiontosirolimusinthistypeoftumour.…”