PMC4748796_01
Histology and immunohistochemistry. a HE staining (x100) of the primary tumor sample leading to the diagnosis of an intestinal type. b HE staining (x200) of the resected pulmonary metastasis showing a slightly better morphological differentiation than the primary tumor. c Immunohistochemical staining for CK7 (x400) of the primary sample shows a strong positive response of the tumor cells. d Immunohistochemical staining for CDX2 (x400) of the primary sample depicts a mostly negative result with very small foci of positive staining.
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F1
Conventional histomorphological analysis classified the tumor to be of the intestinal type (fig. 1a). Overall, the histological characteristics of the metastasis matched those of the primary tumor sample (fig. 1b). Given the extraordinary response to a typical therapy for metastatic pancreatic ductal adenocarcinoma, we retrospectively performed further immunohistochemical analyses of the primary tumor samples (fig. 1c, d) and the resected pulmonary metastatic lesion (not shown).
Course of CA 19-9 level. PD = Progressive disease; nab-paclitaxel = nanoparticle albumin-bound paclitaxel.
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F2
At the first follow-up visit 2 months after completion of adjuvant therapy, the level of the tumor marker CA 19-9 was slightly increased (fig. 2). A positron emission tomography-CT showed a number of small fluorodeoxyglucose-negative nodules in the lower lobe of the right lung. The level of CA 19-9 had increased slightly (fig. 2). The CA 19-9 level had risen to 2,992 U/ml (fig. 2).
Initial contrast-enhanced CT of the liver did not display any signs of liver metastases (a). Follow-up CT 15 weeks later readily reveals two liver metastases in segments IVa and VII (bold arrows in b). Therapy with nanoparticle albumin-bound paclitaxel and gemcitabine was initiated. Follow-up CT 13 weeks thereafter demonstrates reduction in size of both liver metastases (c). At further follow-up CT at 17 weeks after initiation of nanoparticle albumin-bound paclitaxel/gemcitabine only residual findings of the former liver metastases are visualized (transparent arrows in d).
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F3
The CT scan showed an increase in the preexisting pulmonary metastatic spread and new liver metastases (fig. 3). After 6 months, treatment had resulted in a stable partial remission as documented by the regression of pulmonary metastases and liver metastases (fig. 3), and normalization of the CA 19-9 level (fig. 2).