Differential expression of CK7, CK20, CDX2 in intestinal and pancreatobiliary types of preriampullary carcinoma.

CONTEXT: Incidence of periampullary carcinoma is low, approximately 0.5-2% of all gastrointestinal malignancies. Histologic subtyping has a prognostic bearing. The purpose of this study is to differentiate periampullary carcinomas based on immunohistochemistry (IHC) by using cytokeratin 7 (CK7), cytokeratin 20 (CK20), caudal type homeobox 2 (CDX2). AIMS: To analyze the usefulness of IHC as single/panel of markers that included CK7, CK20, and CDX2. SETTINGS AND DESIGN: This was a prospective study done from January 2017 to September 2018. SUBJECTS AND METHODS: A total 50 pancreaticoduodenectomy specimens were evaluated and classified as intestinal (INT) and pancreaticobiliary (PB) types based on their morphological and immunohistochemical features, respectively. The morphologic subtypes, expression of IHC markers were correlated with different histologic parameters. STATISTICAL ANALYSIS: Chi-square test was used to study the association between different IHC markers with histologic parameters. Probability (P) values <0.05 were regarded as statistically significant. RESULTS: The expression of CK7, CK20, CDX2 were studied in 50 cases to classify them as INT and pancreatobiliary subtypes. CK7 has high sensitivity (88.2%), CDX2 has high specificity (96.4%), CK20+/CDX2+ has both high sensitivity (94.2 percent) and specificity (89.2 percent) in differentiating INT from pancreatobiliary subtypes. The morphologic subtypes showed correlation with two variables (tumor grade, pathologic T stage). CK20 and CK20/CDX2 expression showed a positive correlation with tumor grade, pathologic T staging, and lymphovascular invasion. CONCLUSIONS: In conclusion, morphological classification can significantly discriminate histologic types, IHC plays a moderate role. However, the combined expression of CK20 and CDX2 is helpful in subtyping.

Solid and cystic papillary neoplasm of pancreas: A clinic-pathological and immunohistochemical study: A tertiary care center experience.

BACKGROUND: Solid pseudopapillary tumor of the pancreas (SPT) is a rare tumor of low malignant potential, mostly described in young women. MATERIALS AND METHODS: In this retrospective study from January 2000 - December 2010, there were 50 pancreatic tumors. In this period, four SPTs were encountered, which were analyzed with respect to clinical, imaging, histopathological, and immunohistochemical findings. RESULTS: There was a female preponderance with mean age of 22.2 years. Two of the tumors were located in head of the pancreas and two in the body and tail region. On imaging, majority were large cystic tumors. Histopathologically, they exhibited extensive necrosis and presence of pseudo papillae in viable areas. Immunohistochemically, they were positive for alpha-1-anti-trypsin, alpha-1-anti-chymotrypsin, vimentin, CD10, and CD99. Progesterone receptor and p53 exhibited mild positivity in all of the four cases, whereas neuron specific enolase (NSE), synaptophysin, and chromogranin showed focal positivity in one case. CONCLUSION: Despite its non-specific clinical, imaging, and even immunohistochemical features, characteristic gross and microscopic findings provide reliable diagnosis of SPTs.

Myxoid chondrosarcoma of sphenoid bone.

The myxoid variant of chondrosarcoma is usually seen in soft tissues where it is known as chordoid sarcoma or parachordoma. Rarely, it involves bone and when it does, cranial bones are the preferred location. This tumor is frequently amalgamated with the chondroid variant of chordoma, especially when the lesion occurs in the sphenoid bone/spheno-occipital region, because of their similar clinical presentations, anatomical locations, radiological findings, and mistaken histopathological features. It is essential to distinguish myxoid chondrosarcoma from the chondroid variant of chordoma, because of the different treatment protocol and prognostic importance. We present such a location-based diagnostic dilemma, solved successfully with ancillary immunohistochemistry.

Cervical ectopic thymus masquerading as metastatic thyroid papillary carcinoma.

Cervical ectopic thymus (CET), a common embryological anomaly detected incidentally at autopsy, is rarely described in clinical patients. Furthermore, aberrant cervical thymic tissue is an infrequently reported cause of paediatric neck masses. We report a 12-year-old female presenting with multinodular thyroid swelling since seven years of age. FNAC revealed adenomatous goitre with suspicious cystic papillary neoplastic foci, for which she underwent total thyroidectomy along with excision of a nodular swelling near the lower pole of the right thyroid lobe which was per-operatively suspected to be a lymph node. Histopathological examination revealed a follicular variant papillary carcinoma of the thyroid with background thyroiditis, and a nodule of ectopic thymic tissue. Though the presence of CET is rare, one should be aware of this entity, especially in children because it may be confused with lymph node metastasis which may lead to morbid radical neck dissection.