Immunohistochemistry of mammary Paget's disease. Cytokeratin 7, GATA3, and HER2 are sensitive markers.

OBJECTIVES: To investigate the expression of various immunohistochemical markers in Mammary Paget's disease (MPD) and MPD-associated breast carcinoma and to evaluate their value in establishing the diagnosis. METHODS: This retrospective descriptive study was carried out at King Faisal Specialist Hospital and Research Center and King Khalid University Hospital, Riyadh, Saudi Arabia. All MPD cases reported between January 2010 and June 2016 were selected from the surgical pathology records.  Immunohistochemical staining was carried out for cytokeratin 7 (CK7), GATA-binding protein 3 (GATA3), human epidermal growth factor receptor 2 (HER2), and estrogen, and progesterone receptors. Results: Twenty-two cases of MPD and 20 cases of MPD-associated breast carcinoma were included. CK7 was positive in 95% (21/22) cases of MPD and in all (20/20) cases of associated breast carcinoma. Similarly, GATA3 was expressed in 95% cases of both MPD (21/22) and associated breast carcinoma (19/20). Human epidermal growth factor receptor 2 was also overexpressed in 90% cases of MPD (20/22) and associated breast carcinoma (18/20). Estrogen stained positive in 27% cases of MPD (6/22) and 30% of cases of associated breast carcinoma (6/20). Progesterone receptors was not positive in any case of MPD; however, it was seen positive in 25% cases of MPD-associated breast carcinoma (5/20). CONCLUSIONS: CK7, GATA3, and HER2 are widely expressed in MPD and MPD-associated breast carcinoma. These markers can be used for the immunohistochemical confirmation of MPD including CK7-negative cases.

Molecular subtyping of mammary Paget's disease using immunohistochemistry.

OBJECTIVE: To evaluate the molecular subtypes of Mammary Paget's disease (MPD) and the associated breast carcinomas. METHODS: This retrospective study was carried out at King Khalid University Hospital and King Faisal Specialist Hospital, Riyadh, Saudi Arabia. Data from MPD patient cases from January 2010 to June 2016 were reviewed. The molecular subtypes were determined based on estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) expression with immunohistochemical staining. The relative frequencies of the luminal A and B, HER2-enriched and basal-like molecular subtypes were calculated and compared for MPD and the associated breast carcinomas. Results: Among 22 patients with MPD, HER2-enriched was the most frequently occurring molecular subtype and was observed in 11 (50%) patients. Mammary Paget's disease was classified as basal-like in 5 (22.7%) patients, and luminal A and B were each detected in 3 (13.6%) patients. The molecular subtype of MPD corresponded with the subtype of the associated breast carcinoma in 18 out of 20 patients (90%). CONCLUSIONS: The HER2-enriched subtype is the most frequently occurring molecular subtype in MPD. The molecular subtype of the associated breast carcinoma is usually similar to that of MPD. The molecular subtypes vary between MPD associated breast carcinoma and overall breast carcinoma. The HER2-enriched subtype is the most frequently occurring subtype of MPD associated breast carcinoma, while luminal subtypes are more common in overall breast carcinoma.

Differential diagnosis between pancreatic neuroendocrine and solid pseudopapillary neoplasms on endoscopic ultrasound-guided fine-needle aspiration. An immunohistochemical study.

OBJECTIVES: To evaluate the role of applying a limited panel of immunohistochemical stains on the cellblock preparation from samples obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in the aim of differentiating solid pseudopapillary neoplasms (SPNs) from neuroendocrine tumors (NETs).  METHODS: We retrospectively retrieved all the EUS-FNAs of the pancreas that have a diagnosis of NET or SPN that were performed at 2 tertiary care hospitals in Riyadh, Kingdom of Saudi Arabia from May 2004 to December 2014. Diff-Quik, Papanicolaou, and Immunohistochemistry stains on cellblock preparations were performed.   RESULTS: Twenty cases were available (16 pancreatic neuroendocrine tumors (pNETs) and 4 SPNs). The pNETs were immunoreactive for synaptophysin, chromogranin A and CD56 while E-cadherin was diffusely to focally cytoplasmic positive. ß-catenin was negative or showed focal cytoplasmic immunoreactivity. In comparison, SPNs were positive for vimentin, CD10, CD-56, focally positive for progesterone receptors and synaptophysin, and revealed nuclear immunostaining for ß-catenin. They were negative for chromogranin A and E-cadherin.  CONCLUSION: Based on EUS-FNA samples, nuclear immunoreactivity for ß-catenin with loss of membranous immunostaining for E-Cadherin can potentially facilitate differentiating SPNs from pNETs.

Menetrier`s disease in a Saudi child.

Menetrier`s disease is a rare form of acquired gastropathy that presents mostly during adulthood, but is extremely rare in children. It is a clinicopathological diagnosis that typically presents with abdominal pain, vomiting, and edema secondary to hypoalbuminemia. Endoscopy usually shows giant gastric mucosal folds, and gastric biopsy shows foveolar hyperplasia and decreased oxyntic glands. Here, we describe a 5-year-old boy from Saudi Arabia with typical presentation of Menetrier`s disease and serological evidence of acute cytomegalovirus infection.

Fine needle aspiration cytology in the evaluation of lymphoid lesions: a retrospective study of the utility of flow cytometry in conjunction with morphology.

BACKGROUND AND OBJECTIVE: Fine needle aspiration (FNA) cytology, in conjunction with flow cytometry, is now widely used as a reliable and accurate method for the assessment of various lymphoid lesions, especially for lesions situated in odd locations where obtaining biopsy and monitoring for recurrence in previously diagnosed cases of lymphoma are difficult. The objective of this study was to determine the utility of FNA and immunophenotyping in the assessment of lymphoid lesions, and to find whether flow cytometry is more useful in the evaluation and subclassification of the small cell morphology group of lymphomas than in the large cell morphology group of lymphomas. DESIGN AND SETTING: Retrospective analysis of patients diagnosed with lymphoma over at a 5-year period. PATIENTS AND METHODS: All 175 FNA cases were followed carefully either clinically or histologically for at least 5 years. We compared the utility of flow cytometry in the diagnosis of small cell morphology lymphomas to large cell morphology lymphomas. RESULTS: Flow cytometry was performed on 72 of 175 (41%) of FNA specimens clinically suspicious of lymphoma. The excisional follow-up biopsy was obtained in 78 of 175 (44.5%) cases. Based on cytomorphologic evaluation, 82 cases (47%) were considered negative, 34 cases (19%) were considered atypical, 32 cases (18%) were positive for NHL-small cell morphology, 21 cases (12%) were positive for non-Hodgkin lymphoma (NHL)-large cell morphology, 3 cases (2%) were positive for NHL, and 3 cases (2%) were nondiagnostic. Immunophenotyping utilizing flow cytometry was the diagnostic parameter in 28 of 32 cases (88%) of the NHL-small cell morphology group and in 11 of 24 cases (46%) of the NHL-large cell morphology/Hodgkin lymphoma group. CONCLUSIONS: Immunophenotyping by flow cytometry is more essential for the accurate evaluation and classification of small cell morphology than large cell morphology lymphoid lesions in FNA cytology.