Chen, Longwen

Abnormalities of the gastrointestinal (GI) tract due to drugs (AGIDs) are numerous and have significant impact. The aim of this narrative review is to help the practicing surgical pathologist recognize selected AGIDs. The adverse drug effects presented were chosen with an emphasis on recent and significant pathological and clinical contributions. The selection was based on a thorough review of the PUBMED-based literature and on the authors’ opinions and experience. In the first part of the review, diagnostic abnormalities due to crystals (eg, iron, biphosphonates, nonsystemic drugs), mitosis arresting drugs (colchicine, taxanes), and biological agents, especially ipilimumab, are discussed. Some AGIDs’ histopathologic features can be easily recognized. It is however the clinical correlation that in many cases of AGIDs will provide the necessary support for a drug effect diagnosis. The identification of AGIDs requires heightened awareness of the medical team in which close collaboration of pathologists and clinicians cannot be overemphasized.

Inflammatory cap polyposis (ICP) is a rare nonneoplastic polyposis of the colon of unknown etiology that can be confused with prolapse-induced polyps and hyperplastic polyposis. We contribute a case of ICP from a 59-year-old woman who was affected by severe constipation and hematochezia. Numerous sessile and semipedunculated polyps were found in the colon, all with cap of whitish fibrin. Histology revealed erosion of the surface, superficial dilated crypts filled with mucoid inflammatory exudate, and minimal crypt serration, all findings typical of ICP. Only the largest polyps had smooth muscle in the mucosa. Ki-67 showed modest expansion and irregular distribution of the crypts proliferative areas. Low-degree positivity for p16, similar to that of hyperplastic polyps, was found. CK20 was expressed as in normal mucosa. Distinguishing between ICP and other polyposis is important because of difference in management.

BACKGROUNDThe cytological diagnosis of malignant mesothelioma (MM) on serous effusion is challenging due to significant morphologic overlap with reactive mesothelial cells and adenocarcinoma. One of the morphologic features of MM in effusion cytology, small orangiophilic squamous‐like cells (SOSLC), has received little attention. To the best of the authors' knowledge, the current study is the first to assess the sensitivity and specificity of SOSLC in serous effusion specimens from histology‐proven MM cases along with those of reactive mesothelial and adenocarcinoma cases.METHODSA total of 130 cases of pleural (86 cases) and peritoneal (44 cases) effusion cytology cases (30 with histology‐proven MM, 41 with adenocarcinoma, and 59 with reactive mesothelial cells) were studied. The presence or absence of SOSLC was recorded in each case.RESULTSThe cytological diagnoses of the 30 histology‐proven MM cases included 1) atypical mesothelial cells, favor reactive (4 cases); 2) atypical mesothelial cells, suspicious for or cannot exclude mesothelioma (18 cases); and 3) positive for MM (8 cases). SOSLC were found in 10 of the 30 MM effusion cases (33.3%), 1 of the 41 adenocarcinoma cases (2.4%), and 5 of the 59 reactive mesothelial cell cases (8.5%). SOSLC were more likely to be present in MM effusions compared with either adenocarcinoma (P < .0001) or reactive mesothelial cell (P < .02) effusions. All 10 cases of MM with SOSLC were from pleural fluids. One case of peritoneal serous adenocarcinoma had SOSLC and 5 cases of reactive mesothelial cells in peritoneal fluid were found to have SOSLC.CONCLUSIONSAlthough not sensitive, the presence of SOSLC is quite specific for MM in pleural fluid cytology specimens. Finding this morphological feature in pleural fluid should alert the pathologist to a possible diagnosis of MM.Cancer (Cancer Cytopathol) 2014;122:70–75. © 2013 American Cancer Society.

A 66-year-old male patient presented with nausea, abdominal pain, occasional rectal bleeding, progressive dysgeusia, onicodystrophy, and alopecia. Endoscopic exam and biopsies revealed severe atrophy and diffuse marked edema of mucosa of stomach and duodenum. No evidence of polyps was found in any portion of the gastrointestinal tract. The diagnosis of Cronkhite–Canada syndrome (CCS) was rendered. The patient symptoms resolved completely after initiation of steroid treatment. This additional case of CCS illustrates how the diagnosis of CCS does not require the presence of polyps but is defined by the appreciation of the diffuse marked edema and atrophy of the gastrointestinal mucosa.

Bronchial mucoepidermoid carcinoma (MEC) is rare, comprising about 0.2% of primary lung tumors. Endobronchial ultrasound (EBUS) guided fine‐needle aspiration (FNA) cytology is an integral tool in the diagnosis and staging of malignant lung tumors. Rapid on‐site evaluation (ROSE) has been proven useful as a guide for assessing the adequacy and accuracy of the FNA samples. Therefore, comprehensive knowledge of diagnostic cytomorphologic findings of MEC is critical for ROSE.We reported a 46‐year‐old woman with 6 weeks of cough productive of yellow sputum that did not improve on antibiotics. A chest CT demonstrated a well‐circumscribed nodule in the right lower lobe bronchus that extended into the lung parenchyma. EBUS‐guided FNA was performed to obtain diagnostic materials. The ROSE of cytology specimen revealed numerous tight clusters of cells with well‐defined, but scant cytoplasm. These cells were relatively small and bland with high N/C ratio, resembling benign ductal cells. Neither cilia nor intranuclear inclusions were noted. Focal extracellular metachromatic mucinous materials were also noted. A preliminary diagnosis of “low‐grade epithelial neoplasm, favor low grade MEC” was rendered. The definitive diagnosis was confirmed by both cytology and core biopsy.EBUS‐guided FNA cytology can be a reliable method for the diagnosis of bronchial low grade MEC. The cyto‐morphology of ROSE can indicate the diagnosis of low grade MEC and direct the appropriate follow‐up triage of the specimen.Diagn. Cytopathol. 2013;41:1096–1099. © 2012 Wiley Periodicals, Inc.