Clear cell lesions in pathology: Histomorphologic approach to diagnosis.

There has been remarkable progress in the field of surgical pathology; however, histomorphology has remained the most important and essential tool of the surgical pathologist in everyday practice till now. It is surprising that the hematoxylin-eosin (H and E) stain, introduced more than a century ago, has still remained the gold standard stain for histological examination and diagnosis of human diseases. Besides different findings or clues observed in histopathology sections like inclusions, granules, grooving, globules, halo, or clearing, which would enable the pathologist to provide a precise and accurate diagnosis; observation of clear cells is one of the important findings and clue for reporting. It may also sometimes lead to difficulties and delays in establishing the diagnosis. It can be focal or extensive and primary or rarely it may be secondary. Clear cell changes may be observed in many non-neoplastic, benign, or malignant tumors of diverse origin. Clear cell tumors contain a preponderance of clear cells. It can be seen in almost all the organs of human body and can be classified according to location or biological behavior. Commonly seen clear-cell tumors are usually malignant and common organs involved are female genital tract, urogenital tract, head and neck areas, central nervous system, skin, and rarely in bone and soft tissues. For approach to clear cell lesions, one has to decide if the change is artifactual, a mimic of clear cell tumors, or a clear cell tumor in reality. Once the mimics and artifactual/degenerative changes have been ruled out, a tumor either primarily of clear cell origin or showing secondary change has to be decided. The tumor next is to be diagnosed as benign/malignant and epithelial/mesenchymal based on morphology.

Differential expression of cyclin E, p63, and Ki-67 in gestational trophoblastic disease and its role in diagnosis and management: A prospective case-control study.

BACKGROUND: Gestational trophoblastic disease (GTD) constitutes a spectrum of tumors and tumor-like conditions, characterized by proliferation of pregnancy-associated trophoblastic tissue of progressive malignant potential. It is very difficult to differentiate these complex groups of lesions basing on histomorphology alone. Immunohistochemistry (IHC) with cyclin E, P63, and Ki-67 has a definite role in the identification of different trophoblasts and entities of GTD and also in the determination of biological behavior. AIMS: The aim of this study is to find the differential expression of cyclin E, p63, and Ki-67 in normal placenta, hydropic abortus (HA), and various entities of GTD. DESIGN AND SETTINGS: A prospective case-control study conducted in a government medical college. METHODS: Total 96 cases, divided into Group A (48 histologically confirmed cases of GTD) and Group B (controls comprising 8 HA and 40 normal placentas of different trimesters), were studied. The histological samples were subjected to IHC using cyclin E, Ki-67, and p63. STATISTICAL ANALYSIS: Results were analyzed using SPSS statistical method. RESULTS: Among the three immunomarkers used, Cyclin E and Ki-67 show statistically significant difference (P < 0.05) when compared between GTD and control groups, but it was insignificant for p63 (P = 0.369). Strong staining intensity of cyclin E and Ki-67 is seen in complete moles, choriocarcinoma, and placental site trophoblastic tumor. CONCLUSION: This study was done to evaluate the role of cell cycle regulatory proteins such as cyclin E and p63 and proliferation marker Ki-67 in the detection of various trophoblasts and differential diagnosis of the lesions associated with them.

Serous Tubal Carcinogenesis: The Recent Concept of Origin of Ovarian, Primary Peritoneal and Fallopian Tube High-Grade Serous Carcinoma.

Background: Pelvic (non-uterine) high-grade serous carcinomas (PHGSC) including ovarian, tubal and primary peritoneal serous carcinomas have increased death: incidence ratio due to presentation at advanced stage, rapid progression, poor prognosis and high morbidity. Ambiguity regarding their pathogenesis and lack of a proper screening method is the cause of their late detection and high fatality rate. This study was undertaken to assess the fallopian tube for the presence of precursor lesions in pelvic serous carcinoma. Methods: This was a prospective case-control study carried out in a tertiary care center. Consecutive specimens of 55 cases of pelvic high-grade serous carcinoma and 41 controls inclusive of 21 low-grade serous carcinoma, 10 benign adnexal masses and 10 normal adnexa were included in the study. Both side fallopian tubes in each case were subjected to histopathological examination and p53, Ki67 immunohistochemistry. Results: There were 55 cases of PHGSC comprising of 50 cases of ovarian HGSC, two cases of primary peritoneal carcinoma (PPC) and three cases of tubal carcinoma. Serous tubal intraepithelial carcinoma (STIC) was detected in 14 cases (28%), p53 signature in 13 cases (26%) and tubal intraepithelial lesion in transition in 10 cases (20%) of ovarian HGSC. One case (50%) of PPC and one (33%) case of tubal carcinoma revealed the presence of STIC. None of the controls exhibited any precursor lesion except ovarian low-grade serous carcinoma where p53 was detected in 20% of cases. Conclusion: This revelation concludes that fallopian tubes are the sites of precursors of PHGSC to a large extent. In the absence of a proper screening method of HGSC, prophylactic bilateral salpingectomy at hysterectomy for benign diseases can achieve ultimate goal of reduction in incidence of PHGSC.

Cytologic Interpretation of Melanotic Neuroectodermal Tumour of Infancy Involving Cranial Bones: Clue to Diagnosis.

Melanotic neuroectodermal tumour of infancy (MNTI) is a rare, benign but locally aggressive neoplasm of infants commonly affecting the maxilla. It can also involve other areas like skull, mandible, brain and epididymis. The tumour comprise of dual populations of cells like small, basophilic neuroblast like cells and large pigment laden epithelial cells arranged in tubular and pseudoglandular pattern. The proportion of two components varies and therefore the diagnosis can be difficult in absence of the large cells. We describe the cytologic, histologic and immunohistochemical findings in a case of MNTI involving left side orbit with frontal, temporal and parietal bones. The cytologic interpretation could be made due to the suggestive clinical and radiologic findings and detection of large epithelial pigmented cells on thorough searching. The neuroblast like cells was positive for Neuron specific enolase, large cells for HMB-45 and Pan CK. Both the cellular components were negative for desmin. This case report is presented due to its rarity and also to aid the surgical pathologists in diagnosis where the findings are not too straight forward.

Peritoneal Keratin Granuloma Masquerading as Disseminated Carcinoma.

Peritoneal keratin granuloma is a rare lesion included under granulomatous lesions of the peritoneum. It can be of infectious and non-infectious etiology. The lesion presents as a large intra-abdominal necrotic mass often misinterpreted clinically as a disseminated carcinoma. We report a case of peritoneal keratin granuloma in a 50-year-old male following peritonitis. Histomorphology revealed laminated keratin deposits with giant cell reaction. Follow-up data of this granuloma suggests that it has no prognostic significance.