Shatrughan Prasad Sah

AIMS: Digital pathology (DP) offers advantages over glass slide microscopy (GS), but data demonstrating a statistically valid equivalent (i.e. non-inferior) performance of DP against GS are required to permit its use in diagnosis. The aim of this study is to provide evidence of non-inferiority. METHODS AND RESULTS: Seventeen pathologists re-reported 3017 cases by DP. Of these, 1009 were re-reported by the same pathologist, and 2008 by a different pathologist. Re-examination of 10 138 scanned slides (2.22 terabytes) produced 72 variances between GS and DP reports, including 21 clinically significant variances. Ground truth lay with GS in 12 cases and with DP in nine cases. These results are within the 95% confidence interval for existing intraobserver and interobserver variability, proving that DP is non-inferior to GS. In three cases, the digital platform was deemed to be responsible for the variance, including a gastric biopsy, where Helicobacter pylori only became visible on slides scanned at the ×60 setting, and a bronchial biopsy and penile biopsy, where dysplasia was reported on DP but was not present on GS. CONCLUSIONS: This is one of the largest studies proving that DP is equivalent to GS for the diagnosis of histopathology specimens. Error rates are similar in both platforms, although some problems e.g. detection of bacteria, are predictable.

Adenocarcinomas exhibiting gastric differentiation represent a recently described and uncommon subtype of non-human papillomavirus (HPV)-related cervical adenocarcinoma. They comprise a spectrum from a well-differentiated variant (adenoma malignum/mucinous variant of minimal deviation adenocarcinoma) to a more poorly differentiated overtly malignant form, generally referred to as gastric-type adenocarcinoma. Rarely, such tumors have also been described as primary vaginal neoplasms. Gastric-type adenocarcinomas exhibit considerable morphologic overlap with adenocarcinomas originating outside the female genital tract, especially mucinous adenocarcinomas arising in the pancreas and biliary tract. Moreover, they often metastasize to unusual sites, such as the ovary and peritoneum/omentum, where they can be mistaken for metastatic adenocarcinomas from other, nongynecologic sites. There is little information regarding the immunophenotype of gastric-type adenocarcinomas, and knowledge of this is important to aid in the distinction from other adenocarcinomas. In this study, we undertook a detailed immunohistochemical analysis of a large series of cervical (n=45) and vaginal (n=2) gastric-type adenocarcinomas. Markers included were cytokeratin (CK)7, CK20, CDX2, carcinoembryonic antigen, CA125, CA19.9, p16, estrogen receptor, progesterone receptor, MUC6, PAX8, PAX2, p53, hepatocyte nuclear factor 1 beta, carbonic anhydrase IX, human epidermal receptor 2 (HER2), and mismatch repair (MMR) proteins. All markers were classified as negative, focal (<50% of tumor cells positive), or diffuse (≥50% tumor cells positive) except for p53 (classified as "wild-type" or "mutation-type"), HER2 (scored using the College of American Pathologists guidelines for gastric carcinomas), and MMR proteins (categorized as retained or lost). There was positive staining with CK7 (47/47-45 diffuse, 2 focal), MUC6 (17/21-6 diffuse, 11 focal), carcinoembryonic antigen (25/31-12 diffuse, 13 focal), carbonic anhydrase IX (20/24-8 diffuse, 12 focal), PAX8 (32/47-20 diffuse, 12 focal), CA125 (36/45-5 diffuse, 31 focal), CA19.9 (11/11-8 diffuse, 3 focal), hepatocyte nuclear factor 1 beta (13/14-12 diffuse, 1 focal), CDX2 (24/47-4 diffuse, 20 focal), CK20 (23/47-6 diffuse, 17 focal), and p16 (18/47-4 diffuse, 14 focal). Most cases were negative with estrogen receptor (29/31), progesterone receptor (10/11), PAX2 (18/19), and HER2 (25/26). p53 showed "wild-type" and "mutation-type" staining in 27 of 46 and 19 of 46 cases, respectively. MMR protein expression was retained in 19 of 20 cases with loss of MSH6 staining in 1 patient with Lynch syndrome. Molecular studies for HPV were undertaken in 2 tumors, which exhibited diffuse "block-type" immunoreactivity with p16, and both were negative. This is the first detailed immunohistochemical study of a large series of gastric-type adenocarcinomas of the lower female genital tract. Our results indicate immunophenotypic overlap with pancreaticobiliary adenocarcinomas but suggest that PAX8 immunoreactivity may be especially useful in distinguishing gastric-type adenocarcinomas from pancreaticobiliary and other nongynecologic adenocarcinomas, which are usually negative. Diffuse "block-type" p16 immunoreactivity in a cervical adenocarcinoma is not necessarily indicative of a high-risk HPV-associated tumor.

AIMS: To evaluate the diagnostic value of bone marrow aspirates, trephine biopsies (BMB), and flow cytometry (FC) in the assessment of bone marrow infiltration in chronic lymphoid disorders. METHODS: Investigations were carried out in 110 diagnostic and follow up specimens from B cell disorders, namely: chronic lymphocytic leukaemia (CLL; 65), non-Hodgkin's lymphoma (NHL; 39), and hairy cell leukaemia (HCL; 6). A selected panel of monoclonal antibodies was used both for FC and immunohistochemistry. RESULTS: In CLL there was agreement between the three investigations in 71% of samples and in 88% when only FC and BMB were compared. In nine of 65 samples, FC and BMB were positive, although the aspirate was reported as negative. Four BMB negative samples had minimal residual disease (MRD) detected by FC, whereas two samples were positive both on BMB and aspirate but showed no evidence of disease on FC. In NHL, there was agreement between the three investigations in 22 of 39 cases, and in 27 of 39 cases there was agreement between FC and BMB. In eight of 39 NHL cases, FC was negative but the BMB was either positive (five) or uncertain (three), whereas in three of 39, FC was positive but BMB was either negative (one) or uncertain (two). In three of five uncertain BMB, no clonal population was detected by the polymerase chain reaction, whereas in the remaining two cases the nodular aggregates disappeared on further sectioning. CONCLUSIONS: Both BMB and FC are better than bone marrow aspirates for the detection of infiltration in B cell disorders. FC might be slightly more sensitive than BMB to detect MRD in CLL, whereas BMB may be slightly better than FC in NHL.

BACKGROUND: The purpose of the present study was to determine modes of presentation of retinoblastoma and the association between proptosis with orbital extension and histopathologically detectable optic nerve infiltration by the tumour. METHODS: Clinical records and histopathological reports of patients with retinoblastoma were studied retrospectively. The work was undertaken at a tertiary care hospital in eastern Nepal during the period from September 1995 to August 2002. RESULTS: A total of 43 patients with retinoblastoma were studied. Among them unilateral involvement was found in 39 patients (90.70%) and bilateral involvement in four patients (9.30%). The mean age of presentation was 3.04 +/- 1.80 years (95% confidence interval = 2.49-3.59). The commonest mode of presentation was proptosis with orbital extension in 19 eyes (40.42%) followed by leucokoria in 14 eyes (29.78%). Histopathological reports of 42 eyes (one patient died shortly after admission and did not have an autopsy) confirmed the diagnosis of retinoblastoma and revealed that the optic nerve cut section had been infiltrated in 18, of which 16 had the clinical finding of proptosis with orbital extension. This was statistically significant (relative risk = 21.33, P < 0.001). CONCLUSION: The commonest mode of presentation of retinoblastoma in Nepal is proptosis. Presence of proptosis with orbital extension is associated with optic nerve cut end infiltration by the tumour. The diagnosis or presentation of retinoblastoma in Nepal is delayed and there is tremendous scope for improvement in its management.

OBJECTIVE: To study the role of fine needle aspiration cytology (FNAC) and ancillary studies in the diagnosis of tubercular epididymitis or epididymo-orchitis. STUDY DESIGN: Forty patients with tubercular epididymitis or epididymoorchitis diagnosed on FNAC underwent a detailed clinical workup, imaging and microbiologic studies before being started on antitubercular treatment (ATT). One patient underwent orchiectomy. RESULTS: Clinically, the disease presented in patients of all ages usually as a scrotal swelling or rarely as a scrotal sinus (3) or abscess (3) or as part of disseminated tuberculosis (2). Three patients gave a history of previous tuberculosis. Scrotal sonography confirmed the involvement of the epididymis, testis or spermatic cord in each case. FNAC was diagnostic in 27 aspirates (epithelioid cell granulomas with caseation) but nondiagnostic in the rest. Tubercular etiology was confirmed directly by detection of acid-fast bacilli (AFB) on FNA smears in 24 (60%) patients and urine samples in 11 and indirectly in 9 patients with negative AFB by using a combination of a positive Mantoux test (5 of 9), presence of caseating granulomas on FNA smears (7 of 9) and therapeutic response to ATT (9 of 9). CONCLUSION: FNA as a minimally invasive technique plays a prime role in the diagnosis of tubercular epididymitis and epididymoorchitis. It provides adequate material for cytologic and microbiologic examination and helps to avoid unnecesary orchiectomy.