Diagnosis of Mucormycosis Using Frozen Section, Histopathology, Culture, and Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) Techniques: A Comparative Study.

Mucormycosis usually occurs in immunocompromised patients or those with uncontrolled diabetes. Along the third wave of SARS-CoV-2, an associated angioinvasive opportunistic infection with Mucor, a life-threatening fungal infection, was rampant and emerging. With an increase in the usage of steroids in the COVID scenario, the rate of mucormycosis did take a rapid and alarming increase in King Edward Memorial Hospital, Pune, India. Any delay in the diagnosis and management of the disease was life-threatening. The most conventional methods to diagnose mucormycosis are microbiological culture and histopathology of the tissue. The microbiological culture method plays an important role in the diagnosis of mucormycosis. However, the technique is labour-intensive, taking seven to eight days. Histopathology leads to false-negative reports if the tissue is not biopsied from representative sites. On the other hand, molecular methods are rapid, reliable, and applicable to different body samples, such as tissue, paraffin-embedded tissue blocks, plasma, and urine. We aimed to use a reverse transcriptase polymerase chain reaction (RT-PCR) method to detect Mucor in plasma samples. Due to a lack of availability of fresh samples, nucleic acid was extracted from the tissue sections of 69 cases diagnosed as Mucor by histopathology. These samples were subjected to RT-PCR using the MucorGenius kit (Pathonostics, Maastricht, Netherlands). A total of 57 tissue samples were sent for culture, and 49% of our cases were positive by culture and equally by RT-PCR. There was 80% sensitivity and 76% specificity between culture and PCR techniques. However, the use of blood/plasma for RT-PCR for early diagnosis of mucormycosis will be the method of choice.

A Case Report on CNS Hemophagocytic Lymphohistiocytosis in an Infant With Dengue Hemorrhagic Fever.

India is an endemic country for dengue. The incidence of hemophagocytic lymphohistiocytosis (HLH) with dengue in children has been well-reported. However, central nervous system (CNS) HLH associated with dengue has not been described in the literature yet. We hereby report a novel case of CNS HLH triggered by dengue infection. An eight-month-old, well-grown male infant with uneventful antenatal, perinatal, and neonatal history was admitted with a history of febrile illness associated with cough, cold, vomiting, and loose motions and one episode of hematochezia and hepatosplenomegaly on examination. Investigations revealed bi-cytopenia, hyper-ferritinemia, deranged coagulation profile, liver function test, and hypo-fibrinogenemia. Dengue non-structural protein 1 ( NS1) antigen was positive. The child was given dexamethasone and continued supportive care with a diagnosis of dengue shock syndrome. The child showed an overall transient improvement, however, he had rebound fever followed by right focal convulsion on Day 9 of steroids. MRI brain revealed areas of diffusion-restricted embolic infarcts with diffuse leptomeningeal enhancement and mild cerebral edema, and CSF showed a total leukocyte count of 80 cells with 75% lymphocytic picture, histiocytes with hemophagocytosis, confirmatory of CNS HLH. Intrathecal methotrexate, hydrocortisone, and intravenous (IV) etoposide were started. However, the child succumbed to his illness. CNS involvement in dengue-triggered HLH needs to be suspected despite subtle neurological signs and aggressively managed following a multi-departmental approach to ensure the best clinical and neuro-developmental outcomes.

Strong Coexpression of Transcription Factors PU.1 and Oct-2 in Rosai-Dorfman Disease.

OBJECTIVES: Rosai-Dorfman disease (RDD) is a rare disorder characterized by the accumulation of large S100 protein-positive histiocytes that typically exhibit emperipolesis. The recently reported expression of Oct-2 in RDD histiocytes led us to explore whether PU.1, a transcription factor that is required for monocyte and B-cell development, could similarly function as a diagnostic marker in RDD. METHODS: We evaluated the expression of PU.1 and Oct-2 using immunohistochemistry in 19 patients diagnosed with RDD involving nodal, extranodal, and cutaneous sites. RESULTS: Both PU.1 and Oct-2 were positive in all cases studied, with a strong intensity of staining in 84% of cases in which more than 50% of the lesional cells were positive. In three patients, both markers showed weak to moderate intensity of staining. Two patients had concomitant RDD and Langerhans cell histiocytosis in which PU.1 stained both types of histiocytes while Oct-2 stained only the RDD component. CONCLUSIONS: PU.1 emerged as a robust marker with crisp nuclear staining in RDD histiocytes as well as in engulfed inflammatory cells. Strong coexpression of PU.1 and Oct-2 is a useful diagnostic marker in differentiating histiocytic/dendritic cell proliferations.

EBV-positive nodular lymphocyte predominant Hodgkin lymphoma: a single institution experience.

The objective of this study is to characterize the clinicopathologic features of Epstein-Barr virus (EBV)-positive nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) at a single institution. A retrospective review of cases diagnosed with EBV-positive NLPHL was performed and the patients' demographic and pathologic features were collected by chart review. In this study, we identified 17 EBV-positive NLPHL patients whose clinicopathologic features are characterized. EBV was positive in lymphocyte predominant (LP) cells in 6 of 17 cases, whereas the remaining cases showed EBV positivity in background small cells. Immunohistochemical analysis showed that LP cells were positive for CD20 (94.1%) in most cases and positive for OCT2 (100%) in all cases with one case showing weak OCT2 expression, whereas PAX5 and CD79a were weak and/or variable in 9 of 12 and 3 of 7 cases, respectively. CD30 was positive in 7 of 17 cases with 5 cases showing only scattered positive cells. In addition, we report a patient who had a history of EBV-negative NLPHL and showed EBV-positive NLPHL at the time of recurrence. Molecular studies performed on the 2 biopsies in the patient indicated EBV infection involving the NF-kB pathway. Our study shows that EBV-positive NLPHL is rare and may be diagnostically challenging because of atypical immunophenotypic features, such as partial expression of CD30, and weak/variable PAX5 and/or CD79a expression. The overall retention of the B-cell phenotype with strong and diffuse expression of CD20 and OCT2 in LP cells supports the diagnosis of EBV-positive NLPHL.

Intracholecystic papillary-tubular neoplasms of the gallbladder - A clinicopathological study of 36 cases.

Intracholecystic papillary-tubular neoplasms (ICPNs) account for <0.5% of all cholecystectomies. There is a lack of significant published data from the Indian subcontinent on ICPN to the best of our knowledge. The objective of the current study was to describe the clinicopathological features of ICPN of gallbladder from the departmental archives during a 5.5-year period. We also aimed to classify them into various histological subtypes and to correlate the clinicopathological parameters of ICPN with invasive adenocarcinoma. This study included 36 cases diagnosed over a period of 5.5 years (2013-2018). Clinical, radiological and histopathological data were analyzed in detail. The incidence of ICPN was 0.8%. The mean age of patients was 45.7 years with a female to male ratio of 1.3:1. Biliary phenotype was associated with invasion (p ≤0.001). Papillary pattern was present in 15 cases (41.6%) and was associated with invasion (p ≤0.001). High grade dysplasia was seen in 34 cases (94.4%), of which invasion was seen in 18 cases (50%). One case in our study also had synchronous common bile duct carcinoma. Majority (92%) of the patients were alive and well at the end of available follow-up (mean of 7 months and 25 days). ICPNs are mass forming neoplasms of the gallbladder with a slight female predominance. Biliary phenotype has an aggressive course, often associated with an invasive adenocarcinoma component. Papillary configuration of the lesion is significantly associated with an invasive component. Diligent follow-up of these lesions is warranted as they can be associated with other malignancies of the biliary system.

Histological and immunohistochemical study of hepatoblastoma: correlation with tumour behaviour and survival.

BACKGROUND: Hepatoblastoma (HB) has different histological subtypes, with varying prognosis. Though the survival has drastically improved, subsets of patients are not responsive to therapy. Therefore, it becomes important to determine the factors which affect the behaviour of the tumour. This study was aimed to look at the histopathological subtypes and compare with immunohistochemical (IHC) expression of CK19, beta-catenin and EpCAM and survival. METHODS: This study included 55 cases of HB. IHC expression of CK19, beta-catenin and EpCAM were correlated with histological subtypes, tumour behaviour, response to chemotherapy and survival. RESULTS: Most common epithelial subtype was fetal (43.2%) and mixed epithelial (54.8%) in pre- and post-chemotherapy groups respectively. Microvascular invasion (MVI) was present in 14/33 resected tumours. CK19 expression was seen in 54.2% and 72.2% of embryonal subtype, nuclear beta-catenin expression in 48.7% and 57.1% and EpCAM in 100% and 82.1% of tumours in pre- and post-chemotherapy groups, respectively. Fetal subtype had a lesser chance of MVI, recurrence, metastasis and death. Beta-catenin expression was associated with lower event free survival (EFS) and EpCAM with ≥50% viable tumour following chemotherapy (P=0.04). Age at diagnosis ≤2 years, male sex, alpha-fetoprotein <10,000 IU/mL following chemotherapy, solitary tumour (P=0.001), size ≤5 cm, pretreatment extent of disease (PRETEXT) I&II, mitosis ≤2/10 high power fields (hpf), viable tumour <50% (P=0.04) and absent nuclear expression of beta-catenin, predicted a higher EFS rate. CONCLUSIONS: Beta-catenin expression is associated with lower EFS and EpCAM expression with tumour viability. Multifocality and viable tumour ≥50% were significant factors predicting lower EFS. These factors should be included in the prognostication of HBs.

Malignant mixed Mullerian tumour of uterus secondary to tamoxifen therapy for hormone responsive breast cancer.

Tamoxifen is used in the treatment of hormone responsive breast cancer because of its antiestrogenic effect. However, it also has an estrogenic effect on the uterus, thereby increasing the risk of endometrial hyperplasia, endometrial polyp and endometrial neoplasms such as endometrial adenocarcinoma and malignant mixed Mullerian tumour (MMMT). This case describes the possible pathogenesis and risk of developing MMMT due to long-term tamoxifen intake in hormone responsive breast cancer.