Primary Rosai-Dorfman disease of the central nervous system: A clinical, histological, and molecular appraisal.

Rosai-Dorfman disease (RDD) is characterized by clonal proliferation of S-100 positive histiocytes and variable emperipolesis. It commonly affects cervical lymph nodes. Central nervous system (CNS) involvement is extremely rare. We attempted to evaluate the Cyclin D1 expression and frequency of KRAS and BRAF mutations in the RDD involving the CNS. All patients with histopathologically diagnosed RDD involving CNS were recruited from 2011 to 2022. All cases were subjected to immunohistochemistry for CD68, CD163, S100, CD1a, GFAP, CD207, EMA, ALK, BRAFV600E, IgG4, IgG, and CyclinD1. The real-time polymerase chain reaction (RT-PCR) for hotspot mutation analysis of KRAS (exons 2, 3, and 4) and BRAF (V600E) was conducted on formalin-fixed paraffin-embedded tissue using a commercial kit (EntroGen). A total of seven cases were included. The median age was 31 years, with six men and one woman. It showed spinal cord (n = 4) and intracranial (n = 3) involvement. Histologically, all cases showed histiocyte-rich inflammation with evidence of emperipolesis. These histiocytes were positive for S100, CD68, CD163, and Cyclin D1, whereas negative for CD1a, CD207, and EMA. BRAF V600E was expressed in a single case. None of the control cases (demyelination and infarction) with histiocytic infiltrate showed Cyclin D1 expression. Four RDD cases showed increased IgG4-positive plasma cells (>10/HPF) and IgG4/IgG ratio (>40%). BRAF V600E mutation was detected in one case (14.28%), while none showed KRAS mutation. RDD involving CNS is extremely rare and diagnostically challenging. Nuclear Cyclin D1 expression along with S-100 positivity in the tumor cells is a strong diagnostic clue. BRAF and KRAS mutations are rare in CNS RDD.

Hepatic alveolar echinococcosis simulating metastatic malignancy.

Echinococcosis is a parasitic disease caused by infection with tiny tapeworms of the genus Echinococcus. Echinococcosis is classified as either cystic echinococcosis or alveolar echinococcosis. The common form is a zoonosis from goats and sheep that tends to cause liver lesions. The larval stage of Echinococcus multilocularis causes alveolar echinococcosis/alveolar hydatid disease. It is a zoonosis with field mice and tundra voles as intermediate and wild carnivores like foxes and wolves as definitive hosts. This zoonosis is highly uncommon compared to the other form known as cystic echinococcosis but poses a great human threat if untreated. We report the case of a young man who was working in the Kashmir Valley, North India, and presented with jaundice and right upper quadrant abdominal pain. Computed tomography revealed a large solid-cystic intrahepatic lesion measuring 125x118x123 mm, suggestive of a malignant tumor with central necrosis. A liver biopsy showed necrosis with PAS-positive membranes morphologically consistent with echinococcosis. Alveolar echinococcosis can present as a solid-cystic mass in the liver and can simulate metastatic malignancy.

Adult Pulmonary Blastoma: A Case Report with Spectrum of Rare Manifestations.

Pulmonary blastoma (PB) is an exceedingly rare and aggressive malignant lung neoplasm that has distinct biphasic morphology. In this report, we document rare manifestations and molecular alterations in PB. A 59-year-old non-smoker female, presented with cough and hemoptysis for 4 months. The high-resolution computed tomography chest scan showed a 3.5x2.7 cm mass in the basal segment of the left lung. Positron emission tomography and computed tomography revealed a fluorodeoxyglucose avid lobulated mass in the superior segment of the lower lobe of the left lung. On core biopsy, the diagnosis of pleomorphic carcinoma in a background of adenocarcinoma was made. A definite diagnosis of pulmonary blastoma was established on the left lung lobectomy specimen based on morphological and immunohistochemical findings. Post-surgical biopsy from the scalp swelling showed metastatic deposits. On Next Generation Sequencing (NGS), in addition to conventional CTNNB1 gene mutation, new pathogenic MYCN and ATM gene mutations were detected. Post-chemotherapy, the patient was doing well after 10 months of close follow-up. PB exhibited rare associations in the form of non-smoker status, scalp metastasis, and MYCN and ATM gene mutations on NGS in addition to conventional CTNNB1 gene mutation. Large cohort studies are required to discover the incidence, significance and therapeutic implications of these co-existing pathogenic molecular alterations in PB.

Hepatic alveolar echinococcosis simulating metastatic malignancy

ABSTRACT Echinococcosis is a parasitic disease caused by infection with tiny tapeworms of the genus Echinococcus. Echinococcosis is classified as either cystic echinococcosis or alveolar echinococcosis. The common form is a zoonosis from goats and sheep that tends to cause liver lesions. The larval stage of Echinococcus multilocularis causes alveolar echinococcosis/alveolar hydatid disease. It is a zoonosis with field mice and tundra voles as intermediate and wild carnivores like foxes and wolves as definitive hosts. This zoonosis is highly uncommon compared to the other form known as cystic echinococcosis but poses a great human threat if untreated. We report the case of a young man who was working in the Kashmir Valley, North India, and presented with jaundice and right upper quadrant abdominal pain. Computed tomography revealed a large solid-cystic intrahepatic lesion measuring 125x118x123 mm, suggestive of a malignant tumor with central necrosis. A liver biopsy showed necrosis with PAS-positive membranes morphologically consistent with echinococcosis. Alveolar echinococcosis can present as a solid-cystic mass in the liver and can simulate metastatic malignancy.

Alcoholic foamy degeneration: an unusual presentation of the alcoholic liver disease diagnosed on autopsy.

Alcoholic foamy degeneration (AFD) is an uncommon presentation of alcoholic liver disease (ALD) with characteristic histologic findings of foamy-looking hepatocytes due to the presence of abundant microvesicles of fat within the cytoplasm predominantly in perivenular and midzonal regions without inflammation and fibrosis. It is underdiagnosed as the patients quickly recover after alcoholic abstinence and are rarely caught on biopsies. AFD has better prognosis than alcoholic hepatitis, and the injury mechanism is different, warranting a different diagnosis. We present an uncommon case of AFD incidentally diagnosed during autopsy in a chronic alcoholic and diabetic man.

Biliary adenofibroma: a precursor lesion of intrahepatic cholangiocarcinoma.

Biliary adenofibroma (BAF) is an uncommon liver tumor with a high propensity for malignant transformation. The histomorphology of BAF with malignant transformation can show a spectrum of changes ranging from benign, dysplastic to frank malignancy. Thus, the diagnosis of BAF imposes the pursuit of dysplasia/ malignancy focus. We presented a case of intrahepatic cholangiocarcinoma arising from BAF in a 49-year-old woman with detailed histomorphology. We also performed a PubMed database search and tabulated all previously reported cases of BAF with dysplasia/ malignant transformation. A statistic comparison of age, sex ratio, size of the tumor, and survival following complete resection between BAFs with and without dysplasia/ malignancy from the retrieved data is presented. Our analysis did not highlight any statistically significant difference between BAFs with and without dysplasia/ malignancy in age, sex ratio, tumor size, and survival following complete surgical resection. Our study highlights the histopathology and immunohistochemistry of a case of BAF with malignant transformation and highlights the importance of this diagnosis in management. Further longitudinal studies on a larger cohort of patients are required to validate our findings.

Hemophagocytic Lymphohistiocytosis due to Disseminated Histoplasmosis in a Patient with HIV Infection.

Hemophagocytic lymphohistiocytosis is usually considered a rapidly progressive fatal illness with poor outcomes. It is of two types: primary or familial and secondary. In patients with HIV, opportunistic infections are the secondary triggers of HLH. First line of management of infection associated HLH is treatment of the underlying infection. Here, we present a case of HLH in HIV infection due to disseminated histoplasmosis managed with liposomal amphotericin B, who required immunosuppressive therapy with intravenous immunoglobulin and dexamethasone due to nonresponse to primary therapy.

Clinical, histopathological, and immunohistochemical spectrum of hepatolithiasis: a tertiary care center-based study from north India.

Hepatolithiasis (HL), an uncommon disease among Indians, occurs due to a complex interplay of various structural and functional factors. We retrospectively evaluated the clinical and histopathological spectrum of HL (N = 19) with immunohistochemical evaluation for biliary apomucins and canalicular transporter proteins, both crucial for lithogenesis. Nineteen surgically resected cases were included. Histopathology was systematically evaluated. Immunohistochemistry for apomucins (MUC1, MUC2, MUC4, MUC5AC, and MUC6) and canalicular transporter proteins (BSEP and MDR3) was applied to all cases. The median age was 51 years with female preponderance (F:M = 1.4:1). The stone was cholesterol-rich in 71.4% and pigmented in 28.6% (n = 14). Histopathology showed variable large bile-duct thickening due to fibrosis and inflammation with peribiliary gland hyperplasia. Structural causes (Caroli disease, choledochal cyst, and post-surgical complication) were noted in 15.8% of cases (secondary HL). Expression of gel-forming apomucin MUC1, MUC2, and MUC5AC was seen in either bile duct epithelia or peribiliary glands in 84.2%, 10.5%, and 84.2% cases respectively. Loss of canalicular expression of MDR3 was noted in 42.1% of cases while BSEP was retained in all. Primary HL in the north Indian population can be associated with the loss of MDR3 expression (with retained BSEP) and/ or a shift in the phenotype of biliary apomucins to gel-forming apomucins. The former factor alters the bile acid/ phospholipid ratio while the latter parameter promulgates crystallization. In conjunction, these factors are responsible for the dominantly cholesterol-rich stones in the index population.

Association between intraoperative anatomical variation and histopathological parameters in cases of ureteropelvic junction obstruction in children: A cross-sectional study.

Introduction: The intraoperative anatomical findings (IOAF) of all ureteropelvic junction obstruction (UPJO) cases are not identical. Moreover, there is also controversy in the literature regarding histopathological (HP) findings in cases of UPJO. In the present study, we evaluated different IOAF and assessed their association with specific HP parameters. Materials and Methods: This was a cross-sectional study set-up, which was carried out in a tertiary care centre. Children with UPJO who underwent surgery between 2017 and 2020 were enrolled. The following IOAF were noted: Type of pelvis (extrarenal or intrarenal), insertion of the ureter (high or normal), presence of lower pole crossing vessel (CV), negotiation of UPJ segment with double J stent (3 Fr) and length of internal narrowing (LIN) at UPJ. The resected segment of UPJ was assessed at three levels (pelvis, UPJ and ureter) for various HP parameters including fibrosis, oedema, inflammation and smooth muscle hypertrophy (SMH). Results: Thirty-nine children were included in the study with a mean age of 31 months. The summary statistics of IOAF were intrarenal pelvis in 5 cases, high insertion of the ureter (HIU) in 9, CV in 6, negotiable UPJ in 23, and 16 cases showed LIN >1 cm. All cases showed SMH at the pelvis region and SMH with fibrosis at the UPJ region. At the pelvis region, there was an association between (1) HIU with oedema and chronic inflammation (CIF), (2) CV with CIF and (3) LIN with CIF and SMH. At the UPJ region, there was an association between (1) CV and negotiable UPJ with less fibrosis and (2) LIN with SMH. At the ureteric end, CV showed an association with less fibrosis and more CIF. Conclusion: All UPJO cases have some common HP findings. Although, some particular IOAF, i.e., presence of CV, negotiable UPJ, HIU and LIN showed association with specific HP parameters.

Double-hit and double-expressor primary central nervous system lymphoma: Experience from North India of an infrequent but aggressive variant.

Background: High-grade non-Hodgkin B-cell lymphoma is an aggressive mature B-cell lymphoma that depicts poor treatment response and worse prognosis. The presence of MYC and B-cell lymphoma 2 (BCL2) and/or B-cell lymphoma 6 (BCL6) rearrangements qualifies for triple-hit and double-hit lymphomas (THL/DHL), respectively. We attempted to explore the incidence, distribution, and clinical characteristics of the primary high-grade B-cell lymphoma of the central nervous system (CNS) in our cohort from North India. Methods: All the histologically confirmed cases of primary CNS diffuse large B-cell lymphoma (PCNS-DLBCL) over a period of 8 years were included. Cases showing MYC and BCL2 and/or BCL6 expression on immunohistochemistry (IHC) (double- or triple-expressor) were further analyzed by fluorescence in situ hybridization for MYC, BCL2 and /or BCL6 rearrangements. The results were correlated with other clinical and pathological parameters, and outcome. Results: Of total 117 cases of PCNS-DLBCL, there were seven (5.9%) cases of double/triple-expressor lymphomas (DEL/TEL) (six double- and one triple-expressor) with median age of 51 years (age range: 31-77 years) and slight female predilection. All were located supratentorially and were of non-geminal center B-cell phenotype. Only triple-expressor case (MYC+/BCL2+/BCL6+) demonstrated concurrent rearrangements for MYC and BCL6 genes indicating DHL (n = 1, 0.85%), while none of the double-expressors (n = 6) showed MYC, BCL2, or BCL6 rearrangements. The mean overall survival of the DEL/TEL was 48.2 days. Conclusion: DEL/TEL and DHL are uncommon in CNS; mostly located supratentorially and are associated with poor outcome. MYC, BCL2, and BCL6 IHC can be used as an effective screening strategy for ruling out double/ triple-expressor PCNS-DLBCLs.

Autopsy findings of acute erythroid leukemia.

Acute erythroid leukemia (AEL) is an exceedingly uncommon but distinct hematological malignancy that shows neoplastic proliferation of erythroid precursors with maturation arrest and no significant myeloblasts. We describe an autopsy case of this rare entity in a 62-year-old man with co-morbidities. He underwent a bone marrow (BM) examination for pancytopenia during the first outpatient department visit, which revealed an increased number of erythroid precursors with dysmegakaryopoiesis suggesting the possibility of Myelodysplastic syndromes (MDS). Thereafter, his cytopenia got worsened, warranting blood and platelet transfusions. Four weeks later on the second BM examination, AEL was diagnosed based on morphology and immunophenotyping. Targeted resequencing for myeloid mutations revealed TP53 and DNMT3A mutations. He was initially managed along febrile neutropenia with the stepwise escalation of antibiotics. He developed hypoxia attributed to anemic heart failure. Subsequently, he had hypotension and respiratory fatigue pre-terminally and succumbed to his Illness. A complete autopsy showed infiltration of various organs by AEL and leukostasis. Besides, there was extramedullary hematopoiesis, arterionephrosclerosis, diabetic nephropathy (ISN-RPS class II), mixed dust pneumoconiosis, and pulmonary arteriopathy. The histomorphology of AEL was challenging, and the differential diagnoses were many. Thus, this case highlights the autopsy pathology of AEL, an uncommon entity with a strict definition, and its relevant differentials.

Endobronchial Sialolipoma: An Uncommon Salivary Gland Tumor at an Uncommon Site.

BACKGROUND: Sialolipoma is a benign neoplasm composed of neoplastic adipose tissue and normal salivary gland parenchyma. It is commonly seen in the parotid gland. The occurrence of sialolipoma in the main bronchus is exceedingly rare. CASE REPORT: A 52-year-old diabetic and hypertensive gentleman presented with shortness of breath and cough for the last 3-4 months. Computed tomography bronchial angiography showed a soft tissue lesion in the right intermediate bronchus causing its complete obliteration and subsequent collapse of the right lower lobe. A rigid tracheobronchoscope revealed a polypoidal growth originating in the right intermediate bronchus. Histopathology revealed a sialolipoma. The patient was doing well on follow-up and no recurrence was noted to date. CONCLUSION: The bronchus as the primary site for sialolipoma is unusual and has to be kept in the differential while dealing with the slow-growing endobronchial tumor.

An Enigmatic Case of Jaundice and Photosensitivity in an Adolescent.

Erythropoietic protoporphyria (EPP) presents with nonblistering photosensitivity. Hepatobiliary manifestations are seen in around 5% cases and include cholelithiasis, elevations in liver enzymes, progressive jaundice, and end-stage liver disease. The diagnosis is suspected based on clinical features and elevated erythrocyte metal-free protoporphyrin and confirmed by genetic analysis showing loss-of-function mutations in the ferrochelatase (FECH) gene. We present an adolescent boy who presented with jaundice and photosensitivity with the liver biopsy showing deposition of brown pigments within the canaliculi and hepatocytes. This pigment showed Maltese cross birefringence on polarizing microscopy and Medusa-head appearance on electron microscopy. Genetic analysis revealed loss-of-function mutations in FECH. Introduction of EPP is an inborn error of heme biosynthesis caused by mutations in FECH with a prevalence of 1:75,000 to 1:200,000. We present a case of a 16-year-old adolescent boy with photosensitivity, abdominal pain, and jaundice with protoporphyrin deposition in the liver who was ultimately diagnosed with EPP based on genetic analysis.