NIPBL::NACC1 Fusion Hepatic Carcinoma

Several reports describing a rare primary liver tumor with histologic features reminiscent of follicular thyroid neoplasms have been published under a variety of descriptive terms including thyroid-like, solid tubulocystic, and cholangioblastic cholangiocarcinoma. Although these tumors are considered to represent histologic variants, they lack classic features of cholangiocarcinoma and have unique characteristics, namely immunoreactivity for inhibin and NIPBL::NACC1 fusions. The purpose of this study is to present clinicopathologic and molecular data for a large series of these tumors to better understand their pathogenesis. We identified 11 hepatic tumors with these features. Immunohistochemical and NACC1 and NIPBL fluorescence in situ hybridization assays were performed on all cases. Four cases had available material for whole-genome sequencing (WGS) analysis. Most patients were adult women (mean age: 42 y) who presented with abdominal pain and large hepatic masses (mean size: 14 cm). Ten patients had no known liver disease. Of the patients with follow-up information, 3/9 (33%) pursued aggressive behavior. All tumors were composed of bland cuboidal cells with follicular and solid/trabecular growth patterns in various combinations, were immunoreactive for inhibin, showed albumin mRNA by in situ hybridization, and harbored the NIPBL::NACC1 fusion by fluorescence in situ hybridization. WGS corroborated the presence of the fusion in all 4 tested cases, high tumor mutational burden in 2 cases, and over 30 structural variants per case in 3 sequenced tumors. The cases lacked mutations typical of conventional intrahepatic cholangiocarcinoma. In this report, we describe the largest series of primary inhibin-positive hepatic neoplasms harboring a NIPBL::NACC1 fusion and the first WGS analysis of these tumors. We propose to name this neoplasm NIPBL:NACC1 fusion hepatic carcinoma.

Immunoglobulin G4-Associated Rosai-Dorfman Disease: Report of 3 Cases

Rosai-Dorfman disease is characterized by dilated lymph node sinuses filled with lymphocytes, plasma cells, and histiocytes. Many of these histiocytes classically exhibit emperipolesis of lymphocytes and plasma cells. Abundant immunoglobulin G4+ plasma cells occur in some cases, and a potential relationship with immunoglobulin G4-related disease has been suggested. Here, we report 3 cases of immunoglobulin G4-associated Rosai-Dorfman disease. Immunoglobulin G4-related disease was suspected based on immunoglobulin G4+ plasma cell infiltration, but the final diagnosis was immunoglobulin G4-associated Rosai-Dorfman disease. At present, the evidence does not support a link between immunoglobulin G4-associated Rosai-Dorfman disease and immunoglobulin G4-related disease, and one condition should not be considered part of the spectrum of the other. We believe it is of paramount importance to increase the awareness of immunoglobulin G4-associated Rosai-Dorfman disease for pathologists who interpret the biopsies and clinicians who integrate the diagnosis and treat such patients to not overdiagnose immunoglobulin G4-related disease.

Causes of erythrocytosis and its impact as a risk factor for thrombosis according to etiology: experience in a referral center in Mexico City

Background

Thrombotic events are well documented in primary erythrocytosis, but it is uncertain if secondary etiologies increase the risk of thrombosis. This study aimed to determine the causes of erythrocytosis and to identify its impact as a risk factor for thrombosis.

Methods

Data were obtained from patients with erythrocytosis between 2000 and 2017 at a referral hospital in Mexico City. Erythrocytosis was defined according to the 2016 WHO classification. Time to thrombosis, major bleeding, or death were compared among groups of patients defined by the etiology of erythrocytosis using a Cox regression model, adjusting for cardiovascular risk factors.

Results

In total, 330 patients with erythrocytosis were studied. The main etiologies of erythrocytosis were obstructive sleep apnea (OSA) in 29%, polycythemia vera (PV) in 18%, and chronic lung disease (CLD) in 9.4% of the patients. The incidence rate of thrombosis was significantly higher in patients with PV and CLD than that in patients with OSA (incidence rates of 4.51 and 6.24 vs. 1.46 cases per 100 person-years, P=0.009), as well as the mortality rate (mortality rates of 2.72 and 2.43 vs. 0.17 cases per 100 person-years, P =0.003).

Conclusion

The risk of thrombosis in CLD with erythrocytosis was comparable to that in patients with PV. Further larger-scale studies are needed to confirm these findings and evaluate the benefits of preventive management of COPD with erythrocytosis similar to PV.

Rhipicephalus sanguineus Complex in the Americas: Systematic, Genetic Diversity, and Geographic Insights

The Rhipicephalus sanguineus group encompasses at least 12 validated species of Palearctic and Afrotropical hard ticks, which are relevant in veterinary medicine and public health. The taxonomy of R. sanguineus s.s., has been particularly intensely debated, due to its wide geographic distribution, morphological variants, parasite-host associations, and its capacity and vectorial competence for the transmission of several pathogens. By sequencing mitochondrial markers, it was possible to identify the existence of multiple lineages, among which the Tropical and the Temperate lineages stand out, particularly in America. However, the northern limit between these lineages is not clear due to the lack of extensive sampling across Mexico. For this reason, the aim of the present study was to determine the genetic diversity and structure of the R. sanguineus group in Mexico and to compare it with the populations reported in the Americas, in order to propose the northern limit of the R. sanguineus Tropical lineage and the potential regions of sympatry with R. sanguineus s.s. The findings of this study now confirm the presence of R. sanguineus s.s. in Mexico, showing a subtle genetic structure and high genetic diversity throughout its distribution in the Americas. In contrast, the Tropical lineage seems to be genetically less diverse in its overall distribution in the Americas. The genetic diversity of these two independent lineages could have important epidemiological implications in the transmission of tick pathogens.

The Role of Postmastectomy Radiotherapy in Locally Advanced Breast Cancer After Pathological Complete Response to Neoadjuvant Chemotherapy

The Case A previously healthy woman, aged 32 years, presented to the oncology clinic with a 6-month history of left-breast tumor, mastalgia, and swollen axillary nodes. Physical examination was relevant for a 6-cm palpable mass in the upper outer quadrant of the left breast and an ipsilateral 2-cm, nonfixed axillary lymph node. Mammography showed a 1-cm mass in the upper outer quadrant, a 5.2-cm mass in the lower outer quadrant, and enlarged pathologic lymph nodes (BI-RADS category 5 disease). Breast ultrasound revealed 3 axillary lymph nodes with cortical thickening and loss of normal morphology (the largest with a 2.6-cm length in the long axis) (Figure 1A-B). The breast´s core biopsy revealed a grade 3 apocrine invasive carcinoma with lymphovascular invasion; immunohistochemistry testing showed HER2-negative, hormone receptor-negative disease (estrogen receptor, 0%; progesterone receptor, 0%; HER2-negative, Ki67, 50%) (Figure 2A-B). A fine-needle aspiration biopsy of the axillary lymph nodes showed invasive breast carcinoma as well. Bone scintigraphy and a chest/abdomen CT scan ruled out metastatic disease. Upon initial diagnosis, clinical stage was deemed as cT3N1M0 (American Joint Committee on Cancer 8th edition: anatomic stage IIIA, clinical prognostic stage IIIC). After a multidisciplinary tumor board discussion, the patient underwent neoadjuvant chemotherapy with weekly paclitaxel, followed by 4 cycles of dose-dense doxorubicin plus cyclophosphamide. After completing neoadjuvant treatment, clinical examination was relevant for a residual 1-cm palpable left breast mass and no palpable axillary nodes. Mammography and breast ultrasound showed a 77% partial response in the primary tumors, and axillary nodes with normal morphology and size (Figure 1C-D). Due to multicentric tumor disease, breast-conserving surgery would not confer satisfactory cosmetic results on her, and a modified radical mastectomy with intraoperative sentinel lymph node biopsy (and second-stage breast reconstruction) was planned. However, during surgery, the surgeons failed to identify the mapped lymph node, and level I-III axillary lymph node dissection was performed. The pathology report described complete pathological response: Miller and Payne criteria grade 5 response with the absence of malignant cells within the mastectomy specimen and in 24 lymph nodes (Figure 2C-E). Pathological staging after neoadjuvant treatment concluded ypT0N0M0 disease. Subsequent treatment for this patient was discussed in another tumor board.

Clinical features of patients with Rocky Mountain spotted fever, dengue and chikungunya infection

INTRODUCTION

Clinical distinction between arbovirus infections and those caused by rickettsia is crucial to initiate appropriate medical treatment.

OBJECTIVE

To compare the differences between Rocky Mountain spotted fever (RMSF) and other vector-borne diseases (dengue and chikungunya) with similar clinical presentation, and to identify data that could aid rapid diagnosis of these diseases.

METHODS

We evaluated sociodemographic, clinical and laboratory data of 399 patients from five hospitals and clinics of Sonora, Mexico, between 2004 and 2016, with laboratory-confirmed diagnosis of RMSF, dengue, or chikungunya.

RESULTS

The RMSF group had the highest lethality (49/63 deaths, 77.8 %), followed by the chikungunya group (3/161, 1.9 %) and the dengue group (3/161, 1.9 %). Clinical differences included the presence of rash, edema, and pruritus; in addition, differences in multiple biomarkers such as platelets, hemoglobin, indirect bilirubin, and serum sodium levels were documented.

CONCLUSION

Rash on the palms and soles, edema and absence of pruritus, together with high levels of direct bilirubin and severe thrombocytopenia could be useful indicators to differentiate patients at RMSF advanced stages from those with dengue and chikungunya.

The genus Rickettsia in Mexico: Current knowledge and perspectives

The genus Rickettsia encompasses 35 valid species of intracellular, coccobacilli bacteria that can infect several eukaryotic taxa, causing multiple emerging and re-emerging diseases worldwide. This work aimed to gather and summarise the current knowledge about the genus Rickettsia in Mexico, updating the taxonomy of the bacteria and their hosts by including all the records available until 2020, to elucidate host-parasite relationships and determine the geographical distribution of each Rickettsia species present in the country. Until now, 14 species of Rickettsia belonging to four groups have been recorded in Mexico. These species have been associated with 26 arthropod species (14 hard ticks, three soft ticks, two sucking lice, and seven fleas) and 17 mammal species distributed over 30 states in Mexico. This work highlights the high biological inventory of rickettsias for Mexico and reinforces the need to approach the study of this group from a One Health perspective.

Molecular Confirmation of Rickettsia parkeri in Amblyomma ovale Ticks, Veracruz, Mexico

We found Rickettsia parkeri in Amblyomma ovale ticks collected in Veracruz, Mexico, in 2018. We sequenced gene segments of gltA, htrA, sca0, and sca5; phylogenetic reconstruction revealed near-complete identity with R. parkeri strain Atlantic Rainforest. Enhanced surveillance is needed in Mexico to determine the public health relevance of this bacterium.

Rickettsia parkeri and Candidatus Rickettsia andeanae in Tick of the Amblyomma maculatum Group, Mexico

We report Rickettsia parkeri and Candidatus Rickettsia andeanae in ticks of the Amblyomma maculatum group collected from dogs in Sonora, Mexico. Molecular characterization of these bacteria was accomplished by DNA amplification and sequence analysis of portions of the rickettsial genes gltA, htrA, ompA, and ompB.

Molecular evidence of Borrelia burgdorferi sensu stricto and Rickettsia massiliae in ticks collected from a domestic-wild carnivore interface in Chihuahua, Mexico

Sixty-five wild carnivores and twenty free-roaming dogs from the Janos Biosphere Reserve (JBR), northwestern Chihuahua, Mexico, were inspected for ticks which were tested by molecular assays to identify Borrelia and Rickettsia infections. Overall, 45 ticks belonging to five taxa, including Dermacentor parumapertus, Ixodes hearlei, Ixodes kingi, Rhipicephalus sanguineus s.l., and Ornithodoros sp. were collected from 9.2% of the wild carnivores and 60% of the free-roaming dogs. Borrelia burgdorferi s.s. DNA was detected in an I. kingi tick collected from a kit fox (Vulpes macrotis), while Rickettsia massiliae was detected in two (6.5%) of the 31 Rh. sanguineus s.l. collected from free-roaming dogs. Our results revealed host associations between free-roaming dogs and wild carnivore hosts and their ticks in the JBR. The presence of the etiological agents of Lyme disease and spotted fever rickettsiosis in ticks raises the potential risk of tick-borne diseases at the human-domestic-wildlife interface in northwestern Mexico.

Rickettsia parkeri in Dermacentor parumapertus Ticks, Mexico

During a study to identify zoonotic pathogens in northwestern Mexico, we detected the presence of a rickettsial agent in Dermacentor parumapertus ticks from black-tailed jackrabbits (Lepus californicus). Comparison of 4 gene sequences (gltA, htrA, ompA, and ompB) of this agent showed 99%–100% identity with sequences of Rickettsia parkeri.

[Fatal case of co-infected of rickettiosis and dengue virus in Mexico]

BACKGROUND

Rocky Mountain spotted fever (RMSF) is a disease spread by an infected tick and it is lethal if patient is not treated on time. Symptom similarities with other exanthematous diseases may delay the diagnosis, which leads to its mortality.

CLINICAL CASE

We show the lethal case of a patient with medical record of high blood pressure and no history of travel, who lived in Sonora, Mexico. At the beginning, it was suspected that the patient had a dengue virus infection, which was confirmed positive by an ELISA test. Patient’s rapid deterioration, multi-organic failure and the characteristics of her exanthema led to the suspicion of the presence of RMSF. We started doxycycline treatment; however, patient died after seven days of evolution. It was confirmed a co-infection of Rickettssia spp. and dengue virus.

CONCLUSION

In rickettsial endemic zones, treatment with doxycycline should be employed in patients with similar symptoms, even though there is evidence of the presence of other etiologic agents.

[Rocky Mountain spotted fever in Mexican children: Clinical and mortality factors]

OBJECTIVE

Characterize clinical manifestations and predictors of mortality in children hospitalized for spotted fever.

MATERIALS AND METHODS

Cross-sectional study in 210 subjects with a diagnosis of Rocky Mountain spotted fever (RMSF) in a pediatric hospital in Sonora, from January 1st, 2004 to June 30th, 2015. Data were analyzed using descriptive statistics and multivariate logistic regression.

RESULTS

An upward trend was observed in RMSF morbidity and mortality. Fatality rate was 30%.Three predictors were associated with risk of death: delay ≥ 5 days at the start of doxycycline (ORa= 2.95, 95% CI 1.10-7.95), acute renal failure ((ORa= 8.79, 95% CI 3.46-22.33) and severe sepsis (ORa= 3.71, 95% CI 1.44-9.58).

CONCLUSIONS

RMSF causes high mortality in children, which can be avoided with timely initiation of doxycycline. Acute renal failure and severe sepsis are two independent predictors of death in children with RMSF.