Crossing the Andes: Challenges and opportunities for digital pathology in Latin America

The most widely accepted and used type of digital pathology (DP) is whole-slide imaging (WSI). The USFDA granted two WSI system approvals for primary diagnosis, the first in 2017. In Latin America, DP has the potential to reshape healthcare by enhancing diagnostic capabilities through artificial intelligence (AI) and standardizing pathology reports. Yet, we must tackle regulatory hurdles, training, resource availability, and unique challenges to the region. Collectively addressing these hurdles can enable the region to harness DP's advantages-enhancing disease diagnosis, medical research, and healthcare accessibility for its population. Americas Health Foundation assembled a panel of Latin American pathologists who are experts in DP to assess the hurdles to implementing it into pathologists' workflows in the region and provide recommendations for overcoming them. Some key steps recommended include creating a Latin American Society of Digital Pathology to provide continuing education, developing AI models trained on the Latin American population, establishing national regulatory frameworks for protecting the data, and standardizing formats for DP images to ensure that pathologists can collaborate and validate specimens across the various DP platforms.

Brain tuberculoma in pediatric heart transplant recipient

INTRODUCTION

Heart transplantation is the standard treatment for end-stage heart disease. Despite advances in the field, patients remain under risk of developing complications, including opportunistic infections, such as tuberculosis. We present the unprecedented case of cerebral tuberculoma in a 9-year-old heart transplant recipient.

CASE SCENARIO

A 9-year-old female child, who underwent heart transplantation in December 2020, was admitted to the emergency department in September 2021 due to headache and vomiting. She had normal vital signs and a mild left hemiparesis. Laboratory findings included lymphopenia and a low C Reactive Protein and brain images showed expansive lesions. A biopsy of the intracranial lesion was performed and anatomopathological analysis was compatible with tuberculoma. After the diagnosis was established, treatment protocol for neurotuberculosis was initiated, the patient had a satisfactory clinical evolution and was discharged 22 days after admission.

DISCUSSION

Clinical manifestation of tuberculosis usually occurs up to 6 months after transplantation, the findings are commonly atypical and symptoms may be mild. We could not find in medical literature any description of the disease in a heart transplant recipient as young as the one presented in this case report. We documented great response to treatment, even though conventional antituberculosis therapy may interfere with immunosuppression.

CONCLUSION

Patients in the postoperative period following heart transplantation are at high risk for developing opportunistic infections such as tuberculosis, which may present with atypical symptoms. Therefore the clinician must have a high index of suspicion in order to make the correct diagnosis and promptly start treatment.

Survivin: A Potential Marker of Resistance to Somatostatin Receptor Ligands

CONTEXT

Invasive and somatostatin receptor ligand (SRL)-resistant pituitary tumors represent a challenge in the clinical practice of endocrinologists. Efforts have been made to elucidate reliable makers for both. Survivin and eukaryotic translation initiation factor-binding protein 1 (4EBP1) are upregulated in several cancers and involved in apoptosis and cell proliferation.

OBJECTIVE

We explored the role of these markers in somatotropinomas.

METHODS

Immunostains for survivin and 4EBP1, and also for somatostatin receptor type 2 (SSTR2), Ki-67, and cytokeratin 18, were analyzed in tissue microarrays containing 52 somatotropinoma samples. Tumor invasiveness was evaluated in all samples while drug resistance was evaluated in 34 patients who received SRL treatment. All these parameters were correlated with first-generation SRL (fg-SRL) responsiveness and tumor invasiveness.

RESULTS

Low survivin expression (P = 0.04), hyperintense signal on T2 weighted image (T2WI) (P = 0.01), younger age (P = 0.01), sparsely granular adenomas (SGA) (P = 0.04), high postoperative growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels (P = 0.049 and P < 0.001, respectively), and large postoperative tumor size (P = 0.02) were associated with resistance to fg-SRL. Low survivin and SSTR2 expression and high 4EBP1 expression were associated with SGA (P = 0.04, P = 0.01, and P = 0.001, respectively). Younger age (P = 0.03), large tumor pre- and postoperative (P = 0.04 and P = 0.006, respectively), low SSTR2 expression (P = 0.03), and high baseline GH and IGF-1 (P = 0.01 and P = 0.02, respectively) were associated with tumor invasiveness. However, survivin, 4EBP1, Ki-67, and granulation patterns were not associated with tumor invasion.

CONCLUSION

This study suggests that low survivin expression is predictive of resistance to fg-SRL in somatotropinomas, but not of tumor invasiveness.

Neuropathology of yellow fever autopsy cases

BACKGROUND

Yellow fever is a viral hemorrhagic fever caused by yellow fever virus, a mosquito-borne flavivirus. Despite an effective vaccine, major outbreaks continue to occur around the world. Even though it is not a proven neurotropic virus, neurological symptoms in more severe clinical forms are frequent. The understanding of this apparent paradox is still rarely addressed in literature.

METHODS

The brains of thirty-eight patients with yellow fever confirmed by RT-PCR, who underwent autopsy, were analyzed morphologically to identify and characterize neuropathological changes. The data were compared with brains collected from individuals without the disease, as a control group. Both cases and controls were subdivided according to the presence or absence of co-concurrent septic shock, to exclude changes of the sepsis associated encephalopathy. To verify possible morphological differences between the yellow fever cases groups, between the control groups, and between the cases and the controls, we applied the statistical tests Fisher's exact test and chi-square, with p values < 0.05 considered statistically significant.

RESULTS

All cases and controls presented, at least focally, neuropathological changes, which included edema, meningeal and parenchymal inflammatory infiltrate and hemorrhages, and perivascular inflammatory infiltrate. We did not find an unequivocal aspect of encephalitis. The only parameter that, after statistical analysis, can be attributed to yellow fever was the perivascular inflammatory infiltrate.

CONCLUSIONS

The neuropathological findings are sufficient to justify the multiple clinical neurologic disturbances detected in the YF cases. Since most of the parameters evaluated did not show statistically significant difference between cases and controls, an explanation for most of the neuropathological findings may be the vascular changes, consequent to shock induced endotheliopathy, associated with stimulation of the immune system inherent to systemic infectious processes. The statistical difference obtained in yellow fever cases regarding perivascular infiltrate can be can be explained by the immune activation inherent to the condition.

ATRT-06. Atypical Teratoid Rhabdoid Tumors (ATRT): results from a Single Institution in Brazil - São Paulo University

OBJECTIVES: Atypical teratoid/rhabdoid tumor (AT/RT) is a rare, highly malignant tumor of the central nervous system with poor prognosis. Nowadays, multimodal management, including surgery, chemotherapy (CMT), radiation therapy (RT) and Bone Marrow Transplantation (BMT). The aim of this study was to assess the experience and survival in a center of reference of treatment in childhood cancer in Brazil. PATIENTS AND METHODS: Medical records of AT/RT patients who underwent surgery from 2008 to 2020 at a center of childhood cancer treatment (ITACI) in São Paulo University were retrospectively reviewed and statistically analyzed. RESULTS: Eight patients (2 males and 6 females) were presented with AT/RTs. Median age during presentation was 22 months (range, 0 - 6 years). Seven patients (88%) were < 18 months and one patient were >18 months. Tumor location was supratentorial in four patients, infratentorial in 2 patients. Kidney disease as the primary diagnosis in 2 patients (25%). Surgical treatment was performed in 4 patients. Seven children underwent total CMT and 3 children were treated with RT. Only 3 patients underwent Autologous Bone Marrow Transplantation (ABMT). The chemotherapy management protocol of the patients was variable: 2 patients received the EU-RHAB protocol, 2 patients received the HEAD START III protocol, 3 patients received chemotherapy in the ICE regimen (Ifosfamide + Carboplatin + Etoposide) and 1 patient received chemotherapy in the CDDP+CTX+VCR (Cyclophosphamide + Cisplatin + Vincristine) regimen. All patients had episodes of neutropenic fever when they received chemotherapy, requiring hospitalization and use of an antibiotic treatment. Among the 8 patients analyzed, all died. CONCLUSIONS: Despite progress in treatment, AT/RT of the CNS disease or primary kidney disease associated with a lack of standardization in a regimen contributes to the dismal prognosis. There is a high mortality in patients with AT/RT, similar to that found in the literature.

Loss of an eye to mucormycosis following corticosteroid therapy for COVID-19

Mucormycosis is a rare, sometimes severe fungal infection that has emerged as a possible complication of COVID-19. We report a case of a non-diabetic, apparently immunocompetent patient diagnosed with rhino-orbital-cerebral mucormycosis shortly after COVID-19 treatment with dexamethasone. The patient received optimized systemic antifungal therapy and extensive surgical treatment. So far, four months after the last hospital discharge, the patient has been in good general condition. This case is a dramatic reminder that beneficial corticosteroid therapy in general inevitably carries a risk of opportunistic infection, and corticosteroid therapy for COVID-19 risks orbital-rhinocerebral mucormycosis that clinicians should watch for with vigilance.

Systemic dengue infection associated with a new dengue virus type 2 introduction in Brazil - a case report

BACKGROUND

Dengue infection is caused by an arbovirus with a wide range of presentations, varying from asymptomatic disease to unspecific febrile illness and haemorrhagic syndrome with shock, which can evolve to death. In Brazil, the virus circulates since the 1980s with many introductions of new serotypes, genotypes, and lineages since then. Here we report a fatal case of dengue associated with a Dengue virus (DENV) lineage not detected in the country until now.

CASE PRESENTATION

The patient, a 58-year-old man arrived at the hospital complaining of fever and severe abdominal pain due to intense gallbladder edema, mimicking acute abdomen. After 48 h of hospital admission, he evolved to refractory shock and death. DENV RNA was detected in all tissues collected (heart, lung, brain, kidney, spleen, pancreas, liver, and testis). Viral sequencing has shown that the virus belongs to serotype 2, American/Asian genotype, in a new clade, which has never been identified in Brazil before. The virus was phylogenetically related to isolates from central America [Puerto Rico (2005-2007), Martinique (2005), and Guadeloupe (2006)], most likely arriving in Brazil from Puerto Rico.

CONCLUSION

In summary, this was the first fatal documented case with systemic dengue infection associated with the new introduction of Dengue type 2 virus in Brazil during the 2019 outbreak.

Extranodal NK/T-cell lymphoma, nasal type with extensive cardiopulmonary involvement

Extranodal NK/T-cell lymphoma, nasal type (ENKTL-NT) is a rare type of Non-Hodgkin’s lymphoma, which usually presents with extranodal involvement and affects the nasal/upper aerodigestive tract in the classical presentation. Herein, we report the case of a 31-year-old, previously healthy, male patient diagnosed with ENKTL-NT with the involvement of the lung parenchyma and heart. Unfortunately, due to the rapid disease progression, the diagnosis was performed only at the autopsy. The authors highlight the rare clinical presentation of this type of lymphoma, as well as the challenging anatomopathological diagnosis in necrotic samples.

Myasthenia Gravis Related to Thymic Carcinoma: A Case Study

Myasthenia gravis and thymoma are often presented in association with ∼10% of myasthenic cases having concomitant thymoma. Thymic carcinoma is one of the rarest/aggressive human epithelial tumors and has no correlation with myasthenia gravis hitherto. Here is provided a clinical case and review of literature on a very rare association of thymic carcinoma (with no sign of thymoma) and myasthenia gravis (antiacetylcholine receptor antibody positive). Two years after thymectomy, clinical evolution was satisfactory. This clinical case elicits hypothesis that thymic carcinoma may be related with myasthenia gravis, what may have good prognostic from oncologic and neurologic perspectives.

Orbit ossifying fibroma - Case report and literature review

Background:

Ossifying fibroma (OF) is benign bone lesions, most frequent in young children, more common in the maxillary sinus and mandible (75–89%), the pathogenesis of the tumor is not clear, there are many subtypes of OF. This paper aims to report an OF a case and literature review.

Case Description:

Male, 19 years old, with a progressive history proptosis since 2012, diagnosed as a right supraorbital lesion at an external service and assigned to conservative management. Then, he evolved with double vision, which worsened in February of 2018, associated with a moderate headache. On admission: proptosis and downward deviation of the right orbit was noticed on the physical exam and with exception of limited right upgaze, external ocular movements were maintained. Head computed tomography showed a multiloculate expansive osteolytic lesion at the right orbital roof. On magnetic resonance imaging, the lesion had an inner content with septations, T1-weighted imaging heterogeneous signal, T2-weighted imaging high signal intensity, and peripheral contrast enhancement. The patient underwent a right frontal craniotomy with a gross total resection and the postoperative follow-up was uneventful. Menzel reported the first case in 1782. The clinical findings depend on localization. There are five subtypes. In general, the lesions have a radiological appearance with hyperdense boundary and cause deformity and destruction in bones with high recurrence risk. Radical resection is curative.

Conclusion:

As a result, the correlation of clinical, radiologic, and pathologic data is significant while going for a specific diagnosis in cases of craniofacial fibrous lesions. Total excision is the best treatment, but it can recur.

Cushing's disease due to somatic USP8 mutations: a systematic review and meta-analysis

PURPOSE

Cushing's disease (CD) is a severe illness generally caused by microcorticotropinomas (MICs) and in approximately 7-20% of patients by macrocorticotropinomas (MACs). USP8-mutations have been identified as a major genetic cause of CD (~ 50%). Few studies have reported the distribution between MICs-MACs related to USP8-mutations and their genotype-phenotype correlations. Therefore, we aimed to evaluate USP8-mutations in a cohort of MICs-MACs from a unique center and to perform a systematic review and meta-analysis.

METHODS

DNA-tumor-tissues from 47 corticotropinomas (16 MICs and 31 MACs) were sequenced. Clinical-biochemical data, radiological imaging data and remission/recurrence rates were evaluated. In addition, we performed a meta-analysis of nine published series (n = 630).

RESULTS

We identified four different USP8-mutations previously described, in 11 out of 47 (23.4%) corticotropinomas; 8 out of 11 were MACs. The urinary cortisol levels of our patients with corticotrophin USP8-mutated-alleles were lower than those of patients with wild-type (WT) alleles (p ≤ 0.017). The frequency of USP8-mutated-alleles among the series was approximately 30% with a higher prevalence in female-patients (p < 0.1 × 10^-4). Among the 5 series, the remission rates were higher in patients with USP8-mutated-alleles than in those with the USP8-WT-alleles (p < 0.1 × 10^-4).

CONCLUSION

Our data, as well as the retrospective review of CD series associated with USP8-mutated alleles, show heterogeneous findings among the series. Several drawbacks included the lack of a systematic protocol to evaluate these patients before surgery and follow-up. Further prospective studies using a systematic protocol will provide more consistent information about the influence of the corticotropinomas with USP8-mutated alleles on the phenotype, responses to treatment and outcome of patients with CD.

Filamin A and DRD2 expression in corticotrophinomas

PURPOSE

Filamin A (FLNA) expression is related to dopamine receptor type 2 (DRD2) expression in prolactinomas. Nevertheless, in corticotrophinomas, there are few studies about DRD2 expression and no data on FLNA. Therefore, we evaluated FLNA and DRD2 expression in corticotrophinomas and their association with tumor characteristics.

METHODS

DRD2 and FLNA expression by immunohistochemistry, using H-score, based on the percentage of positive cells in a continuous scale of 0-300, were evaluated in 23 corticotrophinomas samples from patients submitted to neurosurgery. In six patients, treatment with cabergoline was indicated after non curative surgery.

RESULTS

Twenty-two patients were female and one male. Regarding tumor size, 10 were micro and 12 were macroadenomas. DRD2 expression was found in 89% of cases and did not correlate with FLNA expression. Moreover, the response to cabergoline, observed in 33% of the cases, did not correlate with DRD2 nor FLNA expression. FLNA expression was not associated with clinical and tumor characteristics, except for sphenoid sinus invasion.

CONCLUSIONS

In our cohort of corticotrophinomas, DRD2 expression was not associated with FLNA expression nor to the response to CAB. Nonetheless, FLNA expression could be related to tumor invasiveness.

Study of major genetic factors involved in pituitary tumorigenesis and their impact on clinical and biological characteristics of sporadic somatotropinomas and non-functioning pituitary adenomas

Genetic and functional aberrations of guanine nucleotide-binding protein, alpha stimulating (GNAS), aryl hydrocarbon receptor interacting protein (AIP), and pituitary tumor transforming gene (PTTG) are among the most prominent events in pituitary tumorigenesis. A cohort of Brazilian patients with somatotropinomas (n=41) and non-functioning pituitary adenomas (NFPA, n=21) from a single tertiary-referral center were evaluated for GNAS and AIP mutations and gene expression of AIP and PTTG. Results were compared to the clinical and biological (Ki67 and p53 expression) characteristics of tumors and their response to therapy, if applicable. Genetic analysis revealed that 27% of somatotropinomas and 4.8% of NFPA harbored GNAS mutations (P=0.05). However, no differences were observed in clinical characteristics, tumor extension, response to somatostatin analog therapy, hormonal/surgical remission rates, Ki67 index, and p53 expression between mutated and non-mutated somatotropinomas patients. PTTG overexpression (RQ mean=10.6, min=4.39, max=11.9) and AIP underexpression (RQ mean=0.56, min=0.46-max=0.92) were found in virtually all cases without a statistically significant relationship with clinical and biological tumor features. No patients exhibited somatic or germline pathogenic AIP mutations. In conclusion, mutations in GNAS and abnormal PTTG and AIP expression had no impact on tumor features and treatment outcomes in this cohort. Our data support some previous studies and point to the need for further investigations, probably involving epigenetic and transcriptome analysis, to improve our understanding of pituitary tumor behavior.

Intracranial germinoma causing cerebral haemiatrophy and hypopituitarism

A young woman presented with primary amenorrhoea, progressive haemiparesis, visual disturbance, dementia and focal motor seizures. Investigations showed hypopituitarism, unilateral cerebral atrophy and inflamed cerebrospinal fluid. A trans-sphenoidal biopsy gave a unifying diagnosis of a pituitary germinoma.