Non-invasive follicular neoplasm with papillary-like nuclear features: a challenging and infrequent entity in Argentina.

PURPOSE: Non-invasive encapsulated follicular variant of papillary thyroid cancer was reclassified as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). These neoplasms have an extremely low malignant potential. The aim of this study was (1) to assess the prevalence of NIFTP in patients with papillary thyroid carcinoma, (2) to evaluate their outcomes, and (3) to determine their molecular profile. METHODS: Multicenter, descriptive, retrospective study. Patients with papillary thyroid cancer diagnosed from January 2006 to December 2016 from 11 referral centers were included. Diagnosis of NIFTP was based on criteria described by Nikiforov et al. in 2018. At least two pathologists agreed on the diagnosis. Two thousand six hundred and seventy-seven papillary thyroid cancer patients were included; 456 (17%) of them were follicular variant papillary thyroid cancer, and 30 (1.12%) fulfilled diagnostic criteria for NIFTP. RESULTS: Each of the 30 included patients underwent a total thyroidectomy, and 50% were treated with radioiodine (median dose 100 mCi). After a median follow-up of 37 months, 84% of patients had an excellent response, 3% had an indeterminate response and data was missing in the remaining 13%. No metastatic lymph nodes, distant metastases or recurrences were found. RAS mutations were detected in 4 patients (13%). CONCLUSION: The prevalence of NIFTP in our series is amongst the lowest reported. Excellent outcomes of patients underscore their low malignant potential. Molecular findings differ from other series, probably related to environmental or ethnic features of our population and the meticulous criteria for diagnosing NIFTP.

Clinical and molecular characterization of mitochondrial DNA disorders in a group of Argentinian pediatric patients.

OBJECTIVE: To describe the clinical and molecular features of a group of Argentinian pediatric patients with mitochondrial DNA (mtDNA) disorders, and to evaluate the results of the implementation of a classical approach for the molecular diagnosis of mitochondrial diseases. METHODS: Clinical data from 27 patients with confirmed mtDNA pathogenic variants were obtained from a database of 89 patients with suspected mitochondrial disease, registered from 2014 to 2020. Clinical data, biochemical analysis, neuroimaging findings, muscle biopsy and molecular studies were analyzed. RESULTS: Patients were 18 females and 9 males, with ages at onset ranging from 1 week to 14 years (median = 4 years). The clinical phenotypes were: mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome (n = 11), Leigh syndrome (n = 5), Kearns-Sayre syndrome (n = 3), Chronic Progressive External Ophthalmoplegia (n = 2), Leber hereditary optic neuropathy (n = 2), myoclonic epilepsy associated with ragged-red fibers (n = 1) and reversible infantile myopathy with cytochrome-C oxidase deficiency (n = 3). Most of the patients harbored pathogenic single nucleotide variants, mainly involving mt-tRNA genes, such as MT-TL1, MT-TE and MT-TK. Other point variants were found in complex I subunits, like MT-ND6, MT-ND4, MT-ND5; or in MT-ATP6. The m.13513G > A variant in MT-ND5 and the m.9185 T > C variant in MT-ATP6 were apparently de novo. The rest of the patients presented large scale-rearrangements, either the "common" deletion or a larger deletion. CONCLUSIONS: This study highlights the clinical and genetic heterogeneity of pediatric mtDNA disorders. All the cases presented with classical phenotypes, being MELAS the most frequent. Applying classical molecular methods, it was possible to achieve a genetic diagnosis in 30% of the cases, suggesting that this is an effective first approach, especially for those centers from low-middle income countries, leaving NGS studies for those patients with inconclusive results.

HNRNPDL-related muscular dystrophy: expanding the clinical, morphological and MRI phenotypes.

Autosomal dominant limb girdle muscular dystrophy D3 HNRNPDL-related is a rare dominant myopathy caused by mutations in HNRNPDL. Only three unrelated families have been described worldwide, a Brazilian and a Chinese carrying the mutation c.1132G>A p.(Asp378Asn), and one Uruguayan with the mutation c.1132G>C p. (Asp378His), both mutations occurring in the same codon. The present study enlarges the clinical, morphological and muscle MRI spectrum of AD-HNRNPDL-related myopathies demonstrating the significant particularities of the disease. We describe two new unrelated Argentinean families, carrying the previously reported c.1132G>C p.(Asp378His) HNRNPDL mutation. There was a wide phenotypic spectrum including oligo-symptomatic cases, pure limb girdle muscle involvement or distal lower limb muscle weakness. Scapular winging was the most common finding, observed in all patients. Muscle MRIs of the thigh, at different stages of the disease, showed particular involvement of adductor magnus and vastus besides a constant preservation of the rectus femoris and the adductor longus muscles, defining a novel MRI pattern. Muscle biopsy findings were characterized by the presence of numerous rimmed vacuoles, cytoplasmic bodies, and abundant autophagic material at the histochemistry and ultrastructural levels. HNRNPDL-related LGMD D3 results in a wide range of clinical phenotypes from the classic proximal form of LGMD to a more distal phenotype. Thigh MRI suggests a specific pattern. Codon 378 of HNRNPDL gene can be considered a mutation hotspot for HNRNPDL-related myopathy. Pathologically, the disease can be classified among the autophagic rimmed vacuolar myopathies as with the other multisystem proteinopathies.

[Pulmonary tumorlet associated with second neoplasia]. / Asociación de tumorlet pulmonar con segundas neoplasias.

Tumorlets are pulmonary neuroendocrine tumors smaller than 0.5 cm. They are benign and usually asymptomatic. Their diagnosis is important so as to differentiate them from other neuroendocrine pathologies that require therapeutic intervention. We report a case of such entity and a discussion on the subject that can contribute to highlight the importance of diagnosing this entity.

Asociación de tumorlet pulmonar con segundas neoplasias / Pulmonary tumorlet associated with second neoplasia

Los tumorlets son tumores neuroendocrinos pulmonares menores a 0.5 cm, de evolución benigna y habitualmente asintomáticos. Su diagnóstico es importante para realizar la diferenciación con otras afecciones neuroendocrinas y enfermedad metastásica de otro origen, que requerirán una intervención terapéutica. Se presenta un caso de dicha entidad asociada a otros tumores.

Tumorlets are pulmonary neuroendocrine tumors smaller than 0.5 cm. They are benign and usually asymptomatic. Their diagnosis is important so as to differentiate them from other neuroendocrine pathologies that require therapeutic intervention. We report a case of such entity and a discussion on the subject that can contribute to highlight the importance of diagnosing this entity.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) in Argentina.

CADASIL is the most common cause of hereditary stroke and vascular dementia. Published information about this disease in South America is scant. We describe clinical and demographic characteristics of 13 patients (10 families) with CADASIL from Argentina.Methods Medical records, diagnostic tests and family history of patients with CADASIL were reviewed.Results Thirteen patients with CADASIL (10 families) were included. All patients had European ancestry. Initial presentation was stroke in most patients (n = 11). Stroke patients later developed cognitive complaints (n = 9), migraine with aura (n = 1), apathy (n = 4) and depression (n = 6). External capsule and temporal lobe involvement on MRI were characteristic imaging findings. Two patients died after intracerebral hemorrhage.Conclusion This is the first report of non-related patients with CADASIL in South America addressing ancestry. Since European ancestry is not highly prevalent in all South American countries, there may be variable incidence of CADASIL within this region.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) in Argentina / Arteropatia cerebral autosomal dominante com infartos subcorticais e leucoencefalopatia (CADASIL) na Argentina

CADASIL is the most common cause of hereditary stroke and vascular dementia. Published information about this disease in South America is scant. We describe clinical and demographic characteristics of 13 patients (10 families) with CADASIL from Argentina.Methods Medical records, diagnostic tests and family history of patients with CADASIL were reviewed.Results Thirteen patients with CADASIL (10 families) were included. All patients had European ancestry. Initial presentation was stroke in most patients (n = 11). Stroke patients later developed cognitive complaints (n = 9), migraine with aura (n = 1), apathy (n = 4) and depression (n = 6). External capsule and temporal lobe involvement on MRI were characteristic imaging findings. Two patients died after intracerebral hemorrhage.Conclusion This is the first report of non-related patients with CADASIL in South America addressing ancestry. Since European ancestry is not highly prevalent in all South American countries, there may be variable incidence of CADASIL within this region.

CADASIL é a causa mais frequente de acidente vascular cerebral e demência hereditários. São poucas as publicações sobre esta doença na América do Sul. Aqui descrevemos dados clínicos e demográficos de 13 pacientes (10 famílias) da Argentina com CADASIL.Métodos Prontuários médicos testes diagnósticos e história familiar de pacientes com CADASIL foram revisados.Resultados Treze pacientes com CADASIL (10 famílias) foram incluídos. Todos os pacientes tinha ancestralidade europeia. A apresentação inicial foi acidente vascular cerebral na maioria dos pacientes (n = 11). Pacientes com acidente vascular cerebral depois desenvolveram alterações cognitivas (n = 9), enxaqueca com aura (n = 1), apatia (n = 4) e depressão (n = 6). Os achados de imagem característicos da RM foram na cápsula externa e no lobo temporal. Dois pacientes morreram por hemorragia intracerebral.Conclusão Este é o primeiro relato de série de casos de pessoas não relacionadas entre si que apresentavam CADASIL na América do Sul, discutindo ancestralidade. Uma vez que a ascendência europeia tem prevalência variada em diferentes países da América do Sul, é possível que esta seja uma variável de incidência de CADASIL nesta região.

Tumor cell lines resistant to ALA-mediated photodynamic therapy and possible tools to target surviving cells.

We isolated and characterized cell lines resistant to aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) derived from a murine adenocarcinoma and studied cross resistance with other injuries. The most resistant clones were numbers 4 and 8, which exhibited 6.7- and 4.2-fold increase in resistance respectively. Several characteristics were altered in these clones. A 2-fold increase in cell volume, higher cell spreading, and a more fibroblastic, dendritic pattern, were the morphology features that led us to think they could have different adhesive, invasive or metastatic phenotypes. The amount of porphyrins synthesized per cell in the resistant clones was similar to the parental line but, when it was expressed per mg protein, there was a 2-fold decrease, with a higher proportion of hydrophilic porphyrins. These cells were not cross-resistant to photosensitization with Benzoporphyrin derivative and Merocyanine 540, but exhibited a slight resistance to exogenous protoporphyrin IX treatment. Both clones displayed higher protein content and increased number of mitochondria, together with a higher oxygen consumption. The distinctive features found in the resistant lines led as to think how to exploit the changes induced by PDT treatment to target surviving cells. Those hypoxic cells can be also a preferential target of bioreductive drugs and hypoxia-directed gene therapy, and would be sensitive to treatment with other photosensitizers.

Hiperplasia gigante de ganglios linfáticos (enfermedad de Castleman) con neuropatía periférica y síndrome de secreción inadecuada de hormona antidiurética / Giant lymph node hyperplasia (Castleman's disease) with peripheral nerve diseases and syndrome of inappropriate secretion of antidiuretic hormone

Se presenta un caso clínico de enfermedad de Castleman localizada en el mediastino simulando um timoma. Castleman describió por primera vez la hiperplasia gigante de ganglios linfáticos. Esta entidad presenta dos tipos histopatológicos con formas de transición entre ambos. Son destacables los síntomas y signos de neuropatía periférica. Como hecho original encontramos asociado un síndrome de secreción inadecuada de hormona antidiurética que cede totalmente con la extirpación del tumor. La histología demostró una hiperplasia gigante de ganglios linfáticos tipo II (hialino-vascular) con formación de seudo-corpúsculos de Hassall

Hiperplasia gigante de ganglios linfáticos (enfermedad de Castleman) con neuropatía periférica y síndrome de secreción inadecuada de hormona antidiurética / Giant lymph node hyperplasia (Castlemans disease) with peripheral nerve diseases and syndrome of inappropriate secretion of antidiuretic hormone

Se presenta un caso clínico de enfermedad de Castleman localizada en el mediastino simulando um timoma. Castleman describió por primera vez la hiperplasia gigante de ganglios linfáticos. Esta entidad presenta dos tipos histopatológicos con formas de transición entre ambos. Son destacables los síntomas y signos de neuropatía periférica. Como hecho original encontramos asociado un síndrome de secreción inadecuada de hormona antidiurética que cede totalmente con la extirpación del tumor. La histología demostró una hiperplasia gigante de ganglios linfáticos tipo II (hialino-vascular) con formación de seudo-corpúsculos de Hassall (AU)