Rare and unknown canine systemic mastocytosis: clinical and laboratory features of an aberrant c-Kit mutation neoplasia / A rara e desconhecida mastocitose sistêmica canina: características clínicas e laboratoriais de uma neoplasia aberrante na mutação c-Kit

Systemic mastocytosis (SM) pathology is extremely rare in canine practice, with insufficient reported data. The knowledge of the clinical behavior of this pathology is scarce. In human medicine, SM has been widely investigated, being defined as a rare hematopoietic disorder by the World Health Organization (2016), within the type of myeloproliferative neoplasms. Herein, we describe a systemic mastocytosis case in a Portuguese Serra-da-Estrela dog, where a cutaneous grade III/high-grade MCT was also diagnosed. The clinical decline of the animal and owner's insistence throughout anamnesis that the dog was markedly different after the cytologic exam performed in another clinic, along with both severe eosinophilia and hepatomegaly, led to the clinical suspicion of SM. The animal passed away 7 days later. Post-morteminvestigation confirmed SM pathology, and a deletion of 15 base pairs change on c-Kit gene exon 11 was identified. Contemplating the low number of cases described in the literature, this publication aims to disclose clinical and laboratory features of rare and poorly described canine SM, taking into consideration human outcomes described in the literature.(AU)

A patologia da mastocitose sistêmica (SM) é extremamente rara na prática clínica canina, com escassos casos descritos na literatura científica. O conhecimento do comportamento clínico desta patologia é mínimo. Na medicina humana, a SM tem sido amplamente investigada, sendo definida como uma doença hematopoiética rara pela Organização Mundial da Saúde (2016), dentro do tipo de neoplasias mieloproliferativas. Descrevemos aqui um caso de mastocitose sistêmica num cão Serra-da-Estrela português, diagnosticado também com um mastocitoma cutâneo grau III / alto grau. O declínio clínico do animal e a insistência do proprietário durante a anamnese de que o cão estava marcadamente diferente após o exame citológico realizado em outra clínica, juntamente com eosinofilia e hepatomegalia graves, levantaram a suspeita clínica de SM. O animal faleceu 7 dias depois. A investigação post-mortem confirmou a patologia SM, e o estudo molecular revelou uma deleção de 15 pares de bases no exon 11 do gene c-Kit. Contemplando o baixo número de casos descritos na literatura, o objetivo desta publicação é divulgar características clínicas e laboratoriais de SM canina, levando em consideração informações clínicas descritas em humanos.(AU)

Compromiso óseo en mastocitosis sistémica: una asociación frecuente, pero muchas veces inadvertida / Bone involvement in systemic mastocytosis: report of two cases

Systemic mastocytosis (SM) is characterized by pathologic expansion and activation of mast cells. The main clinical manifestations of SM include skin involvement, gastrointestinal symptoms and anaphylaxis due to the release of its mediators. Thirty percent of pat ients with SM have a low bone mass and 20% fractures. At the same time, SM affects 10% of male patients with idiopathic osteoporosis. Measuring serum tryptase is essential for the screening of MS. We report two cases of SM with bone involvement. A 25-year- old woman with prior diagnosis of SM, based on skin involvement, flushing, high serum tryptase and compatible bone marrow (BM) biopsy and genetic study. Low bone mass was diagnosed and treatment was started with calcium and vitamin D plus oral bisphosphona tes with adequate response. A 47 years old man who presented with multiple osteoporotic vertebral fractures and low bone mass. Treatment with vitamin D and alendronate was started, but the patient developed new vertebral fractures. The study was extended w ith measurement of serum tryptase that was elevated. Diagnosis of SM was confirmed with BM biopsy and the patient was referred to hematology for specific care. These cases emphasize the importance of bone assessment in SM, as well as the need to rule out S M in patients with osteoporosis and no evident cause.

Indolent systemic mastocytosis limited to the bone: a case report and review of the literature / Mastocitose sistemica indolente restrita ao osso: um relato de caso e revisao da literatura

CONTEXT Systemic mastocytosis is defined as a clonal disorder of mast cells and their precursor cells and is currently classified as a myeloproliferative neoplasm. Its clinical course has a wide spectrum, ranging from indolent disease, with normal life expectancy, to highly aggressive disease, associated with multisystemic involvement and poor overall survival. The aim of this study was to report a case of indolent systemic mastocytosis, focusing on the diagnostic challenges, with a review of the literature. CASE REPORT A 79-year-old Caucasian woman with osteoporosis was evaluated at the Emergency Department because of complaints of low back pain. Before this, she had consulted an orthopedist and had undergone some imaging examinations, namely a bone scan that revealed a “superscan” pattern. Due to her pain complaints and these test results, the patient was admitted to the Department of Internal Medicine. After undergoing several analytical tests and some additional imaging examinations to rule out some important differential diagnoses, she then underwent bone marrow biopsy, which made it possible to identify indolent systemic mastocytosis. CONCLUSION Systemic mastocytosis is a rare entity that is difficult to diagnose. Its symptoms are often unspecific and frequently ignored. Skeletal changes may be the first and only manifestation of the disease and in some cases, like this one, the diagnosis is made only after histological examination. The key point for the diagnosis is to contemplate the possibility of systemic mastocytosis. .

CONTEXTO A mastocitose sistêmica é definida como um distúrbio clonal do mastócito e suas células precursoras, sendo atualmente classificada como uma neoplasia mieloproliferativa. Seu curso clínico tem um espectro alargado, variando desde a doença indolente caraterizada por uma sobrevida normal, até a doença altamente agressiva associada a um envolvimento multissistêmico e a uma sobrevida reduzida. Este artigo reporta um caso de mastocitose sistêmica indolente, focando as principais dificuldades diagnósticas e fazendo uma revisão sistematizada da literatura. RELATO DO CASO Mulher de 79 anos, caucasiana, com antecedentes de osteoporose, foi avaliada no Serviço de Urgência por queixas de dor lombar. Antes disso, a doente havia consultado um ortopedista e realizado alguns exames de imagem, nomeadamente uma cintilografia óssea, que revelou um padrão em “superscan”. Em virtude de suas queixas álgicas e dos resultados dos estudos efetuados, foi internada no Departamento de Medicina Interna. Depois de realizados vários estudos analíticos e exames de imagem suplementares para excluir algumas importantes hipóteses de diagnóstico, a doente fez uma biópsia de medula óssea que permitiu identificar uma mastocitose sistêmica indolente. CONCLUSÃO A mastocitose sistêmica é uma entidade rara e difícil de diagnosticar. Os seus sintomas são muitas vezes inespecíficos e frequentemente ignorados. As alterações esqueléticas podem ser as primeiras e as únicas manifestações e, em certos casos, como este, o diagnóstico só pode ser feito após exame histológico. O mais importante para o diagnóstico é contemplar a hipótese de estarmos perante uma mastocitose sistêmica. .

Acute myeloid leukemia (AML-M2) with mast cell hyperplasia of bone marrow: a report of three cases.

Bone marrow mastocytosis, though infrequently documented in Indian patients, may be observed in association with many non mast cell hematological neoplasms, including acute myeloblastic leukemia (AML) and myelodysplastic syndromes (MDS). We report three cases of acute myeloid leukemia with excess of mast cells in the bone marrow (BM) samples. Mast cell hyperplasia may remain under diagnosed due to shortcoming of morphological identification and diagnostic workup.