Basic and clinical research progress in pulmonary alveolar microlithiasis / 医学研究生学报

Pulmonary alveolar microlithiasis (PAM) is a rare genetic disease characterized by calcifications within the alveoli in the lung. Mutations in SLC34A2 gene, which encodes a type IIb sodiumphosphate cotransporter, are responsible for PAM, leading to the intra-alveolar accumulation of phosphate which favors the formation of microliths. A "sandstorm" appearance is the typical radiographic presentation of PAM. The hallmark of this disorder is clinical-radiological dissociation, with typical imaging findings, specific pathological findings and closely correlated specific genetic mutations. The disease has an insidious onset, runs a chronic course and the prognosis is poor. There is no effective treatment except for lung transplantation. This article summarizes the epidemiology, molecular genetics and clinical features of pulmonary alveolar calculi.

A case report of pulmonary alveolar microlithiasis / 基础医学与临床

Objective To report a case of pulmonary alveolar microlithiasis ( PAM) in Peking Union Medical Col-lege Hospital and to summarize the clinical features and genetic characters .Methods The clinical features , ima-ging results , pathology findings and SLC34 A2 gene mutation was analyzed and reported .Results The patient was a 35 years old male, presenting with cough and sputum for 10 years and worsen with short of breath for 3 weeks. Computed tomography of lung and pathology findings support the diagnose of pulmonary alveolar microlithiasis .And a heterozygous mutation c .A910 T in exon 8 of SLE34 A2 gene was discovered through genetic testing .Conclusions Since to the treatment is non-specific in this rare disease , it's significantly important to recognize this disease through early non-specific clinical features but typical imaging findings .And the finding that c .A910 T is more common in Asia population may provide us a potential target for screening and possible genetic engineering therapy .

Pulmonary Alveolar Microlithiasis in an Elderly: A Case Report with Brief Review of Literature.

Pulmonary alveolar microlithiasis (PAM) is a rare chronic lung disease characterized by presence of widespread intraalveolar accumulation of innumerable minute calculi called microliths. It is caused by inactivating mutations in the gene “solute carrier family 34 member 2”, encoding a sodium-dependent phosphate co-transporter (SLC34A2) expressed primarily in alveolar epithelial type II cells. It is most frequently diagnosed from birth to 40 years of age with a mean age of 27-30 years at the time of diagnosis. Most of patients are asymptomatic or having mild symptoms and are usually diagnosed incidentally. Chest radiograph and high-resolution CT of thorax are nearly pathognomonic for diagnosing PAM and histopathological confirmation is required only in few cases. This disease has slow progressive course ultimately leading to death by causing pulmonary fibrosis and cor pulmonale. Currently, there is no medical or gene therapy capable of reducing disease progression. Lung transplantation remains the only possible treatment for end-stage disease. Herein,we report a case of PAM in a 60-year-old gentleman who presented with a 5-year history of shortness of breath on exertion and intermittent cough with expectoration. His sister had similar respiratory symptoms and died 10 years back of which no details are available. The rarity of this disease and late age of presentation prompted us to report this case.

Pulmonary alveolar microlithiasis / Microlitiasis alveolar pulmonar

Pulmonary alveolar microlithiasis is an uncommon disease of unknown etiology, and is characterized by the presence of multiple sub-pleural and intra-alveolar microcalcifications. We present the case of a patient with rheumatoid arthritis and chronic renal disease, but with no respiratory symptoms.

La microlitiasis pulmonar alveolar es una enfermedad infrecuente, de etiología desconocida, caracterizada por la presencia de múltiples microcalcificaciones intraalveolares y subpleurales. Presentamos el caso de un paciente asintomático respiratorio, con historia clínica de artritis reumatoide y enfermedad renal crónica.

Can chest high-resolution computed tomography findings diagnose pulmonary alveolar microlithiasis? / Podem os achados na tomografia computadorizada de alta resolução do tórax ser diagnósticos de microlitíase alveolar pulmonar?

AbstractObjective:The present study was aimed at retrospectively reviewing high-resolution computed tomography (HRCT) findings in patients with pulmonary alveolar microlithiasis in order to evaluate the frequency of tomographic findings and their distribution in the lung parenchyma.Materials and Methods:Thirteen patients (9 females and 4 males; age, 9 to 59 years; mean age, 34.5 years) were included in the present study. The HRCT images were independently evaluated by two observers whose decisions were made by consensus. The inclusion criterion was the presence of abnormalities typical of pulmonary alveolar microlithiasis at HRCT, which precludes lung biopsy. However, in 6 cases lung biopsy was performed.Results:Ground-glass opacities and small parenchymal nodules were the predominant tomographic findings, present in 100% of cases, followed by small subpleural nodules (92.3%), subpleural cysts (84.6%), subpleural linear calcifications (69.2%), crazy-paving pattern (69.2%), fissure nodularity (53.8%), calcification along interlobular septa (46.2%) and dense consolidation (46.2%).Conclusion:As regards distribution of the lesions, there was preferential involvement of the lower third of the lungs. No predominance of distribution in axial and anteroposterior directions was observed.

ResumoObjetivo:Analisar, retrospectivamente, as tomografias computadorizadas de alta resolução (TCAR) de pacientes com microlitíase alveolar pulmonar, a fim de avaliar a frequência dos padrões tomográficos e sua distribuição no parênquima pulmonar.Materiais e Métodos:O estudo incluiu 13 pacientes (9 femininos e 4 masculinos) com idades variando de 9 a 59 anos (média de 34,5 anos). Os exames foram avaliados por dois observadores, de modo independente, e os casos discordantes, resolvidos por consenso. O critério de inclusão foi a presença de anormalidades na TCAR típicas de microlitíase alveolar pulmonar, o que prescinde a necessidade de exame histopatológico. Entretanto, em 6 casos foram realizadas biópsias pulmonares.Resultados:Os achados tomográficos predominantes foram opacidades em vidro fosco e pequenos nódulos parenquimatosos, presentes em 100% dos casos, seguidos de pequenos nódulos subpleurais (92,3%), cistos subpleurais (84,6%), calcificações lineares subpleurais (69,2%), padrão de pavimentação em mosaico (69,2%), fissura nodular (53,8%), calcificação ao longo dos septos interlobulares (46,2%) e consolidações densas (46,2%).Conclusão:Quanto à distribuição dos achados, houve acometimento preferencial dos terços inferiores. Não foi observado predomínio de distribuição dos sentidos axial e anteroposterior.

Microlitiasis alveolar pulmonar: caso clínico / Pulmonary alveolar microlithiasis: Report of one case

Pulmonary alveolar microlithiasis is an extremely rare disease characterized by intra-alveolar accumulation of calcified spherical particles (called microliths), due to a mutation of the gene encoding a membrane transport protein of the alveolar surface. Most patients are asymptomatic at diagnosis. The course of the disease is slowly progressive, with development of pulmonary fibrosis and respiratory failure. The "sandstorm" pattern is the characteristic finding of this disease. We report a 39-year-old female presenting with progressive dyspnea. A chest X ray showed ground-glass opacities and a high resolution CT scan showed numerous calcified lung micronodules. A surgical lung biopsy confirmed the diagnosis of pulmonary alveolar microlithiasis.

Pulmonary Alveolar Microlithiasis: A Clinicoradiological Dissociation.

Pulmonary alveolar microlithiasis (PAM) is a rare and slowly progressive disease characterized by widespread calcification within the alveoli with a paucity of symptoms in contrast to radiologic findings. We report here a case of pulmonary alveolar microlithiasis who presented to us with minimal chest complaints following chest trauma despite extensive imaging findings.

Sandstorm Appearance of Pulmonary Alveolar Microlithiasis Incidentally Detected in a Young, Asymptomatic Male

Pulmonary alveolar microlithiasis (PAM) is a rare chronic disease with paucity of symptoms in contrast to the imaging findings. We present a case of a 24-year-old Malay man having an incidental abnormal pre-employment chest radiograph of dense micronodular opacities giving the classical "sandstorm" appearance. High-resolution computed tomography of the lungs showed microcalcifications with subpleural cystic changes. Open lung biopsy showed calcospherites within the alveolar spaces. The radiological and histopathological findings were characteristic of PAM.