Lung India

CASE REPORT
Year
: 2014  |  Volume : 31  |  Issue : 3  |  Page : 293--295

A 55 years old man with pulmonary alveolar microlithiasis


Rebeen R Saeed1, Kosar M Ali2,  
1 Department of Medicine, General University Teaching Hospital of Sulaimania, Kurdistan, Iraq
2 Department of Medicine, General University Teaching Hospital of Sulaimania; Department of Medicine, School of Medicine, University of Sulaimania, Kurdistan, Iraq

Correspondence Address:
Dr. Rebeen R Saeed
Department of Medicine, University Teaching Hospital of Slemani, PO Box - 409 Kurdistan
Iraq

Abstract

Pulmonary alveolar microlithiasis (PAM) is a very rare diffuse chronic lung disease characterized by deposition of small spherules of calcium phosphate within the alveolar cavity. The disease is usually seen from birth up to 40 years of age and is usually diagnosed incidentally during radiography of the chest for other reasons. Most of patients are asymptomatic or having very mild symptoms and the majority of patients either have normal or restrictive pulmonary function test. Clinically, the course of the disease is different; it remains static in few patients or it may progress to pulmonary fibrosis, respiratory failure and cor pulmonale in others. In this case report, we present a 55-year-old man who presented with moderate shortness of breath which has progressed from mild symptoms with in the previous years. His chest high-resolution CT scan showed diffusely scattered, ill-defined little shadowy micronodules which involve the left lung; lingula and left lower lobe in particular. A lung biopsy confirmed the diagnosis of PAM. He was followed up for 1 year with treatment by steroid and alendronate, and no progression was noticed in fact improvement in pulmonary function test noticed. This is the first case report of PAM in Kurdistan.



How to cite this article:
Saeed RR, Ali KM. A 55 years old man with pulmonary alveolar microlithiasis.Lung India 2014;31:293-295


How to cite this URL:
Saeed RR, Ali KM. A 55 years old man with pulmonary alveolar microlithiasis. Lung India [serial online] 2014 [cited 2019 Dec 14 ];31:293-295
Available from: http://www.lungindia.com/text.asp?2014/31/3/293/135786


Full Text

 Introduction



Pulmonary alveolar microlithiasis (PAM) is a very rare diffuse and chronic lung disease, characterized by the presence or deposition of small spherical calcium phosphate bodies containing concentric calcareous lamellas in pulmonary alveoli. [1],[2],[3],[4] It was first named in 1933 by Puhr. [5] Although the etiology still remains not clear, PAM is considered to have an autosomal recessive pattern caused by mutations of the solute carrier family 34 (sodium phosphate), member 2 gene (the SLC34A2 gene), which encodes a sodium phosphate cotransporter. [6],[7]

 Case Report



A 55-year-old man presented to our department with moderate to severe shortness of breath and dry cough that had worsened over the previous few years. Initially he became short of breath during moderate exertion and later he had shortness of breath even at rest. He denied having any history of recent respiratory tract infection and old chronic infections like tuberculosis. Furthermore, he had a slight cough with minimal sputum production. He has never smoked. He did not have history of any chronic drug use or any chronic medical problems apart from the shortness of the breath. He denied contact with any animal or bird.

Vitals were within normal range, he had coarse crackles mainly at the basal and middle zone of the left lung. The hemoglobin, total and differential white cell counts were within normal range. A full blood count revealed an elevated erythrocyte count of 6.05 × 10 6 ml -1 and Hematocrit 55%. Arterial blood gas analysis values in room air were: pH: 7.43, PaO 2 : 51 mmHg, PaCO 2 : 29 mmHg, HCO 3 : 16 mmol l -1 and O 2 saturation 87%. Pulmonary function tests revealed typical features of a restrictive defect with a reduced total lung capacity of 56% and vital capacity of 46%, and a forced expiratory volume in 1 s/forced vital capacity (FEV 1 /FVC):100. Echocardiography showed severe pulmonary hypertension, 82 mmHg, a dilated right heart and moderate tricuspid regurgitation. Liver and renal function tests were also within reference limits. Serum calcium and phosphate levels were normal. Moreover, skin tests for tuberculosis and studies for acid-fast bacilli were negative and also there was negative urinalysis. Additionally, the inflammatory markers like ESR, CRP and even Ferritin were within normal range. The plain chest X-ray films revealed a diffuse symmetric dense, micronodular (''sand-storm'') pattern mainly on the left side [Figure 1]. A high-resolution CT (HRCT) scan was obtained in the supine position at maximal inspiration at 10 mm intervals. All scans were photographed with window/level settings of 770/10, 1730/2810 and 1910/2500 Hounsfield Units. The examination showed diffuse symmetric lung abnormalities characterized by ground-glass attenuation and septal thickening with calcified nodules, resulting in a crazy-paving pattern. Subpleural calcification was also seen [Figure 2]a and b. Bronchoscopy and BAL were unremarkable. The patient had a transbronchial lung biopsy and histology revealed round, concentrically laminated microliths in the alveoli, which were periodic acid-Schiff (PAS) positive in keeping with the diagnosis of PAM. He was treated with Alendronate 70 mg once weekly, steroid initially as prednisolone 30 mg/day reduced over a month to 10 mg/day, with further reduction over coming months until we stopped it completely and the total duration for steroid use was 1 year, he is still on alendronate. Furthermore, with the current treatment his PFT (FEV 1 and VC) improved by 10% after a year of treatment.{Figure 1}{Figure 2}



The main feature of PAM is widespread laminated calcipherites in the alveolar spaces in the absence of any known disorder of calcium metabolism. [8],[9] Patients may remain asymptomatic for many years and do usually become symptomatic between the third and fourth decades. [8],[10],[11] The clinical presentation usually illustrate a restrictive pattern of lung disease as seen in our patient. [8],[10] In the early course of the disease pneumothorax may be observed. Adult patients commonly show progressive deterioration of the pulmonary function and death usually occurs in mid-life because of respiratory failure associated with cor pulmonale. [8],[12] The chest radiograph usually shows small innumerable, widespread, and calcified nodules, which tend to be more at the base. HRCT scan has assisted in characterization of the imaging of the disease and can be beneficial in diagnosis. Ground-glass opacities due to volume averaging of tiny microliths are a common and major finding in the literature. Subpleural linear calcification and nodular fissural thickening are also usual findings. [9],[10],[13],[14]

Although the imaging can help in diagnosing the disease but the lung biopsy is the best for definitive diagnosis. [14] Furthermore, Sahoo et al. recommend that (18) F-sodium fluoride PET/CT is a superior modality in characterization and assessment of the extent of disease in PAM compared to all other non-invasive imaging modalities thus (18) F-sodium fluoride PET/CT should be the investigation of choice in PAM. [15]

There is no known effective treatment for PAM, with the exception of lung transplantation. [16] To our knowledge, recurrence of the disease after lung transplantation has not been reported. Observational studies have found therapeutic BAL to be ineffective, [17],[18],[19] except for symptomatic improvement in one case, without improvement in conventional pulmonary radiography and HRCT. [20] Corticosteroids are generally considered to be ineffective. However, only a few authors have reported on the effect of corticosteroids. [7]

References

1Castellana G, Lamorgese V. Pulmonary alveolar microlithiasis. World cases and review of the literature. Respiration 2003;70:549-55.
2Lauta VM. Pulmonary alveolar microlithiasis: An overview of clinical and pathological features together with possible therapies. Respir Med 2003;97:1081-5.
3Mariotta S, Ricci A, Papale M, De Clementi F, Sposato B, Guidi L, et al. Pulmonary alveolar microlithiasis: Report on 576 cases published in the literature. Sarcoidosis Vasc Diffuse Lung Dis 2004;21:173-81.
4Chan ED, Morales DV, Welsh CH, McDermott MT, Schwarz MI. Calcium deposition with or without bone formation in the lung. Am J Respir Crit Care Med 2002;165:1654-69.
5Puhr L. Mikrolithiasis alveolaris pulmonum. Virchows Arch Pathol Anat 1933;290:156-60.
6Corut A, Senyigit A, Ugur SA, Altin S, Ozcelik U, Calisir H, et al. Mutations in SLC34A2 cause pulmonary alveolar microlithiasis and are possibly associated with testicular microlithiasis. Am J Hum Genet 2006;79:650-6.
7Jönsson ÅL, Simonsen U, Hilberg O, Bendstrup E. Pulmonary alveolar microlithiasis: Two case reports and review of the literature. Eur Respir Rev 2012;21:249-56.
8Barbolini G, Rossi G, Bisetti A. Pulmonary alveolar microlithiasis. N Engl J Med 2002;347:69-70.
9Gasparetto EL, Tazoniero P, Escuissato DL, Marchiori E, Frare E Silva RL, Sakamoto D. Pulmonary alveolar microlithiasis presenting with crazy-paving pattern on high resolution CT. Br J Radiol 2004;77:974-6.
10Hoshino H, Koba H, Inomata S, Kurokawa K, Morita Y, Yoshida K, et al. Pulmonary alveolar microlithiasis: High-resolution CT and MR findings. J Comput Assist Tomogr 1998;22:245-8.
11Helbich TH, Wojnarovsky C, Wunderbaldinger P, Heinz-Peer G, Eichler I, Herold CJ. Pulmonary alveolar microlithiasis in children: Radiographic and high-resolution CT findings. AJR Am J Roentgenol 1997;168:63-5.
12Wallis C, Whitehead B, Malone M, Dinwiddie R. Pulmonary alveolar microlithiasis in childhood: Diagnosis by transbronchial biopsy. Pediatr Pulmonol 1996;21:62-4.
13Marchiori E, Gonçalves CM, Escuissato DL, Teixeira KI, Rodrigues R, Barreto MM, et al. Pulmonary alveolar microlithiasis: High-resolution computed tomography findings in 10 patients. J Bras Pneumol 2007;33:552-7.
14Kang HW, Kim TO, Oh IJ, Kim YI, Lim SC, Choi YD, et al. A case of pulmonary alveolar microlithiasis. J Korean Med Sci 2011;26:1391-3.
15Sahoo MK, Karunanithi S, Bal CS. Pulmonary alveolar microlithiasis: Imaging characteristics of planar and SPECT/CT bone scan versus (18) F-FDG and (18) F-sodium fluoride PET/CT scanning. Jpn J Radiol 2013;31:766-9.
16Raffa H, El-Dakhaknny M, Al-Ibrahim K, Mansour MS. Single lung transplantation for alveolar micro-lithiasis: The first clinical report. Saudi J Kidney Dis Transpl 1996;7:189-93.
17Mascie-Taylor BH, Wardman AG, Madden CA, Page RL. A case of alveolar microlithiasis: Observation over 22 years and recovery of material by lavage. Thorax 1985;40:952-3.
18Palombini BC, da Silva Porto N, Wallau CU, Camargo JJ. Bronchopulmonary lavage in alveolar microlithiasis. Chest 1981;80:242-3.
19Chalmers AG, Wyatt J, Robinson PJ. Computed tomographic and pathological findings in pulmonary alveolar microlithiasis. Br J Radiol 1986;59:408-11.
20Pracyk JB, Simonson SG, Young SL, Ghio AJ, Roggli VL, Piantadosi CA. Composition of lung lavage in pulmonary alveolar microlithiasis. Respiration 1996;63:254-60.