Indian Journal of Pathology and Microbiology

: 2020  |  Volume : 63  |  Issue : 4  |  Page : 658--660

Pulmonary hyalinizing granuloma – An uncommon malignant masquerade

Tharageswari Srinivasan1, Saravana Rajamanickam2,  
1 Department of Pathology, SPMM Hospital, Salem, Tamil Nadu, India
2 Department of Surgical Oncology, SPMM Hospital, Salem, Tamil Nadu, India

Correspondence Address:
Tharageswari Srinivasan
Department of Pathology, 29, Cuddalore Main Road, Ammapet, Salem - 636 003, Tamil Nadu

How to cite this article:
Srinivasan T, Rajamanickam S. Pulmonary hyalinizing granuloma – An uncommon malignant masquerade.Indian J Pathol Microbiol 2020;63:658-660

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Srinivasan T, Rajamanickam S. Pulmonary hyalinizing granuloma – An uncommon malignant masquerade. Indian J Pathol Microbiol [serial online] 2020 [cited 2022 Jun 30 ];63:658-660
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Full Text

Pulmonary hyalinizing granuloma (PHG) is a rare benign lung lesion that presents as solitary or multiple lung nodules, simulating a malignant disease by clinical and imaging studies.[1] Up to 25% of the patients are asymptomatic at the time of the presentation.[1] Rest of the patients present with vague chest symptoms such as cough, breathlessness, hemoptysis, and so on. Etiology is unknown, the postulated mechanism is an exaggerated immune response to antigenic stimuli.[2] Clinical and imaging studies cannot differentiate this benign condition from malignant disease, therefore, histopathological examination is needed for correct diagnosis. We report a case of PHG presented as a solitary lung nodule mimicking a malignant lung tumor by imaging studies.

A 55-year-old farmer, active smoker with a 30-pack year smoking history presented with a history of cough for 3 months with gradual loss of weight and appetite. The patient complained of fever on and off for 2 weeks. Chest X-ray showed a large opacity in the right lower and middle zone of the lung. Computed tomography (CT) thorax showed 11 cm × 9 cm non-cavitating mass lesion in the hilar aspect of the right middle lobe. The mass showed peripheral spiculation, loss of tissue planes with mediastinum, and crossing on to the lower lobe along the major fissure [Figure 1]. Multiple nodes were present along the interlobar pulmonary artery. CT-guided biopsy of the lesion was suspicious of spindle cell lesions. Immunohistochemistry (IHC) was, however, noncontributory. Endobronchial ultrasound (EBUS) transbronchial needle aspiration (TBNA) of the mediastinal lymph nodes were negative for malignancy.{Figure 1}

On thoracotomy, an 8 cm × 6 cm hard tumor was seen involving the middle and lower lung lobes. A lower bilobectomy was performed as the lesion was infiltrating the anterior aspect of the major fissure.

On gross examination, a circumscribed unencapsulated lesion measuring 6 cm × 6 cm × 4 cm was seen in the middle lobe [Figure 2]. The lesion had firm gray-white areas with focal gray-tan spots. No evidence of necrosis or hemorrhage was seen. Microscopy showed central hypocellular areas with thick ropy collagenous eosinophilic deposits arranged in nodular, parallel lamellated, and storiform patterns [Figure 3]. The periphery of the lesion shows cellular areas with lymphocytes, plasma cells, and a few giant cells. Masson's Trichrome stain confirmed the eosinophilic material to be collagen [Figure 4].{Figure 2}{Figure 3}{Figure 4}

The patient had an uneventful postoperative recovery and was discharged on postoperative day 6. The patient underwent reoperation for “trapped” lung 2 months after the primary procedure. There was, however, no evidence of recurrence. The patient has been followed up for 28 months now; he is alive and remains disease-free.

PHG is a rare benign lung lesion first described by Eugelmann et al. in 1977. It equally affects both the sexes, usually presenting in the fourth and fifth decades of life. The patients may be asymptomatic or present with vague chest complaints of cough, chest pain, dyspnea, hemoptysis, and so on.[1] It usually presents as multiple nodules in the lung thus mimicking cancer. Rarely, it may present as a solitary nodule simulating a primary lung malignancy. TFNAB, endobronchial biopsies, or bronchoalveolar lavages are usually not efficient for diagnosis.[3] Histopathological examination of the adequate sample obtained by open lung biopsy is required for diagnosis.[4] Histological findings are rather specific with extracellular eosinophilic collagen bundles arranged haphazardly or in concentric lamellar patterns.[3] Plasma cells, lymphocytes, and a few giant cells seen interspersed between the lamellated collagen bundles. In the early active lesion, cellular components predominate, while the collagen lamellar bands predominant in the older chronic lesion.[4]

The etiology of PHG is unknown. The proposed mechanism is an exaggerated immune response to antigenic stimuli associated with various infective or immune-mediated conditions. Cases have been reported to be associated with sclerosing mediastinitis, retroperitoneal fibrosis, rheumatoid arthritis, posterior uveitis, or lymphoproliferative conditions such as multiple myeloma, B cell lymphomas, and so on.

Prognosis is usually excellent in cases of solitary lesions. Multiple lesions have a comparatively worse prognosis as these multiple lesions might enlarge and coalesce causing impaired pulmonary function over time. Prognosis is significantly worse when it is associated with sclerosing mediastinitis or retroperitoneal fibrosis that can develop in the course of the disease.[5]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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1Coleman C, Nassar A, McComb B. Pulmonary hyalinizing granuloma associated with idiopathic thrombocytopenic purpura. J Clin Imaging Sci 2014;4:8.
2Uzer F, Ozbudak IH, Ozbudak O, Cilli A. Pulmonary hyalinizing granuloma in the differential diagnosis of pulmonary carcinoma. Clin Med Rev Case Rep 2018;5:209.
3Düzgün N, Kurtipek E, Esme H, ErenKaranis Mİ, Tolu İ. Pulmonary hyalinizing granuloma mimicking metastatic lung cancer. Case Rep Pulmonol 2015;2015:610417. doi: 10.1155/2015/610417.
4Esme H, Ermis SS, Fidan F, Unlu M, Dilek FH. A case of pulmonary hyalinizing granuloma associated with posterior uveitis. Tohoku J Exp Med 2004;204:93-7.
5Chapman EM, Gown A, Mazziotta R, Churg A. Pulmonary hyalinizing granuloma with associated elevation in serum and tissue IgG4 occurring in a patient with a history of sarcoidosis. Am J Surg Pathol 2012;36:774-8.