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Cystic pleomorphic adenoma of the lacrimal gland: a clinicopathologic study

Published:November 17, 2016DOI:https://doi.org/10.1016/j.jcjo.2016.08.005
      Pleomorphic adenoma is the most common benign epithelial tumour of the lacrimal gland. It is composed of both epithelial and mesenchymal elements; the latter mainly consists of myxoid stroma. Typically, on imaging, it presents as a well-defined, solid mass in lacrimal gland fossa with bony remodeling. Internal architecture of the tumour may be heterogeneous as the myxoid stroma within the tumour can be seen as hypodense areas. Presence of cystic spaces within pleomorphic adenoma of the lacrimal gland is extremely rare and can lead to misdiagnosis. Understanding the clinical and imaging features of lacrimal gland tumour is crucial in proper management and prognostication of a case. We report the clinical, imaging, and histopathologic features of 6 cases of predominantly cystic pleomorphic adenoma of the lacrimal gland. To the best of our knowledge, there are no reports highlighting the cystic nature of pleomorphic adenoma of the lacrimal gland.
      This was a retrospective study of patients with pleomorphic adenoma showing predominantly cystic spaces on imaging. The clinical details, radiographic and operative findings, and histopathology of these patients were reviewed. Cystic pleomorphic adenoma was defined where cystic component was more than solid component on imaging.
      A total of 6 cases were studied. The median age of the patients was 39 years (range: 16–56 years). Four patients were males. The duration of symptoms ranged from 1 to 4 years (median: 24 months). The right eye was involved in 3 cases. Painless proptosis with inferomedial globe dystopia was present in all cases (Fig. 1A). Restriction of extraocular movement was present in 5 cases, ptosis in 2 cases, and diplopia and decreased vision in 1 case. All masses were palpable; 4 were firm, whereas 2 were soft in consistency.
      Fig. 1
      Fig. 1(A) Clinical photograph shows mass in the right lacrimal gland region associated with inferomedial globe dystopia. (B) Computed tomography scan (axial section) shows right lacrimal gland mass with anterior solid component with calcification and posterior large cyst.
      Computed tomography scan in all 6 cases revealed a well-defined mass in the lacrimal gland region with bony remodeling and variable degrees of cystic spaces. An anterior solid mass with a large posterior cyst was seen in 1 case (Fig. 1B), whereas multicystic mass was seen in 5 cases (Fig. 2A, B). Surgical removal of the mass was done via lateral orbitotomy approach in 4 cases and anterior orbitotomy approach in 2 cases. In toto removal of the tumour was achieved in all cases except one, which was associated with inadvertent rupture of a cystic portion.
      Fig. 2
      Fig. 2(A) Computed tomography (CT) scan (coronal section) shows a large heterogeneous mass in the left lacrimal gland fossa with multiple cysts within the mass. Globe indentation is also present. (B) CT scan (sagittal section) shows a well-defined, heterogeneously enhancing multicystic mass associated with bony remodeling.
      Microscopic examination of all specimens was consistent with pleomorphic adenoma of the lacrimal gland. Cystic degeneration was present in all cases (Fig. 3A). Four cases showed predominantly hyaline stroma and 2 cases showed cellular predominance (Fig. 3B). Squamous metaplasia and focal nuclear atypia was noted in 1 case. None of the patients had recurrence at 1–6 years of follow-up.
      Fig. 3
      Fig. 3(A) Photomicrograph shows a cyst (arrow) lined with squamous epithelial cells, within the stromal (left) and cellular components (right) of pleomorphic adenoma of the lacrimal gland (H&E, 100×). (B) Photomicrograph shows pleomorphic adenoma of the lacrimal gland with cellular predominance with areas of cystic degeneration (hematoxylin and eosin, 100×). Cut section showing large cystic cavity (inset).
      Long-standing benign tumours can undergo cystic degeneration, necrosis, or haemorrhage leading to cavities within the tumour, which changes the characteristic imaging appearance. Tumours of the lacrimal gland bear a distinct resemblance to those found in the salivary glands or other secretory glands, irrespective of their site and function. Pleomorphic adenomas with cystic changes have been reported in major and minor salivary glands.
      • Nishimura T.
      • Furukawa M.
      • Kawahara E.
      Pleomorphic adenoma of parotid gland with cystic degeneration.
      • Takeshita T.
      • Tanaka H.
      • Harasawa A.
      • Kaminaga T.
      • Imamura T.
      • Furui S.
      Benign pleomorphic adenoma with extensive cystic degeneration: unusual MR findings in two cases.
      • Sudheendra S.U.
      • Shashidara R.
      • Chakki A.B.
      • Sreeshyla H.S.
      Cystic pleomorphic adenoma of minor salivary glands.
      In reported cases of cystic pleomorphic adenomas of the salivary gland, the masses were completely or predominantly cystic with small portion of solid component, unlike in our series, where multiple cysts within the solid mass were seen in most cases. In our case, the cyst was lined with a single layer of squamous epithelium (Fig. 3A). Thus, the possible origin of the cyst may be attributable to the squamous metaplasia of the tumour cells and secretions from these cells, which may lead to enlargement of the duct-like structures within the tumour. The areas of intratumoural haemorrhage or necrosis may also lead to cystic appearance on imaging.
      In 2 previous reports on lacrimal gland tumours from our centre, cystic changes were found in 4% cases (2 out of 50 cases) on imaging and cystic degeneration in 36% and 16% cases on histopathology, respectively.
      • Chawla B.
      • Kashyap S.
      • Sen S.
      • et al.
      Clinicopathologic review of epithelial tumors of the lacrimal gland.
      • Sen S.
      • Mahindrakar A.
      • Betharia S.M.
      Pleomorphic adenomas of the lacrimal gland: a clinicopathological analysis.
      Preoperative differentials in cystic pleomorphic adenomas of salivary gland usually are lymphoepitheloid cyst, mucocele, and pseudocysts from a neoplastic lesions such as Warthin’s tumour and adenocarcinoma. According to the incidence of lacrimal gland tumours, the possible differentials in cases with multicystic appearance are pseudocysts within a tumour-like adenoid cystic carcinoma, adenocarcinoma, carcinoma ex pleomorphic adenoma, and rarely benign lesions such as dacryops or cystadenoma.
      • Chawla B.
      • Kashyap S.
      • Sen S.
      • et al.
      Clinicopathologic review of epithelial tumors of the lacrimal gland.
      • Bajaj M.S.
      • Pushker N.
      • Kashyap S.
      • Balasubramanya R.
      Cystadenoma of the lacrimal gland.
      Cystic appearance on imaging poses a diagnostic and therapeutic challenge. In toto excision along with pseudocapsule is advised for the treatment of pleomorphic adenoma, but in such a scenario, dissection becomes difficult along the cystic wall, leading to risk of rupture and spillage of the contents. We emphasize that the diagnosis of pleomorphic adenoma should be kept in differentials of well-defined cystic masses in lacrimal fossa. Preoperative diagnosis can help in careful and complete surgical removal of the tumour by the lateral orbitotomy approach, which provides more working space than an anterior approach and hence avoids rupture and prevents recurrence of tumour.

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