Lymphoepithelial Cystic Lesion Related to Adenocarcinoma in the Mediastinum

Abstract

The authors report here a case of lymphoepithelial cystic lesion (LECL) of unknown origin in the mediastinum, which is closely related to a signet-ring cell adenocarcinoma. A 73-year-old man presented with a mass as revealed on a chest x-ray. During surgical operation, a solid, well-circumscribed and encapsulated 9 X 9 X 8 cm tumor was isolated from the right anterior mediastinum. This tumor had neither undergone metastasis nor invaded into the surrounding tissue and lymph nodes. Light microscopy revealed the tumor to be a signet-ring cell adenocarcinoma. Clinically, the neoplasm was coupled with an elevation in serum CEA level, which promptly returned to normal values following surgical removal. Immunohistochemistry pointed out that the majority of neoplastic cells stained positive for CEA. In addition, LECL of unknown origin was distinguished at the periphery of the tumor. LECL was characterized by microcysts which were lined by columnar epithelial and surrounded by lymphoid tissue with germinal centers. Transition between the neoplastic cells and benign epithelial cells of LECL was evident, showing that the previously mentioned mediastinal adenocarcinoma may be derived from the epithelial elements of LECL. This paper discusses the histogenesis of LECL.

Lymph node cancer of the mediastinum with a putative necrotic primary lesion in the lung: a case report

“…On the other hand, the lymph node itself may be the primary focus. In the latter case, malignant transformation of the ectopic epithelium in the lymph node may be responsible [ 10 , 13 – 15 ]. However, all of these mechanisms are hypothetical and not based on scientific evidence.…”

Lymphoepithelial Cysts in the Mediastinum with an Opening to the Trachea

“…To the best of our knowledge, a LEC of unknown origin located in the mediastinum has been reported only once: Ishimaru et al [3] described a 73-year-old man suffering from general fatigue who was found to have a solid mass in the anterior mediastinum on conventional chest roent genogram and CT scan. Like our case, the cyst's wall was surrounded by lymphoid tissue with germinal centers.…”

“…The lesion, however, was different from the current case in that it was occupied with signet-ring cell adenocarcino ma and was not connected to the trachea. Ishimaru et al [3] noted that the adenocarcinoma might have derived from the epithelial element of LEC lesion and speculated that it was either a thymic cyst derived from a remnant of the third branchial pouch or a branchial cyst derived from a remnant of the second branchial pouch that was mis placed in the anterior mediastinum.…”

“…A LEC in the mediastinum is extremely rare and its histogenesis is uncertain. The literature lists only 1 case where the lesion was in the anterior mediastinum containing an adenocarcinoma [3]. The case described had multiple LECs in the upper mediastinum, and one of which had an opening to the trachea.…”

A case report of anterior mediastinal signet ring cell carcinoma

“…[10] Anterior mediastinal SRCC is rare and the first related case of a lymphoepithelial cystic lesion (LECL) dates back to 1989. [11] Only 2 cases of primary thymic SRCC have been since been reported. [12] Here, we report on a unique case of the anterior mediastinal SRCC.…”