Micronodular thymoma with lymphoid stroma: Two cases, one in a multilocular thymic cyst, and literature review

Micronodular thymoma with lymphoid stroma (MTWLS) is a rare type of thymoma that shows a similar pattern but varied morphology and immunophenotype of tumor cells. Because of the extremely limited number of cases reported, the pathology and biology of MTWLS are equivocal. Herein, we report two cases located in the anterior mediastinum: Case 1: a 58‐year‐old woman with a cystic mass measuring 5 × 3.0 × 2.5 cm in Mosaoka stage I; and Case 2: a 50‐year‐old man with a solid mass measuring 2.5 × 2.5 × 2.0 cm in stage IIb. Both patients were treated by thymectomy and are alive without recurrence or metastasis 15 and 17 months after surgery, respectively. Regardless of the spectrum of pathology and stage of MTWLS, this unique type of thymoma has a homogeneously favorable prognosis.

[1]  S. Badve,et al.  Micronodular thymic neoplasms: case series and literature review with emphasis on the spectrum of differentiation , 2015, Modern Pathology.

[2]  A. Nicholson,et al.  Introduction to The 2015 World Health Organization Classification of Tumors of the Lung, Pleura, Thymus, and Heart. , 2015, Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer.

[3]  A. Nicholson,et al.  The Impact of Thymoma Histotype on Prognosis in a Worldwide Database , 2015, Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer.

[4]  S. Ha,et al.  Micronodular Thymoma with Lymphoid Stroma in a Multilocular Thymic Cyst: A Case Study , 2013, Korean journal of pathology.

[5]  K. Kawaguchi,et al.  Multilocular Thymic Cyst Associated With Thymoma: A Clinicopathologic Study of 20 Cases With an Emphasis on the Pathogenesis of Cyst Formation , 2012, The American journal of surgical pathology.

[6]  N. Khandelwal,et al.  Thymic carcinoma developing in a multilocular thymic cyst. , 2012, Journal of thoracic disease.

[7]  C. Moran,et al.  Micronodular thymic carcinoma with lymphoid hyperplasia: a clinicopathological and immunohistochemical study of five cases , 2012, Modern Pathology.

[8]  C. Moran,et al.  Thymic Carcinoma Associated With Multilocular Thymic Cyst: A Clinicopathologic Study of 7 Cases , 2011, The American journal of surgical pathology.

[9]  G. Giaccone,et al.  A population‐based assessment of mortality and morbidity patterns among patients with thymoma , 2011, International journal of cancer.

[10]  Scott Martin Bailey,et al.  On the spectrum , 2010 .

[11]  O. Ismail,et al.  Micronodular thymoma with lymphoid stroma: report of two cases and particular association with thymic lymphoid hyperplasia in one case. , 2006, Pathology.

[12]  H. Müller-Hermelink,et al.  Micronodular thymoma: an epithelial tumour with abnormal chemokine expression setting the stage for lymphoma development , 2005, The Journal of pathology.

[13]  Kazuhisa Takahashi,et al.  Multilocular thymic cyst associated with follicular hyperplasia: clinicopathologic study of 4 resected cases. , 2005, Human pathology.

[14]  J. Fléjou,et al.  Cervical ectopic thymoma: a diagnostic pitfall on frozen section , 2005, Histopathology.

[15]  A. Marx,et al.  Ectopic micronodular thymoma with lymphoid stroma , 2004, Virchows Archiv.

[16]  V. Thomas de Montpréville,et al.  [Thymoma with epithelial micronodules and lymphoid hyperplasia: six cases of a rare and equivocal subtype]. , 2002, Annales de pathologie.

[17]  M. Okumura,et al.  The spectrum of micronodular thymic epithelial tumours with lymphoid B‐cell hyperplasia , 2001, Histopathology.

[18]  S. Suster,et al.  Micronodular thymoma with lymphoid B-cell hyperplasia: clinicopathologic and immunohistochemical study of eighteen cases of a distinctive morphologic variant of thymic epithelial neoplasm. , 1999, The American journal of surgical pathology.