Thymic Mass

Etiology

WHO histologic typing of tumors of the thymus
1. Epithelial tumors

1.1 Thymoma
1.1.1 Type A (spindle cell; medullary)
1.1.2 Type AB (mixed)
1.1.3 Type B1 (lymphocyte-rich; lymphocytic; predominantly cortical; organoid)
1.1.4 Type B2 (cortical)
1.1.5 Type B3 (epithelial; atypical; squamoid; well-differentiated thymic carcinoma)

1.2 Thymic carcinoma (type C thymoma)
1.2.1 Epidermoid keratinizing (squamous cell) carcinoma
1.2.2 Epidermoid non-keratinizing carcinoma
1.2.3 Lymphoepithelioma-like carcinoma
1.2.4 Sarcomatoid carcinoma (carcinosarcoma)
1.2.5 Clear cell carcinoma
1.2.6 Basaloid carcinoma
1.2.7 Mucoepidermoid carcinoma
1.2.8 Papillary carcinoma
1.2.9 Undifferentiated carcinoma

  1. Neuroendocrine tumors

2.1 Carcinoid tumor (well-differentiated neuroendocrine carcinoma)
2.1.1 Classic
2.1.2 Spindle cell
2.1.3 Pigmented
2.1.4 With amyloid (extrathyroid medullary carcinoma)
2.1.5 Atypical
2.2 Small cell carcinoma (poorly differentiated neuroendocrine carcinoma)
2.2.1 Mixed small cell-epidermoid keratinizing carcinoma
2.3 Large cell neuroendocrine carcinoma

  1. Germ cell tumors

3.1 Seminoma (germinoma)
3.2 Embryonal carcinoma
3.3 Yolk sac tumour
3.4 Choriocarcinoma
3.5 Teratoma
3.5.1 Mature teratoma
3.5.2 Immature teratoma
3.5.3 With sarcoma
3.6 Mixed germ cell tumour

  1. Lymphoid tumors

4.1 Hodgkin’s lymphoma
4.1.1 Nodular sclerosis
4.2 Large cell lymphoma
4.2.1 With sclerosis
4.3 Lymphoblastic lymphoma
4.4 Anaplastic large cell lymphoma
4.5 MALT-type lymphoma

  1. Stromal tumors

5.1 Thymolipoma
5.2 Thymoliposarcoma
5.3 Solitary fibrous tumour
5.4 Rhabdoid tumour

  1. Tumor-like lesions

6.1 True thymic hyperplasia
6.2 Lymphoid hyperplasia (lymphofollicular thymitis)
6.3 Multilocular thymic cyst
6.4 Langerhans Cell Histiocytosis (LCH) (see Langerhans Cell Histiocytosis, [[Langerhans Cell Histiocytosis]])

  1. Neck tumors of thymic or related branchial pouch derivation

7.1 Ectopic hamartomatous thymoma
7.2 Ectopic cervical thymoma
7.3 Spindle epithelial tumour with thymus-like differentiation (SETTLE)
7.4 Carcinoma showing thymus-like differentiation (CASTLE)

  1. Metastatic tumours

  2. Unclassified tumours


Clinical Manifestations


References

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