Lymphohistiocytoid malignant mesothelioma

Definition

This is a rare subtype, constituting less than 1% of all of malignant mesotheliomas3. It has traditionally been classified with sarcomatoid mesothelioma, but its prognosis is more in keeping with the usual epithelioid mesothelioma.

Epidemiology

Patients are usually elderly, with a mean of 70 years1. As for other mesotheliomas, men are more often afflicted than women. There is an association with prior asbestos exposure.

Clinical features

Presentation may be with chest pain, weight loss or fatigue.

Macroscopic appearances

There may be diffuse pleural thickening, pleural nodularity and a pleural effusion, lymphocytic or haemorrhagic.

Histopathology

There is a diffuse proliferation of large non-cohesive cells with eosinophilic cytoplasm, vesicular nuclei and prominent nucleoli, resembling histiocytes. Some may resemble Reed-Sternberg cells. There may be a malignant spindle cell component3. In one case, the atypical cells resembled ganglion cells3. In some cases, there is an infiltrate of plasma cells or eosinophils.

Immunohistochemistry

 

 

Histiocytoid cells

Lymphoid cells

 
 

AE1/AE3

100%1, 3/44, 3/33

 

 

Calretinin

100%1, 3/44, 2/33

 

CK 5/6

46%1

 

HBME1

1/33

 

Thrombomodulin

1/33

 

EMA

52%1

 

CEA

0/41, 0/33

 

BerEP4

0/33

 

B72.3

0/41, 0/33

 

BG-8

0/33

 

Vimentin

2/33

 

CD15

0/41, 1/33

 

CD30

0%1

 

CD45

0%1, 0/33

 

CD68

0/3

4/44

S100

0%1

 

CD3

0/33

positive1, 4/41, 3/33

CD4

 

very few cells1

CD5

0/33

3/33

CD8

 

positive1, 4/41

CD20

0/33

scattered cells3

CD43

0/33

3/33

TDT

0/33 

negative1, 0/33

LMP

 

negative1

EBER-1

 

negative1

     

Ultrastructure

Scattered cells have sinuous villi, intracytoplasmic lumina lined by microvilli and tonofilament bundles2,4.

Differential diagnosis

Management

Patients have been managed by pleurodesis, chemotherapy and radiotherapy.

Prognosis

The median survival is 32 to 40 months1.

References

1 Galateau-Salle F, Attanoos R, Gibbs AR, et al. Lymphohistiocytoid variant of malignant mesothelioma of the pleura: a series of 22 cases. Am J Surg Pathol 2007; 31:711-6

2 Henderson DW, Attwood HD, Constance TJ, et al. Lymphohistiocytoid mesothelioma: a rare lymphomatoid variant of predominantly sarcomatoid mesothelioma. Ultrastruct Pathol 1988; 12:367-84

3 Khalidi HS, Medeiros LJ,Battifora H. Lymphohistiocytoid mesothelioma. An often misdiagnosed variant of sarcomatoid malignant mesothelioma. Am J Clin Pathol 2000; 113:649-54

4 Yao DX, Shia J, Erlandson RA, et al. Lymphohistiocytoid mesothelioma: a clinical, immunohistochemical and ultrastructural study of four cases and literature review. Ultrastruct Pathol 2004; 28:213-28

 

This page last revised 31.5.2007.

©SMUHT/PW Bishop