**2. Epidemiology**

It is usual in the literature to estimate between 3 and 5% the risk of a cardiac-transplanted patient developing a PTLD [1]; however, these figures are old and vary depending on immunosuppression and duration of patients' lives, fortunately improved in the last 10 years. The largest study on the epidemiology of PTLD [2] involved 175,732 organ transplants between 1987 and 2008, including 10% of heart transplants. Pulmonary cancers represent the most frequent cancers (386/100,000/years) just in front of the NHL (283/100,000/years) but the standardized incidence ratio (SIR) of the NHL is very clearly superior to that of all the other cancers. **Table 1** presents the incidence and the SIR of the main cancers according to the transplanted organ. The risk of PTLD persists as long as immunosuppression is used, that is, until death for cardiac transplant patients; it is maximum the first year after transplantation, with an SIR greater than 10, but remains stable thereafter, with a SIR between 3 and 10 for a follow-up of up to 15 years.

• The cerebral PTLDs are almost always monomorphic B lesions.

considered PTLDs even when they occur after transplantation.

**Early lesions Plasmacytic hyperplasia PTLD**

Monomorphic B PTLD Diffuse large B cell lymphoma

Monomorphic T PTLD T-cell lymphoma, non-otherwise specified

**3.2. Diagnosis and extension assessment**

Florid follicular hyperplasia PTLD

Classical Hodgkin lymphoma PTLD

**Table 2.** WHO classification for PTLD.

**Figure 1.** Gut necrosis due to a PTLD.

Polymorphic PTLD

• B-type diffuse B-cell monomorphic lesions are by far the most common PTLD.

• Follicular lymphomas, marginal zone lymphomas, and mantle cell lymphomas are not

**Infectious mononucleosis PTLD**

Post-Heart Transplantation Lymphoproliferations http://dx.doi.org/10.5772/intechopen.76042 185

Hepatosplenic T-cell lymphoma

Burkitt lymphoma Plasmacytoma-like

T/NK lymphoma

The presentation of PTLDs is not unambiguous and the signs are not specific. In early forms, an alteration of the general status with fever is often present. In the other forms, the clinical signs depend on the tumoral localizations; for this reason, the digestive localizations are frequent and can be a source of digestive disorders, pain, even perforation, or necrosis (**Figure 1**).


**Table 1.** Incidence and SIR of the main cancers developed after transplantation depending on the transplanted organ.

EBV, initially described as always associated with PTLDs, is actually only half of the time. Almost always found in children, most often on the occasion of a primary infection, and in early forms (before the first year after transplantation), it has become rare in the late forms, the most common situation of our days [3]. In cerebral PTLDs, representing 10% of PTLDs, EBV is almost always found [4].
