Israel Medical Association Journal

Background: Solid organ transplant recipients (SOTRs) are at increased risk for both skin and internal malignancies (IM). The risk of IM after the occurrence of non-melanoma skin cancer (NMSC) has been studied in the general population but very little is known about this association in SOTRs.

Objectives: To evaluate the risk of IM following a prior diagnosis of post transplantation NMSC in SOTRs.

Methods: This single center retrospective cohort study included a study population of 329 SOTRs from Rabin Medical Center who had a post-transplant diagnosis of skin malignancy, internal malignancy, or both from 2012 to 2018.

Results: In total, 135 (41.03%) SOTRs were diagnosed with IM without a preceding diagnosis of NMSC while only 42 (12.76%) patients diagnosed with IM had a preceding diagnosis of NMSC. SOTRs with a diagnosis of NMSC showed a significantly decreased risk of developing subsequent IM (hazard ratio [HR] 0.64, 95% confidence interval [95%CI] 0.44–0.94, P = 0.02) compared to those without a prior NMSC diagnosis. Liver and lung transplant patients showed a significantly decreased risk of developing subsequent IM after a diagnosis of NMSC (HR 0.09 and 0.43, respectively). When stratified by type of IM, only patients who were diagnosed with a hematological malignancy had a significantly lower risk of developing this malignancy if they had a prior NMSC (HR 0.26).

Conclusions: The findings of this study suggest a protective effect of NMSC on subsequent IM in the organ transplant population.

Background: Whole-body integrated positron emission tomography / contrast-enhanced computed tomography (PET/CT) scan is increasingly used in cutaneous lymphomas. However, the value of PET/CT in the detection of cutaneous lesions in primary cutaneous B-cell lymphoma (PCBCL) has barely been investigated.

Objectives: To investigate the diagnostic accuracy of PET/CT in tracking cutaneous involvement in PCBCL.

Methods: A retrospective study was conducted on 35 consecutive patients diagnosed with cutaneous B-cell lymphoma according to the World Health Organization classification who were evaluated with PET/CT as the initial staging procedure before treatment.

Results: Thirty-five patients met the study criteria. In two patients extracutaneous disease was detected by PET/CT and CT and confirmed by biopsy. Of the 33 patients with PCBCL, 26 (79%) had small cell PCBCL (18 marginal-zone, 8 follicle-center lymphoma) and 7 (21%) had large cell PCBCL (3 follicle-center, 3 leg-type, 1 indeterminate). PET/CT detected skin lesions in 3 of 26 patients (12%) with small-cell PCBCL as compared to 6 of 7 patients with large-cell PCBLC (86%), a 7.4-fold detection risk (95% confidence interval, 2.4–22, P = 0.004). The PET-positive subgroup was characterized by larger lesion size (P < 0.001) and a higher Ki-67 proliferation index (P < 0.001).

Conclusions: The sensitivity of PET/CT for detecting cutaneous involvement of lymphomas is low for small-cell PCBCL but high for large-cell types, and thus may facilitate therapeutic strategies.