Early Post-transplant Smooth Muscle Neoplasia of the Colon Presenting as Diminutive Polyps: A Case Complicating Post-transplant Lymphoproliferative Disorder

Abstract

A 44-year-old woman, 3 years post-transplant for pulmonary sarcoidosis, developed abdominal pain and diarrhea 13 months subsequent to an eradicated diffuse large B-cell-type, post-transplant lymphoproliferative disorder (PTLD) of the cecal region. Endoscopic examination identified multiple pale tan 5-to-9 mm rubbery nodules of the transverse and right colon in an otherwise unremarkable mucosa. Histology was characterized by bland smooth muscle proliferations, focally pushing into the mucosa. Immunohistochemistry (IHC), in situ hybridization (ISH), and polymerase chain reaction (PCR) of the sampled nodules confirmed Epstein-Barr virus (EBV) infection of neoplastic cells. To our knowledge, this is the first reported case of EBV-related post-transplant lymphoproliferative and smooth muscle neoplasms (PTSN) having distinct tropism for the colon. Endoscopic features of early PTSN, which in this case presented as diminutive polypoid lesions, have not been described previously.

Molecular and Clinicopathological Analysis of Epstein-Barr Virus–Associated Posttransplant Smooth Muscle Tumors

“…Monomorphic or polymorphic PTLD preceded PTSMT manifestation in 18% of patients (4,5,28,29,33,37,40,41). As could be expected from the known risk profiles of PTLD (1), most of these patients were children and the PTLD manifested significantly earlier than the PTSMT.…”

“…Polymorphic or monomorphic high grade B-cell PTLD manifestation occurred in a subgroup of patients with PTSMT (n = 12/68, 18%) (4,5,28,29,33,37,40,41). Except for one adult case (37), all of these patients were children (n = 11/12, 92%).…”

“…Except for one adult case (37), all of these patients were children (n = 11/12, 92%). All PTLD preceded PTSMT manifestation: PTLD occurred after a median of 14 months and PTSMT after a median of 38 months (p = 0.0108; Supplementary Figure S1).…”

“…Including our own five patients and data from 40 other case reports (2)(3)(4)(5)(7)(8)(9)(10)(11)(12)14,(17)(18)(19)(21)(22)(23)(26)(27)(28)(29)31,(34)(35)(36)(37)(38)40), we could analyze the morphological details. More than 50% of PTSMT were smaller than 5 cm (median diameter of unifocal tumor or the largest multifocal tumor 4 cm, range 0.8-15 cm).…”

“…Surgical approaches (n = 30/45, 67%) (2)(3)(4)6,7,10,13,14,19,21,26,28,(30)(31)(32)(33)35,37,38) included surgical resection alone or in combination with chemotherapy and/or reduced immunosuppression. Complete and incomplete resection of one or a few tumors in multi-PTSMT manifestation (e.g.…”