Trichodysplasia spinulosa (TS) is a rare and only recently characterized cutaneous disease occurring in immunocompromised patients. The disease is characterized by spiny follicular papules on clinical examination and by the presence of viral inclusions at ultrastructural examination. In the last year, this virus has been identified as a new member of the polyomavirus family and designated as TS-associated polyomavirus (TSPyV). We report two organ transplant patients with this disease in which we were able to identify the TSPyV at ultrastructural and molecular level from formalin-fixed paraffin-embedded biopsies of lesional skin. Similar to prior described cases, the patients presented with follicular papules which were concentrated on the central face and associated with alopecia. Histopathology of both cases showed dilated follicular infundibula plugged with cornified eosinophilic cells containing large trichohyaline granules. Transmission electron microscopy on paraffin-embedded tissue in case 1 showed 28-nm intracellular viral particles morphologically consistent with polyoma virus. For both cases the presence of TSPyV was confirmed by polymerase chain reaction with virus-specific primers followed by identification by direct sequencing. These two cases show the presence of the newly described TSPyV in TS further establishing its association with this distinctive disease.

Molecular diagnostic strategies are gaining wider acceptance and use in dermatology and dermatopathology as more practitioners in this field develop an understanding of the principles and applications of genomic technologies. Molecular testing is facilitating more accurate diagnosis, staging, and prognostication, in addition to guiding the selection of appropriate treatment, monitoring of therapy, and identification of novel therapeutic targets, for a wide variety of skin diseases.

Primary cutaneous amyloidosis describes a group of disorders in which amyloid is deposited in the skin without evidence of systemic involvement. Nodular localized primary cutaneous amyloidosis (NLPCA) is a rare form of these skin-restricted amyloidoses. We present an unusual case of NLPCA in a 51-year-old man, who had clinical and histopathological evidence of subepidermal bullous formation, a unique feature in NLPCA. The possible pathogenesis of this change is discussed.

Acute graft-versus-host disease (aGvHD) is a rare complication of liver transplantation associated with high morbidity and mortality. Death typically occurs due to complications related to severe infection, shock, and multiorgan failure. The clinical presentation involves dysfunction of multiple organ systems with overlapping symptoms that often results in a diagnostic delay. As there are a limited number of cases reported in the literature, there are no clear guidelines for treatment. Many different therapeutic measures have been utilized that target various immune system pathways, but steroids remain the first line of therapy. We report on two patients who developed aGvHD after liver transplantation who were treated with ruxolitinib, a novel Janus kinase 1/2 (JAK) inhibitor that has been shown to improve outcomes in steroid refractory cases of aGvHD after allogenic hematopoietic stem cell transplantation. We reviewed the literature to discuss various therapeutic options currently available for aGvHD after liver transplantation.