A crucial complication after allogeneic hematopoietic cell transplantation (alloHCT), namely, acute graft-versus-host disease (aGVHD), occurs in about 50% of transplant recipients, leading to high morbidity and mortality. Thus far, the diagnosis of GVHD has been mainly established through clinical features and histologic or laboratory evidence of periductal lymphocyte infiltration, fibroplasia, and mixed lymphocytic and plasmocytic inflammation. Intensive research is focused on identifying biomarkers for the early diagnosis, prediction of disease, response to treatment, prognosis, and risk stratification of patients. The serum biomolecules that have been investigated are reported and summarized. Moreover, oral tissue involvement in GVHD is described, and other biomarkers that have been proposed, such as saliva, are analyzed. Future research is highlighted as a necessity in order for these biomarkers to be validated and quantified for use in clinical practice.

Ganglioneuromas are a very rare benign neural tumor, commonly derived from the ganglia of the sympathetic system, and are composed of mature Schwann cells, ganglion cells, and nerve fibres. They may arise anywhere from the base of the skull to the pelvis along the paravertebral sympathetic plexus. We report a rare case of synchronous ganglioneuroma and schwannoma, mistaken for carotid body tumor. The coexistence of these two entities in head and neck region is very rare.

Chondroid syringoma, or pleomorphic adenoma of the skin, is a rare, benign skin adnexal tumor. It is usually exhibited as a slowly growing intradermal or subcutaneous nodule, typically located in the head and neck region. Because of the unremarkable clinical symptomatology of this rare tumor, the diagnosis is exclusively made retrospectively based on histological confirmation of the surgically excised tumor. We present a rare case of a chondroid syringoma located in the left medial canthus of a 58-year-old man. The patient had no symptoms and decided to excise it for cosmetic reasons only. Local excision with a macroscopic wide cuff of normal tissue was done, without destroying the aesthetic and functional structures, since the defect was restored by a finger flap. One year postoperatively, the patient has remained disease-free. Chondroid syringoma usually appears in the face but the location in the medial canthus is not mentioned in the literature for the last twenty years.