When two or more cutaneous tumours coexist in a single lesion, it is known as a cutaneous collision or contiguous tumour. Various combinations of collisions have been described. Collision tumours often have misleading clinical and histological presentations, and can be a diagnostic challenge. Chondroid syringomas are mixed cutaneous tumours of dual origin, and like collision tumours, are often confused with the more commonly seen cutaneous lesions. As chondroid syringomas are rare, their involvement in collision tumours is an even more peculiar occurrence. We report an unusual case of a cutaneous collision tumour on the nose involving an intradermal naevus and chondroid syringoma. To the best of our knowledge, this is the first time such a combination is reported.
Aged ; Carcinoma, Basal Cell ; diagnosis ; Diagnosis, Differential ; Female ; Humans ; Keratosis, Seborrheic ; pathology ; Neoplasms, Multiple Primary ; pathology ; Nevus, Pigmented ; pathology ; Nose Neoplasms ; diagnosis ; Skin Neoplasms ; pathology

Cutaneous pseudolymphoma is an uncommon, benign lymphoproliferative disorder of the skin. Although this condition is most commonly idiopathic, its occurrence has been associated with cosmetic tattoos. We report a unique case of cutaneous pseudolymphoma that occured after accidental, traumatic inoculation of a red pigment in a healthy 33-year-old woman.
Adult ; Betamethasone ; analogs & derivatives ; therapeutic use ; Biopsy ; Coloring Agents ; adverse effects ; Female ; Forehead ; pathology ; Humans ; Lacerations ; Lymphoproliferative Disorders ; diagnosis ; etiology ; Pseudolymphoma ; chemically induced ; diagnosis ; Skin ; pathology ; Skin Diseases ; chemically induced ; diagnosis ; Triamcinolone Acetonide ; therapeutic use

Facial Dermatoses ; diagnosis ; pathology ; Humans ; Male ; Pyoderma Gangrenosum ; diagnosis ; pathology ; Sweet Syndrome ; diagnosis ; pathology ; Young Adult

INTRODUCTIONGenetic predisposition to clear cell renal cell carcinoma (ccRCC) has been linked to disorders such as von Hippel-Lindau (VHL) syndrome. While twin research is a classic approach for elucidating genetic and environmental contributions to disease, no monozygotic twin-pair concordant for ccRCC in the absence of VHL syndrome has been previously reported in the literature or in major twin registries.

CLINICAL PICTUREWe describe a unique monozygotic twin-pair concordant for ccRCC, with discordant but early ages of onset of 25 and 38 respectively. Cytogenetic studies and direct sequencing for VHL gene mutations in the second twin proved unremarkable.

CONCLUSIONSThis is the fi rst reported case of monozygotic twins concordant for ccRCC in the absence of VHL gene mutation. The early yet discordant, age of onset of disease in both twins suggests both genetic and environmental contributions to ccRCC.

Adult ; Carcinoma, Renal Cell ; genetics ; pathology ; Diseases in Twins ; genetics ; pathology ; Humans ; Kidney Neoplasms ; genetics ; pathology ; Male ; Twins, Monozygotic ; von Hippel-Lindau Disease ; genetics