The neuropathological hallmark of the C9orf72 intronic hexanucleotide expansion in frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) is the presence of small ubiquitin/p62-positive and transactive response DNA binding protein 43 kDa (TDP-43)-negative cytoplasmic inclusions in several brain areas. The identification of this histopathological signature is highly predictive of an underlying mutation. In this study, we screened 1800 cases of the Barcelona IDIBAPS Brain Bank, independently of the clinical and final neuropathological diagnosis of the brain donor, for the presence of ubiquitin/p62-positive inclusions in the cerebellum (UPPI). Positive cases were also stained for dipeptide repeats. We identified a total of 21 donors with UPPI and in all of them the C9orf72 hexanucleotide expansion was genetically confirmed. Most donors had an FTLD or to a lesser extent ALS clinico-pathological phenotype. However, 3 cases had been previously classified as having clinically and neuropathologically Lewy body disease. Other co-existing pathologies, especially of the PART-type, were also frequently encountered. This study highlights the importance of the evaluation of ubiquitin/p62-positive cytoplasmic inclusions in all neurodegenerative diseases as a good screening method for the detection of C9orf72 expansion mutation, since this mutation is not rare and can overlap with other neurodegenerative entities.

We report a case of a 71 year old man who presents to our hospital with a non-painful enlargement of the right testicle and an indurated area over the testis. The patient has a working history of asbestos exposure. Scrotal sonography shows a right hydrocele and a heterogeneous mass at the right spermatic cord. Abdominal CT scan confirms the presence of a supratesticular oval mass of 14.5 × 4.7 cm which reaches the inguinal canal and seems to depend on the spermatic cord.The patient undergoes right orchyectomy. Histological examination shows an infiltrating malignant papillary spermatic cord mesothelioma.CT scan reveals signs of right pleural mesothelioma with ipsilateral pleural effusion, pleural implants, multiple lymphadenopathies and an anterior pneumothorax. A pleural biopsy reveals the presence of malignant epithelioid mesothelioma.The comparison of both neoplasms hints at a similarity in their immunohistochemical profile and morphology.The patient receives first line chemotherapy with six cycles of cisplatin/pemetrexed, having obtained a maintained partial response and an illness progression-free interval of 3 months. However, in the last CT scan, one-two interaortocaval lymph nodes are detected, which were not previously evidenced, so active surveillance is maintained.