Incidental lymphomas in surgical pathology: diagnostic clues and clinical-pathological correlations.

Incidental lymphomas (ILs) are rare and challenging lesions with poorly characterized clinical-epidemiological and histological features. The present study addressed the open issues concerning these tumors, by assessing the clinical-pathological features of 28 consecutive ILs, diagnosed over a 10-year period at a tertiary center for surgical pathology. ILs were more frequently documented in elderly males (mean age at surgery 70.8 years; M/F ratio 3.3), with sharp prevalence of gastrointestinal and urinary tract involvement (22/28 [78.6%] cases). Low-grade B-cell lymphomas outnumbered all other entities, and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) was the most common subtype (18/28 [64.3%] cases). Compared to other ILs, CLL/SLL occurred at older age and was the sole lymphoid neoplasm affecting the urinary tract. In conclusion, ILs are rare lesions, mostly affecting the gastrointestinal and urinary tract of elderly males. The diagnosis of IL is based on a high degree of suspicion and on careful morphological/phenotypic characterization.

Gastrointestinal lymphoproliferative lesions: a practical diagnostic approach.

The gastrointestinal tract (GI) is the primary site of lymphoproliferative lesions, spanning from reactive lymphoid hyperplasia to overt lymphoma. The diagnosis of these diseases is challenging and an integrated approach based on clinical, morphological, immunohistochemical and molecular data is needed. To reach to confident conclusions, a stepwise approach is highly recommended. Histological evaluation should first assess the benign versus neoplastic nature of a given lymphoid infiltrate. Morphological and phenotypic analyses should then be applied to get to a definite diagnosis.This review addresses the key histological features and diagnostic workup of the most common GI non-Hodgkin lymphomas (NHLs). Differential diagnoses and possible pitfalls are discussed by considering distinct groups of lesions (i.e. small to medium B-cell NHLs; medium to large B-cell NHLs; T-cell NHLs; and mimickers of Hodgkin lymphoma). The key clinical and epidemiological features of each entity are also described.

Two fatal intoxications by colchicine taken for saffron. Clinical, medico-legal and forensic toxicological implications.

Although fatal colchicine intoxications are rare and mostly related to suicidal intake or accidental overdose, other hypotheses should be considered when dealing with colchicine poisoning. We present a case of double, acute, and subacute, fatal colchicine intoxication in a married couple. The 70-year-old male victim suddenly died after vomiting and diarrhea. The next day his wife showed aggravating gastrointestinal symptoms and was hospitalized with a diagnosis of septic shock. A complete postmortem examination on the man was performed, together with histopathological analysis. Toxicological examination performed through liquid chromatography coupled to mass spectrometry revealed a colchicine blood peripheral concentration of 33 ng/mL. A few days after hospitalization, the woman showed a colchicine plasma concentration of 32 ng/mL. Despite veno-venous hemofiltration, she ultimately died of septic shock and multi-organ failure. Death scene investigation revealed that, a few days before the death of the male victim, the couple had collected wild saffron and had eaten a presumed saffron risotto. The integrated analysis of circumstantial, clinical, postmortem and toxicological data allowed to establish that the couple had died of a fatal accidental intoxication due to the ingestion of natural colchicine, mistaken for saffron. The death of the male was deemed caused by acute cardiovascular collapse induced by acute intoxication, while the female had suffered a subacute poisoning by antimitotic agent, resulting in immunosuppression and systemic infection. Toxicological analyses, promptly performed on the man for forensic purposes, directed the investigations and suggested the clinical diagnosis on the woman.

Early signet ring cell carcinoma arising from colonic adenoma: the molecular profiling supports the adenoma-carcinoma sequence.

Among colorectal cancers, the prevalence of signet ring cell carcinoma (SRCC) is lower than 1%; to date, only 6 cases of early SRCCs arising in colonic adenoma have been reported. In spite of the well-established understanding of the phenotypic and genetic changes occurring in conventional colonic carcinogenesis, the molecular landscape of colon SRCC is still far to be elucidated. We describe the histologic and immunohistochemical phenotype and the molecular profile of a case of intramucosal SRCC developed within a 4.5-cm large sigmoid adenoma. The DNA sequencing of the 2 microdissected neoplastic components (adenomatous and SRCC) showed the same G12V KRAS mutation. Interestingly, although the adenomatous epithelium showed unequivocal p53 overexpression, no signet ring cancer cells featured p53 nuclear immunostain. This molecular pattern supports the unique histogenesis of the 2 coexisting neoplastic oncotypes, also suggesting that the signet ring cell component is derived from the molecular de-differentiation (p53 loss) of the preexisting adenomatous lesion.

YAP immunoreactivity is directly related to pilomatrixoma size and proliferation rate.

Organ size regulation is a highly coordinated process involving complex mechanisms. Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif, also known as WWTR1 (TAZ) have recently been linked to organ size determination and cell proliferation. Pilomatrixoma (PM) is a benign tumor of the adnexal appendages with a certain degree of differentiation toward the matrix of the hair follicle. PM presents as a dermal nodule that usually ranges from 0.5 to 2 cm, rarely exceeding 3 cm. We recently observed a case of unusual "giant" (6.5 cm) PM. Our hypothesis was that YAP and TAZ could be related to PM growth. We analyzed YAP and TAZ immunohistochemical expression in the giant and in ten usual size PMs in relation with tumor size and proliferation rate. YAP nuclear expression was remarkably higher in the giant PM in comparison with usual size PMs and statistically correlated, in a direct manner, with size and proliferation rate of PMs. Contrariwise, TAZ nuclear expression seemed stochastic. Our findings suggest that YAP could play a role in PM growth.