Skin Involvement by Hematological Neoplasms with Blastic Morphology: Lymphoblastic Lymphoma, Blastoid Variant of Mantle Cell Lymphoma and Differential Diagnoses.

Hematological neoplasms sharing a blastic morphology may involve the skin. The skin may be either the primary site of occurrence of hematological malignancies with blastic features or cutaneous lesions are the first manifestation of an underlying systemic malignancy. The assessment of skin biopsies of hematological neoplasms with blastic features poses diagnostic problems and requires expert hematopathologists considering a wide range of differential diagnoses. The precise diagnosis of diseases sharing blastic features but with different outcomes and requiring distinct therapies is essential for patient management. The present paper mainly focuses on cutaneous involvement of the blastoid variant of mantle cell lymphoma and lymphoblastic lymphoma of B-cell or T-cell origin. The relevant literature has been reviewed and the clinical aspects, pathological features, prognosis, and therapy of both blastoid mantle cell lymphoma and lymphoblastic lymphoma involving the skin are discussed. A focus on other hematological entities with blastic features, which may involve the skin, to be taken into consideration in differential diagnosis is also given.

Pathologists' assistants, an essential healthcare workforce: the experience of a surgical pathology department in Italy.

AIMS: The progressive increase of both the workload and the complexity of laboratory procedures, along with shortage of staff, has made evident the need to increase the efficiency in the pathology departments. To support the pathologists, a new technical professional role, the pathologists' assistant (PA), has been introduced. METHODS: We decided to carry out a retrospective analysis on PAs' performance. This was compared with that of junior/senior pathologists in the amount and type of surgical specimens examined, the number of lymph node retrieved in colorectal resections, the number of cases needing a second grossing procedure and the average time spent in grossing. As the COVID-19 pandemic period in fact resulted in a dramatic reduction of histological cases in our department, we divided PA activities into two periods, according to the COVID-19 pandemic. RESULTS: 'Simple' specimens made up the majority (92%) of the specimens examined by PAs in pre-COVID-19 period while 'complex' specimens, often neoplastic, represented the minor part (7%). However, 'simple' specimens dropped to 81% and 'complex' specimens rose to 18% in the COVID-19 period, when PAs had the chance to test themselves with more complicated surgical samples, under the supervision of a pathologist. Lymph node retrieval rate and average time spent in grossing are in line with literature data and confirm that PAs performance is comparable with pathologists' one, in selected settings. CONCLUSION: In our experience, PA has represented a fundamental time-saving resource for the pathologists, who can devote time almost exclusively to diagnostic reporting.

Acute Radiation Colitis after Preoperative Short-Course Radiotherapy for Rectal Cancer: A Morphological, Immunohistochemical and Genetic Study.

Preoperative radiotherapy is a widely accepted treatment procedure in rectal cancer. Radiation-induced changes in the tumor are well described, whereas less attention has been given to the non-neoplastic mucosa. Our aim is to provide a detailed analysis of the morphological features present in non-neoplastic mucosa that pathologists need to be familiar with, in order to avoid misdiagnosis, when evaluating rectal cancer specimens of patients preoperatively treated with radiotherapy, especially with short-course regimen. We compared 2 groups of 95 rectal cancer patients treated preoperatively with either short-course (45 patients) or long-course radiotherapy (50 patients). Depending on the type of protocol, different histopathological features, in terms of inflammation, glandular abnormalities and endocrine differentiation were seen in the non-neoplastic mucosa within the irradiated volume. Of note, features mimicking dysplasia, such as crypt distortion, nuclear and cytoplasmic atypia of glandular epithelium, were identified only in the short-course group. DNA mutation analysis, using a panel of 56 genes frequently mutated in cancer, and p53 immunostaining were performed on both tumor and radiation-damaged mucosa in a subset of short course cases. Somatic mutations were identified only in tumors, supporting the concept that tissues with radiation-induced "dysplastic-like" features are not genetically transformed. Pathologists should be aware of the characteristic morphological changes induced by radiation. The presence of features simulating dysplasia in the group treated with short-course radiotherapy may lead to serious diagnostic mistakes, if erroneously interpreted. Next generation sequencing (NGS) analysis further validated the morphological concept that radiation-induced abnormalities do not represent pre-neoplastic lesions.