Guidelines for Handling of Cytological Specimens in Cancer Genomic Medicine.

Rapid advances are being made in cancer drug therapy. Since molecularly targeted therapy has been introduced, personalized medicine is being practiced, pathological tissue from malignant tumors obtained during routine practice is frequently used for genomic testing. Whereas cytological specimens fixed mainly in alcohol are considered to be more advantageous in terms of preservation of the nucleic acid quality and quantity. This article is aimed to share the information for the proper handling of cytological specimens in practice for genomic medicine based on the findings established in "Guidelines for Handling of Cytological Specimens in Cancer Genomic Medicine (in Japanese)" published by the Japanese Society of Clinical Cytology in 2021. The three-part practical guidelines are based on empirical data analyses; Part 1 describes general remarks on the use of cytological specimens in cancer genomic medicine, then Part 2 describes proper handling of cytological specimens, and Part 3 describes the empirical data related to handling of cytological specimens. The guidelines indicated proper handling of specimens in each fixation, preparation, and evaluation.

A quantitative evaluation method utilizing the homology concept to assess the state of chromatin within the nucleus of lung cancer.

Homology is a mathematical tool to quantify "the contact degree", which can be expressed in terms of Betti numbers. The Betti numbers used in this study consisted of two numbers, b0 (a zero-dimensional Betti number) and b1 (a one-dimensional Betti number). We developed a chromatin homology profile (CHP) method to quantify the chromatin contact degree based on this mathematical tool. Using the CHP method we analyzed the number of holes (surrounded areas = b1 value) formed by the chromatin contact and calculated the maximum value of b1 (b1MAX), the value of b1 exceeding 5 for the first time or Homology Value (HV), and the chromatin density (b1MAX/ns2). We attempted to detect differences in chromatin patterns and differentiate histological types of lung cancer from respiratory cytology using these three features. The HV of cancer cells was significantly lower than that of non-cancerous cells. Furthermore, b1MAX and b1MAX/ns2 showed significant differences between small cell and non-small cell carcinomas and between adenocarcinomas and squamous cell carcinomas, respectively. We quantitatively analyzed the chromatin patterns using homology and showed that the CHP method may be a useful tool for differentiating histological types of lung cancer in respiratory cytology.

A case of clear cell adenocarcinoma arising from the urethral diverticulum: Utility of urinary cytology and immunohistochemistry.

Carcinomas rarely arise from the urethral diverticulum. In this report, we present a case of clear cell adenocarcinoma arising from the urethral diverticulum. A 42-year-old woman complained of bloody discharge and lower back pain. Imaging studies showed a tumor involving the region surrounding the urethra and cystourethroscopy showed papillary and villous tumors in the urethral diverticula. Cytology of the urine sediment showed papillary or spherical clusters of atypical cells, some of which had clear abundant cytoplasm and formed mirror ball-like clusters, suggesting adenocarcinoma. Although histological diagnosis was indeterminate by biopsy and transurethral resection (TUR) because of absence of stromal invasion, surgically resected specimen via cysturethrectomy revealed that the tumor was clear cell carcinoma. Urinary cytological findings and immunohistochemical analysis for CD15, Ki-67, and p53 might be useful for accurate diagnosis of clear cell adenocarcinoma that arises from the urethral diverticulum when sufficient materials are not available by biopsy and TUR.

Detection of epidermal growth factor receptor mutations in lung adenocarcinoma cytological specimens by immunocytochemistry.

Tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR) improve the survival of patients with lung adenocarcinoma, and determine the EGFR mutation status before treatment is necessary. In contrast to biopsy samples, cytological specimens are obtained less invasively and are useful for EGFR mutation analyses. Recently, novel antibodies against two major EGFR mutations were developed: SP111, which is specific for the E746-A750 deletion in exon 19; and SP125, which is specific for the L858R mutation. To the best of our knowledge, no study has evaluated cytological specimens using the two novel antibodies, thus their specificity and sensitivity were examined in surgical resection, and cytological lung adenocarcinoma samples in the present study. Previous screening for EGFR mutation status by molecular testing identified delE746-A750 in 3 cases and the L858R mutation in 7 cases; the other cases did not have the L858R or the delE746-A750 mutation. Using a four-grade scoring system (score 0 to 3+), the immunohistochemistry (IHC) and immunocytochemistry (ICC) results were compared with those of molecular testing. Using a score of ≥2 as positive, IHC and ICC using SP111 demonstrated sensitivities of 100 and 33.3%, and specificities of 100 and 100%, respectively. IHC and ICC using SP125 revealed sensitivities of 100 and 71.4%, and specificities of 100 and 100%, respectively. Therefore, screening for EGFR mutations by ICC may facilitate therapeutic decision-making, particularly in medical centers that are unable to perform molecular testing.

Classical type and blastoid variant mantle cell lymphoma in the same lymph node: Histology and cytological findings from a touch imprint specimen.

Blastoid variant (BV) is one of the aggressive variants of mantle cell lymphoma (MCL). BV-MCL is defined by its blastic cytomorphology. Previous studies using sequential biopsies in cases with MCL have demonstrated that classical type MCL (C-MCL) often transforms or relapses as an aggressive variant, but a histopathological transition from C-MCL to an aggressive MCL variant in the same pathological specimen has been shown in only a limited number of the cases. We present a case of MCL in which a histological transition between C-MCL and BV-MCL was observed in the same lymph node. A 53-year-old man presented with a submandibular tumor. Touch imprint cytology revealed a monotonous proliferation of large blastic lymphoid cells. Histology revealed a transition between a large lymphoid cell component and small foci of small- to medium-sized cell component within the tumor. Both components were CD5(+), CD10(-), CD20(+), cyclin D1(+), and SOX11(+) on immunohistochemistry. Fluorescent in situ hybridization revealed the translocation of IgH/BCL1 locus. These findings led to a final diagnosis of BV-MCL with coexistent C-MCL. The present case suggests the existence of a pathogenetic pathway of MCL from C-MCL to BV-MCL. Because it is important to accurately identify BV-MCL for prognostication, appropriate ancillary diagnostic tools should be used in suspected cases. Diagn. Cytopathol. 2017;45:364-370. © 2016 Wiley Periodicals, Inc.

A case of blastic plasmacytoid dendritic cell neoplasm: cytomorphological findings of the touch imprint specimen of lymph node.

The patient is a 75-year-old man with axillary lymphadenopathy presenting an indurated papule on his buttock. Touch imprint cytology of the biopsied axillary lymph node revealed the monotonous appearance of medium-sized tumor cells. The nuclei had a slightly irregular contour, finely dispersed chromatin, and a conspicuous nucleolus. Some tumor cells had intracytoplasmic microvacuoles. Immunohistochemistry of the imprint specimens showed that the tumor cells were positive for CD56 and CD123. Histological diagnosis of the lesion was blastic plasmacytoid dendritic cell neoplasm (BPDCN). Epstein-Barr virus-encoded RNAs were not detected in the tumor cells. Neither immunoglobulin heavy chain genes nor T- cell receptor genes was clonally rearranged. BPDCN should be strongly considered during the differential diagnosis of CD56-positive neoplasms of the skin. We demonstrated a possible contribution of the cytomorphological and immunohistochemical findings of the touch imprint specimens to the diagnosis of BPDCN.