Two recurrent types of IGH::5' BCL2 breakpoints representing cytogenetic ins(14;18)(q32;q21q21) and t(14;18)(q32;q21), mediated by the VDJ and class switch recombination processes, respectively.

We describe two types of IGH::BCL2 breakpoints involving the 5' region of BCL2 (5' BCL2). One was ins(14;18)(q32;q21q21) observed in 2 follicular lymphoma (FL) cases, in which IGH was cleaved at 3' of IGHD and 5' of IGHJ and BCL2 was cleaved at 5' BCL2 and downstream regions, and a 281- or 201-kilobase pair fragment containing the BCL2 protein-coding sequences was invertedly inserted into IGH. In another type observed in 2 FL and 2 chronic lymphocytic leukemia (CLL) cases, breakage and reunion occurred within the switch region associated with IGHM (Sµ) and 5' BCL2, creating IGH Sµ::5' BCL2 fusion sequences on der(18)t(14;18)(q32;q21). The former is considered to be mediated by VDJ-recombination, while the latter by the class switch recombination process. There were no particular features in FL or CLL cases with IGH::5' BCL2 breakpoints compared with those with t(14;18)(q32;q21)/IGH::BCL2 involving the 3' breakpoint cluster regions.

Deep learning-based assay for programmed death ligand 1 immunohistochemistry scoring in non-small cell lung carcinoma: Does it help pathologists score?

Several studies have developed various artificial intelligence (AI) models for immunohistochemical analysis of programmed death ligand 1 (PD-L1) in patients with non-small cell lung carcinoma; however, none have focused on specific ways by which AI-assisted systems could help pathologists determine the tumor proportion score (TPS). Herein, we developed an AI model to calculate the TPS of the PD-L1 22C3 assay and evaluated whether and how this AI-assisted system could help pathologists determine the TPS and analyze how AI-assisted systems could affect pathologists' assessment accuracy. We assessed the four methods of the AI-assisted system: 1) and 2) pathologists first assessed and then referred to automated AI scoring results (1, positive tumor cell percentage; 2, positive tumor cell percentage and visualized overlay image) for a final confirmation, and 3) and 4) pathologists referred to the automated AI scoring results (3, positive tumor cell percentage; 4, positive tumor cell percentage and visualized overlay image) while determining TPS. Mixed model analysis was used to calculate the odds ratios (ORs) with 95% confidence intervals for AI-assisted TPS 1) to 4) compared with pathologists' scoring. For all 584 samples of tissue microarray, the OR for AI-assisted TPS 1) to 4) was 0.94-1.07 and not statistically significant. Of them, we found 332 cases of discordant cases, on which the pathologists' judgments were inconsistent; the ORs for AI-assisted TPS 1), 2), 3), and 4) were 1.28 (1.06-1.54, p = 0.012), 1.29 (1.06-1.55, p = 0.010), 1.28 (1.06-1.54, p = 0.012), and 1.29 (1.06-1.55, p = 0.010), respectively, which were statistically significant. For discordant cases, the OR for each AI-assisted TPS compared with the others was 0.99-1.01 and not statistically significant. This study emphasized the usefulness of the AI-assisted system for cases wherein pathologists had difficulty determining the PD-L1 TPS.

Insulin-like Growth Factor II mRNA-binding Protein 3 is a Highly Sensitive Marker for Intravascular Large B-cell Lymphoma: Immunohistochemical Analysis of 152 Pathology Specimens From 88 Patients.

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of aggressive extranodal large B-cell lymphoma characterized by the selective growth of lymphoma cells within the lumina of blood vessels, particularly capillaries. IVLBCL lacks mass formation, and its diagnosis can be challenging. We analyzed the utility of insulin-like growth factor II mRNA-binding protein 3 (IMP3) immunohistochemistry for IVLBCL diagnosis in various organs. Double staining with paired box 5 (PAX5) was performed for validation. Overall, 152 pathological specimens (111 positive and 41 negative for IVLBCL) obtained from 88 patients with a diagnosis of IVLBCL were stained for IMP3 and IMP3/PAX5. As negative controls, 40 pathology specimens from 38 patients with no history of IVLBCL or other B-cell lymphomas were stained for IMP3, which comprised 31 benign pathological specimens from 29 patients in whom malignancy was suspected, 7 cases of appendicitis with intravascular and/or intralymphatic lymphoid proliferations, and 2 cases of intravascular natural killer/T-cell lymphoma. All mononuclear cells with cytoplasmic staining were considered positive for IMP3 expression, but expression restricted to germinal center B cells was excluded from evaluation. All 111 IVLBCL pathological specimens were positive for IMP3 and IMP3/PAX5. In addition, 11 of the 41 specimens originally diagnosed as IVLBCL-negative showed IMP3/PAX5 double-positive cells, raising the suspicion of IVLBCL. However, of the 40 negative control samples, IMP3-positive non-germinal center B cells were detected in only 2 samples (P= 0.0131) and no intravascular IMP3-positive B cells suspicious for IVLBCL were identified. Altogether, IMP3 immunohistochemistry is a highly sensitive marker of IVLBCL and can be a helpful adjunct for IVLBCL diagnosis.

Diverse B-cell tumors associated with t(14;19)(q32;q13)/IGH::BCL3 identified by G-banding and fluorescence in situ hybridization.

We characterized 5 B-cell tumors carrying t(14;19)(q32;q13) that creates the IGH::BCL3 fusion gene. The patients' ages ranged between 55 and 88 years. Two patients presented with progression or recurrence of B-cell chronic lymphocytic leukemia (B-CLL)/small lymphocytic lymphoma (SLL), two with diffuse large B-cell lymphoma (DLBCL) of non-germinal center B-like phenotype, and the remaining one with composite angioimmunoblastic T-cell lymphoma and Epstein-Barr virus-positive DLBCL. The presence of t(14;19)(q32;q13) was confirmed by fluorescence in situ hybridization (FISH), showing colocalization of 3' IGH and 3' BCL3 probes on der(14)t(14;19) and 5' BCL3 and 5' IGH probes on der(19)t(14;19). One B-CLL case had t(2;14)(p13;q32)/IGH::BCL11A, and 2 DLBCL cases had t(8;14)(q24;q32) or t(8;11;14)(q24;q11;q32), both of which generated IGH::MYC by FISH, and showed nuclear expression of MYC and BCL3 by immunohistochemistry. The IGH::BCL3 fusion gene was amplified by long-distance polymerase chain reaction in 2 B-CLL/SLL cases and the breakpoints occurred immediately 5' of BCL3 exon 1 and within the switch region associated with IGHA1. The 5 cases shared IGHV preferentially used in B-CLL cells, but the genes were unmutated in 2 B-CLL/SLL cases and significantly mutated in the remaining 3. B-cell tumors with t(14;19)(q32;q13) can be divided into B-CLL/SLL and DLBCL groups, and the anatomy of IGH::BCL3 in the latter may be different from that of the former.

Histopathological significance of connective tissue disease-associated interstitial lung disease in transbronchial lung cryobiopsy specimens.

Differentiating between idiopathic interstitial pneumonia (IIP) and secondary interstitial pneumonia, particularly connective tissue disease-associated interstitial lung disease (CTD-ILD), can be challenging histopathologically, and there may be discrepancies among pathologists. While surgical lung biopsy has traditionally been considered the gold standard for diagnosing interstitial pneumonia, the usefulness of transbronchial lung cryobiopsy (TBLC) has been reported. If TBLC could effectively distinguish between primary and secondary diseases, it would provide a less invasive option for patients. The aim of this study was to identify specific pathologic findings in TBLC specimens that could assist in distinguishing CTD-ILD from IIP. A total of 93 underwent TBLC at Tenri Hospital between 2018 and 2022. We retrospectively reviewed cases of CTD-ILD exhibiting a nonspecific interstitial pneumonia (NSIP) pattern (CTD-NSIP) and cases of NSIP with an unknown etiology (NSIP-UE), as determined through multidisciplinary discussion. Nineteen patients with CTD-NSIP and 26 patients with NSIP-UE were included in the study for clinicopathological analysis. The CTD-NSIP group had a significantly higher proportion of female patients compared to the NSIP-UE group (79% vs. 31%; p = 0.002). The presence of both fresh and old intraluminal fibrosis within the same TBLC specimen was significantly more frequent in CTD-NSIP group than in the NSIP-UE group (p = 0.023). The presence of an NSIP pattern with co-existing fresh and old intraluminal fibrosis in TBLC specimens raised suspicion for CTD-ILD.

Intravascular Large B-cell Lymphoma Presenting as Pulmonary Ground-glass Nodules That Progressed Slowly over Several Months with No Overt Symptoms.

A 74-year-old man with no overt symptoms was referred for a chest computed tomography (CT) that revealed multiple bilaterally pulmonary ground-glass nodules (GGNs) with subtle changes in size over eight months. Surgical lung biopsies were performed in the left upper lobe. A pathologic study confirmed the intravascular large B-cell lymphoma (IVLBCL). This lesion was a nodule-like cluster of atypical cells, meaning that it had been localized for several months. Pulmonary IVLBCL may form focal lesions presenting as GGN on chest CT and progress slowly without apparent symptoms.

Comprehensive analyses of the clinicopathological features and genomic mutations of combined hepatocellular-cholangiocarcinoma.

AIM: Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer that has two different tumor phenotypes in a single tumor nodule. The relationship between genetic mutations and clinicopathological features of cHCC-CCA remains to be elucidated. METHODS: Whole-exome sequencing analyses were carried out in 13 primary and 2 recurrent cHCC-CCAs. The whole-exome analyses and clinicopathological information were integrated. RESULTS: TP53 was the most frequently mutated gene in this cohort, followed by BAP1, IDH1/2, and NFE2L2 mutations in multiple cases. All tumors with diameters <3 cm had TP53 mutations. In contrast, six of seven tumors with diameters ≥3 cm did not have TP53 mutations, but all seven tumors had mutations in genes associated with various pathways, including Wnt, RAS/PI3K, and epigenetic modulators. In the signature analysis, the pattern of mutations shown in the TP53 mutation group tended to be more similar to HCC than the TP53 nonmutation group. Mutations in recurrent cHCC-CCA tumors were frequently identical to those in the primary tumor, suggesting that those tumors originated from identical clones of the primary cHCC-CCA tumors. Recurrent and co-occurrent HCC tumors in the same patients with cHCC-CCA had either common or different mutation patterns from the primary cHCC-CCA tumors in each case. CONCLUSIONS: The study suggested that there were two subtypes of cHCC-CCA, one involving TP53 mutations in the early stage of the carcinogenic process and the other not involving such mutations. The comparison of the variants between primary and recurrent tumors suggested that cHCC-CCA was derived from an identical clone.

MYC/BCL2 double- and MYC/BCL2/BCL6 triple-hit follicular lymphomas associated with t(8;14;18)(q24;q32;q21).

We describe two follicular lymphoma (FL) patients with MYC/BCL2 double- and MYC/BCL2/BCL6 triple-hit translocations. The first patient (case 1) was a man in his 30s who presented with stage IV disease with leukemic manifestation. The second patient (case 2) was a man in his 60s who presented with relapsed FL, but his disease was in a limited stage. Histopathology of the lymph node biopsies revealed grade 3A FL in both cases. MYC positivity and the Ki-67-labeling index were 60-70 and 20% in case 1 and 30 and 50% in case 2, respectively. G-banding revealed t(8;14;18)(q24;q32;q21) in both cases and fluorescence in situ hybridization using MYC, IGH, and BCL2 break-apart probes confirmed t(8;14;18)(+5'BCL2,-3'MYC;+3'MYC,-5'IGH;+5'IGH,-5'BCL2). In case 2, additional materials of der(8)t(8;14;18) were duplicated and translocated to chromosome Y, and t(3;16)(q27;p13)/BCL6::CIITA was identified. We obtained BCL2-major breakpoint region::IGHJ5::IGHG1 and MYC exon 2::IGHA2 fusion sequences by long-distance polymerase chain reaction in case 1, and proposed that t(8;14;18) was generated by two-step translocations and that BCL2::IGH and MYC::IGH involved the same IGH allele. Both patients responded to the standard chemotherapy for FL. We suggest that the presence of t(8;14;18) in FL does not immediately indicate high-grade transformation and aggressive clinical behavior requiring intensive chemotherapy.

Two cases of primary diffuse large B-cell lymphoma of the CNS associated with t(8;14)(q24;q32) or t(3;14)(q27;q32) identified by G-banding and fluorescence in situ hybridization applied to metaphase spreads.

We describe two patients with primary diffuse large B-cell lymphoma of the central nervous system (PCNS-DLBCL). The first patient (case 1) was a woman in her late 70s who presented with a tumor in the left frontal lobe, whereas the second patient (case 2) was a man in his early 70s who presented with a left frontal lobe tumor associated with intratumoral hemorrhage. The histopathology of the tumor specimen disclosed the proliferation of large cells with centroblastic (case 1) or immunoblastic/plasmablastic (case 2) cytomorphology and an accumulation of the tumor cells within the perivascular space. The cells in both cases were positive for CD20, CD79a, BCL6, IRF4/MUM1, MYC, and BCL2 and negative for CD5 and CD10. G-banding revealed t(8;14)(q24;q32) in case 1, and the tetraploid-range karyotype including two or three copies of der(3)t(3;14)(q27;q32) and der(14)t(3;14)(q27;q32) in case 2. Fluorescence in situ hybridization applied to metaphase spreads confirmed colocalization of MYC and IGH (case 1) and BCL6 and IGH (case 2) hybridization signals on the relevant derivative chromosomes. Case 1 carried the MYD88L265P mutation. This case report provides clear evidence for the occurrence of t(8;14)(q24;q32) and t(3;14)(q27;q32) in PCNS-DLBCL using metaphase-based cytogenetic analysis.

t(9;14)(p13;q32)/PAX5-IGH translocation as a secondary cytogenetic abnormality in diffuse large B-cell lymphoma.

A 75-year-old man presented with an ileocecal tumor composed of diffuse proliferation of large cells with immunoblastic morphology. Lymphoma cells were positive for CD20, CD79a, IRF4/MUM1, and BCL2, negative for CD5, CD10, and MYC, and partially positive for BCL6. PAX5 was positive with variable staining intensity among the cell nuclei. The V-D-J sequence of IGH showed the mutated configuration. The G-banding karyotype demonstrated two cytogenetic clones with or without t(9;14)(p13;q32), but the two shared other structural and numerical abnormalities. Fluorescence in situ hybridization using PAX5 and IGH probes confirmed the presence or absence of t(9;14)(p13;q32)/PAX5-IGH in each clone. The breakpoints of t(9;14)(p13;q32) were mapped 2,170 bp upstream of the coding region of PAX5 alternative exon 1B and within the IGHJ6-Eµ enhancer intron of IGH. It is suggested that t(9;14)(p13;q32) in this case was a secondary cytogenetic abnormality and the translocation is not necessarily involved in initial malignant transformation of B-cells but can occur later during the course of diffuse large B-cell lymphoma.

[A Case of Rapidly Growing Sarcomatoid Urothelial Carcinoma of the Renal Pelvis and Ureter].

75 year-old man followed up regularly for the treatment of lung cancer came to our hospital with a chief complaint of general malaise. Blood test results showed deterioration in the renal function, and computed tomography (CT) confirmed left hydronephrosis. He was admitted to the hospital with the diagnosis of obstructive pyelonephritis. Despite antibiotic therapy after the left ureteral stent placement, CT on day 19 of hospitalization showed an enlarged soft tissue shadow along the renal pelvis and ureter, which was suspected to be peripelvic urinary extravasation caused by stent occlusion. We decided that conservative treatment would not improve his condition and conducted surgical therapy considering the possibility of malignancy. Intraoperatively, viscous and fragile tumor affected the renal pelvis and ureter. The operation resulted in left nephrectomy because radical resection was impossible. The pathological diagnosis was sarcomatoid urothelial carcinoma of the renal pelvis with ureter origin. He died due to multipleorgan failureon day 20 after theope ration. Were port a caseof sarcomatoid urothelial carcinoma in the upper urinary tract that was difficult to diagnose preoperatively based on imaging studies.

High-grade salivary gland carcinoma with the ETV6-NTRK3 gene fusion: A case report and literature review of secretory carcinoma with high-grade transformation.

Secretory carcinoma or mammary analog secretory carcinoma is an entity of salivary gland carcinoma that is characterized by the ETV6-NTRK3 gene fusion. Although it is generally considered to be a low-grade malignancy, some cases of secretory carcinoma with high-grade transformation (SCHG) have been reported. We herein describe a case of SCHG composed almost exclusively of the high-grade component. The patient presented with a growing mass in the buccal mucosa and underwent surgery. Tumor cells showing high-grade nuclear atypia were arranged in solid or cribriform nests with comedo-like necrosis. A differential diagnosis included high-grade salivary gland carcinoma, such as salivary duct carcinoma. Immunohistochemically, tumor cells were focally positive for S-100 and negative for mammaglobin and showed nuclear positivity for pan-Trk. A reverse transcription polymerase chain reaction assay showed that the tumor harbored the ETV6-NTRK3 gene fusion. A histological review of microscopic slides of the tumor did not reveal a typical secretory carcinoma component, except for a very focal area. We ultimately diagnosed this tumor as SCHG. This case underscores the importance of recognizing the histological spectrum of SCHG and the utility of pan-Trk immunohistochemistry to detect secretory carcinoma, which may be targeted by tyrosine kinase inhibitors.

Prognostic significance of cribriform adenocarcinoma of the lung: validation analysis of 1,057 Japanese patients with resected lung adenocarcinoma and a review of the literature.

BACKGROUND: Cribriform-predominant adenocarcinoma of the lung (Cribri-ADC) is a recently described tumor growth pattern. However, its prognostic impact has not been clearly determined. We analyzed the data of a series of 1,057 Japanese patients with resected lung adenocarcinoma to identify the clinical significance of Cribri-ADC. METHODS: Cribriform pattern (Cribri-p) is defined as invasive back-to-back fused tumor glands with poorly formed glandular spaces or invasive tumor nests comprising tumors cells that produced glandular lumina. We investigated the correlations of Cribri-p and Cribri-ADC with clinicopathological factors as well as disease-free survival (DFS) and overall survival (OS). RESULTS: Cribri-p was present in 217 patients (20.5%) and Cribri-ADC was determined in 25 patients (2.4%). Cribri-p was associated with larger tumor size, pleural invasion, vascular invasion, lymphatic invasion, and spreading through air spaces (STAS) (all, P<0.0001). Cribri-ADC was associated with younger age (P=0.019), vascular invasion (P=0.0025), STAS (P<0.0001), and ALK rearrangement (P=0.012). The DFS curve of patients with Cribri-ADC was identical to that of patients with solid adenocarcinoma; however, the OS curve was located between that of patients with papillary and acinar adenocarcinoma. Of the 10 patients who had tumor recurrences, eight had EGFR mutations or ALK rearrangement, six of whom achieved relatively long survival (median, 64.6, range, 37.4-113 months) following treatment with tyrosine kinase inhibitors (TKIs). In multivariate analysis, Cribri-ADC was not an independent prognostic factor of either recurrence or death. CONCLUSIONS: Cribri-ADC is associated with a higher risk of recurrence; however, most patients can be successfully treated with TKIs.

A rare case of primary angiosarcoma of the anterior mediastinum.

A 32-year-old male patient was initially diagnosed with fibrosing mediastinitis. The patient subsequently developed severe dyspnea and was further diagnosed with constrictive pericarditis due to the extent of fibrosing mediastinitis around the heart. Therefore, the patient underwent surgical resection of the fibrotic tissue in the anterior mediastinum including the pericardium and the pleura. Postoperative histological and immunohistochemical analyses revealed angiosarcoma. Seven years after the diagnosis, he is still alive. Herein, we report a case of atypical primary angiosarcoma of the anterior mediastinum causing constrictive pericarditis and restrictive pulmonary dysfunction.

Clinicopathological features and recurrence patterns of combined hepatocellular-cholangiocarcinoma.

BACKGROUND: Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a primary liver carcinoma with both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) components. We examined the clinicopathological characteristics and recurrence patterns of cHCC-CCA. Because of the rarity of cHCC-CCA, its etiology, clinicopathological features, and prognosis in comparison with other primary liver carcinoma remain unknown. Its recurrence pattern and sites in particular also need to be elucidated. METHODS: All patients who underwent hepatectomy for primary liver malignancies between 2005 and 2015 were retrospectively included in this study. RESULTS: Eight hundred and ninety-four hepatectomies were performed. Nineteen cases of cHCC-CCA (2.1%) in 16 patients were enrolled. Three patients underwent re-hepatectomy. The background of hepatitis viruses and tumor marker patterns of cHCC-CCA were similar to those of HCC and dissimilar to those of intrahepatic CCA (iCCA). Biliary invasion was common in cHCC-CCA and iCCA. The 5-year overall survival values of the cHCC-CCA, HCC, and iCCA patients were 44.7%, 56.6%, and 38.5%, respectively. The 5-year recurrence-free survival values of the cHCC-CCA, HCC, and iCCA patients were 12.2%, 28.7%, and 32.9%, respectively. The liver was the most common recurrence site. Unlike HCC, however, the lymph node was the second-most common recurrence site in both cHCC-CCA and iCCA. Pathological samples of the recurrent lesions were obtained in six patients, and four had cHCC-CCA recurrence pathologically. CONCLUSION: cHCC-CCA had a mixture of characteristics of HCC and iCCA. Many cases of cHCC-CCA remained cHCC-CCA pathologically even after recurrence.

Solitary recurrence of prostate cancer surrounded by seminal vesicle/vas deferens-like epithelium.

INTRODUCTION: Clinical recurrence of prostate cancer after curative treatment with a limited number of metastases is often termed as oligorecurrence. We report a case of solitary recurrence of prostate cancer surrounded by epithelium of the seminal vesicle or vas deferens. CASE PRESENTATION: A 54-year-old man diagnosed with localized prostate cancer underwent radiation therapy. Six years later, imaging studies detected a solitary recurrence. We performed metastasectomy, and histopathological examination revealed the metastatic lesion surrounded by the epithelium of the seminal vesicle or vas deferens. Surgical resection achieved a complete biochemical response. CONCLUSION: We presented with a case of prostate cancer metastasis surrounded by the epithelium of the seminal vesicle or vas deferens.

Living donor liver transplantation for combined hepatocellular-cholangiocarcinoma: A case series of four patients.

INTRODUCTION: Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver carcinoma whose components include both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). Indications for liver transplantation for cHCC-CCA remain controversial. CASE PRESENTATIONS: Four patients underwent living donor liver transplantation (LDLT) for cHCC-CCA. All patients had multiple tumor nodules preoperatively diagnosed as HCC. Postoperative pathological examinations revealed that one of the tumors was cHCC-CCA. Cases 1 and 2 underwent LDLT for cirrhosis with HCC tumors that met Milan criteria. Case 3 underwent LDLT for recurrent HCC tumors with nonalcoholic steatohepatitis. Although the preoperative examinations showed that the patient met the Kyoto, but not Milan criteria, postoperative pathological examinations revealed that the patient did meet Milan criteria. The three patients who met Milan criteria on postoperative pathological examination had no recurrences after LDLT. Case 4 had multiple tumors with alcoholic liver cirrhosis. Although the preoperative examinations showed that the patient did not meet Milan criteria-but did meet Kyoto criteria-, on postoperative pathological examinations, the patient met neither Millan nor Kyoto criteria. He died of tumor recurrence 15 months after LDLT. DISCUSSION AND CONCLUSIONS: Our experiences suggested that patients who meet Millan or Kyoto criteria experienced acceptable outcomes of LDLT for cHCC-CCA. By itself, cHCC-CCA is not contraindication for liver transplantation.

Large nest micropapillary pattern of lung adenocarcinoma has poorer prognosis than typical floret pattern: analysis of 1,062 resected tumors.

BACKGROUND: A micropapillary pattern (MP-p) is related to poor prognosis in patients with lung adenocarcinoma (L-ADC). In 2015, the WHO defined the MP-p as "papillary tufts forming florets that lack fibrovascular cores and may appear detached from alveolar walls"; however, the sizes of tumor clusters in air space were not mentioned in this classification. METHODS: We evaluated the MP-p dividing the cluster sizes in the air space by reviewing 1,062 cases of resected L-ADCs. We classified MP-p into two types according to cluster size as follows: typical floret MP-p, tumors with small-to-medium-sized clusters (1-20 tumor cells); and large nest MP-p, tumors with large-sized clusters (>20 tumor cells, large nest). We then recorded the frequency of each type and investigated the association between the MP-p type and clinicopathological factors. RESULTS: Twenty-nine percent of L-ADCs (n=308) were MP-p-positive. Typical floret MP-p and large nest MP-p were observed in 244 tumors (22.9%) and 64 tumors (6.0%), respectively. Only 7 additional micropapillary ADCs were detected when we reclassified ADCs in addition to large nest MP-p. Tumors with large nest MP-p showed the highest frequency of node metastasis and worse prognosis compared to those with typical floret MP-p and absent (P<0.001). In multivariate analysis, patients with L-ADC with typical floret MP-p and large nest MP-p showed a higher recurrence rate [hazard ratio (HR): 1.762 (type 1 vs. absent), HR: 2.450 (type 2 vs. absent)]. CONCLUSIONS: Large nest MP-p should be included in the original MP-p and recorded separately.

Temozolomide and etoposide combination for the treatment of relapsed osteosarcoma.

The prognosis of patients with relapsed osteosarcoma is extremely poor and the optimal treatment remains to be identified. Here, we retrospectively analysed the clinical outcomes of nine patients with relapsed osteosarcoma treated with temozolomide/etoposide. Of the two patients who received temozolomide/etoposide as palliative therapy for unresectable tumours, one remained alive with stable disease for >4 years. The remaining seven patients received temozolomide/etoposide as adjuvant therapy following resection of relapsed metastatic disease; of these, one was free from disease for 41 months. Potentially beneficial effects were observed in two of three O6-methylguanine-DNA methyltransferase protein-negative patients, whereas all five O6-methylguanine-DNA methyltransferase-positive patients experienced subsequent relapse. None of the patients experienced severe adverse effects requiring hospitalization. Temozolomide/etoposide is a feasible candidate as salvage therapy for relapsed osteosarcoma. Further studies are needed to verify the utility of O6-methylguanine-DNA methyltransferase protein expression as a biomarker for predicting the response to this treatment.