For staining of ALK protein, the novel D5F3 antibody demonstrates superior overall performance in terms of intensity and extent of staining in comparison to the currently used ALK1 antibody

Primary cutaneous, epidermotropic mycosis fungoides-like presentation: critical appraisal and description of two novel cases, broadening the spectrum of ALK+ T-cell lymphoma

Leading from a two-case series, including two patients receiving a diagnosis of epidermotropic T-cell lymphoma, featuring a mycosis fungoides (MF)-like clinical pattern and ALK expression and molecular alteration, we performed a critical appraisal of ALK+ primary cutaneous T-cell lymphomas (pcTCL). Considering our patients and the literature, 32 cases were retrieved, 7 of which featured an MF-like clinical picture over a 4-to-20-year period. MF-like cases show distinctive histology, comprising a predominantly epidermotropic infiltration of small-to-large, atypical-to-pleomorphic, with few anaplastic cells, negligible-to-intense CD30-expression, and a CD4+/cytotoxic granule+ phenotype. These features should prompt a search for ALK expression captured by the ALK D5F3 clone. Bona fide ALK+ pcTCL is very rare, and existent data suggest the presence of a broader pattern of disease, including instances mimicking MF and/or primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma. The major challenges in dealing with this subset include prodromal phases, misinterpreted as inflammatory dermatosis or parapsoriasis/early phase MF both clinically and histologically, while recognition of its ALK-driven biology is hampered both by the unusual clinic-pathologic pattern of the disease, which stands apart from the classical (i.e., nodal) picture of ALK+ anaplastic large cell lymphoma and by the low sensitivity of ALK1 clone. Data on its optimal management are far from being conclusive: An MF-like approach is currently chosen, but depending on CD30 and, most notably, ALK expression, a targeted therapy could be envisaged in advanced stages, as clinical response to ALK inhibition was documented in one patient.

A rare huge bladder inflammatory myofibroblastic tumor treated by en bloc resection with diode laser: a case report and literature review

Background

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm with malignant potential. Bladder IMT is even rarer and mainly treated by surgical resection However, partial or radical cystectomy would affect the quality of life of patients due to major surgical trauma, and classical TURBT is hard to avoid intraoperative complications including obturator nerve reflex and bleeding etc. Therefore, the safe and effective better choice of surgical approaches become critical to bladder IMT.

Case presentation

A 42-year-old male patient was admitted to the department of urology with persistent painless gross hematuria for more than 10 days without the presentation of hypertension. Preoperative routine urine examination of red blood cells was 7738.9/HPF (normal range ≤ 3/HPF). CTU indicated a space occupying lesion (6.0 cm×5.0 cm) in the left posterior wall of the bladder with heterogeneous enhancement in the excretory phase. MRI also indicated bladder tumor with slightly equal SI on T1WI and mixed high SI on T2WI (6.0 cm×5.1cm×3.5cm) in the left posterior wall of the bladder. En bloc resection of bladder IMT with 1470 nm diode laser in combination of removing the enucleated tumor by the morcellator system was performed. Postoperative pathological examination revealed bladder IMT, with IHC positive for Ki-67 (15-20%), CK AE1/AE3, SMA, and Desmin of bladder IMT and negative for ALK of bladder IMT as well as FISH negative for ALK gene rearrangement. Second TUR with 1470 nm diode laser was performed within 6 weeks to reduce postoperative risk of recurrence due to highly malignant potential for the high expression of Ki-67 (15-20%) and negative ALK in IHC staining. The second postoperative pathology report showed chronic inflammation concomitant with edema of the bladder mucosa without bladder IMT, furthermore no tumor was observed in muscularis propria layer of bladder. No recurrence occurred during the period of 24-month follow-up.

Conclusion

En bloc resection of bladder IMT in combination of the following second transurethral resection with 1470 nm diode laser is a safe and effective surgical approach for the huge bladder IMT with highly malignant potential.

Mediastinal epithelioid inflammatory myofibroblastic sarcoma with the EML4-ALK fusion: A case report and literature review

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is an aggressive subtype of inflammatory myofibroblastic tumour which rarely affects the chest cavity. We, for the first time, report a case of mediastinal EIMS with the EML4-ALK fusion. A young woman presented to our hospital with cough, chest tightness and shortness of breath. Computed tomography (CT) showed a mixed attenuation soft-tissue mass in the right middle and upper mediastinum. Negative results were obtained from bronchoscopy forceps biopsy and endobronchial ultrasound-guided transbronchial fine needle aspiration. CT-guided percutaneous biopsy was finally performed. However, due to the rapidly progressed EIMS that compressed the trachea and right main bronchus, the patient died of respiratory failure 1 day before diagnosis. EIMS progresses rapidly, and an early diagnosis is important. For mediastinal EIMS, CT-guided percutaneous biopsy may be useful. Next-generation sequencing of blood may be instructive to EIMS patients who are intolerant to invasive biopsy.

Comparison of two immunohistochemical staining protocols for ALK demonstrates non-inferiority of a 5A4 clone-based protocol versus an ALK01 clone-based protocol for the diagnosis of ALK + anaplastic large cell lymphoma

Detection of ALK rearrangement and/or expression of the ALK protein is an essential component in the evaluation of many neoplasms. Variability has been reported in the ability of different antibody clones to detect ALK expression. The ALK01 clone is commonly used to detect ALK expression in ALK-positive anaplastic large cell lymphoma (ALK + ALCL). However, this clone has been shown to lack sensitivity when used for solid tumors. The aim of this study was to determine if our high-sensitivity 5A4-based immunohistochemistry protocol is non-inferior to our ALK01-based protocol for the detection of ALK expression in ALK + ALCL. To compare the two protocols, we stained tissue microarrays of 126 hematolymphoid neoplasms and an additional 21 primary cutaneous ALK-negative anaplastic large cell lymphomas with both protocols. All 28 ALK + ALCL samples that were positive for the ALK01 antibody were also positive for the 5A4 clone. Three cases on the tissue microarray that were negative with the ALK01 antibody were clearly positive with the 5A4 antibody. We subsequently stained whole tissue sections of these three cases with the ALK01 antibody and found that these three cases were indeed positive with the ALK01 protocol, suggesting that the absence of staining on the tissue microarray samples was due to a combination of sampling error as well as a dimmer signal with the ALK01 protocol. Our study demonstrates that our 5A4-based protocol is non-inferior to the ALK01 antibody for the diagnosis of ALK-positive anaplastic large cell lymphoma, thus allowing our laboratory to discontinue the use of the ALK01-based protocol.

Uterine inflammatory myofibroblastic tumor

Inflammatory myofibroblastic tumor (IMT) is recognized as a true neoplasm of unknown etiology, but its pathogenesis is related to abnormalities in the ALK gene. This is an uncommon tumor with a wide anatomic distribution and often constitutes a challenging diagnosis owing to its histological similarities with other tumors. Uterine IMTs are rare and their detailed characteristics should be described based on case reports and small case series. Thus, we performed a comprehensive review of the literature showing that uterine IMTs show a wide range of age at diagnosis (median, 39 years), and a symptomatology similar to that of common leiomyomas, only rarely presenting with inflammatory manifestations. IMTs represent 0.1% of "leiomyomas," an estimate that increases to 10% for pregnant women and to 14% for the smooth muscle tumors of uncertain malignant potential (STUMP) category of tumors, implying that tumors excised during pregnancy, STUMPs, and leiomyosarcomas should be systematically screened with ALK immunohistochemistry, as this is a targetable abnormality. Most reported cases are ALK-positive; the fusion partners vary, but in pregnancy-associated tumors, TIMP3 prevails. Almost 25% of the patients will show an aggressive course, and this is associated with older age, non-pregnancy-associated tumors, larger tumors, infiltrative tumor border, absence of abundant inflammation, atypia, important mitotic activity, and necrosis.

High expression of GMNN predicts malignant progression and poor prognosis in ACC

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare endocrine neoplasm, which is characterized by poor prognosis and high recurrence rate. Novel and reliable prognostic and metastatic biomarkers are lacking for ACC patients. This study aims at screening potential prognostic biomarkers and therapeutic targets of ACC through bioinformatic methods and immunohistochemical (IHC) analysis.

METHODS

In the present study, by using the Gene Expression Omnibus (GEO) database we identified differentially expressed genes (DEGs) in ACC and validated these DEGs in The Cancer Genome Atlas (TCGA) ACC cohort. A DEGs-based signature was additionally constructed and we assessed its prognosis and prescient worth for ACC by survival analysis and nomogram. Immunohistochemistry (IHC) was used to verify the relationship between hub gene-GMNN expressions and clinicopathologic outcomes in ACC patients.

RESULTS

A total of 24 DEGs correlated with the prognosis of ACC were screened from the TCGA and GEO databases. Five DEGs were subsequently selected in a signature which was closely related to the survival rates of ACC patients and GMNN was identified as the core gene in this signature. Univariate and multivariate Cox regression showed that the GMNN was an independent prognostic factor for ACC patients (P < 0.05). Meanwhile, GMNN was closely related to the OS and PFI of ACC patients treated with mitotane (P < 0.001). IHC confirmed that GMNN protein was overexpressed in ACC tissues compared with normal adrenal tissues and significantly correlated with stage (P = 0.011), metastasis (P = 0.028) and Ki-67 index (P = 0.014).

CONCLUSIONS

GMNN is a novel tumor marker for predicting the malignant progression, metastasis and prognosis of ACC, and may be a potential therapeutic target for ACC.

Update on Uterine Mesenchymal Neoplasms

This review focuses on recent advances in epithelioid and myxoid uterine mesenchymal neoplasms, a category of tumors whereby diagnostic criteria have been rapidly evolving due to advances in molecular testing. Pertinent clinicopathological and molecular features are highlighted for perivascular epithelioid cell tumors, uterine tumors resembling ovarian sex cord tumors, BCOR/BCORL1-altered high-grade endometrial stromal sarcomas, and inflammatory myofibroblastic tumors. Novel developments in epithelioid and myxoid leiomyosarcomas are briefly discussed, and differential diagnoses with key diagnostic criteria are provided for morphologic mimickers.

Too Sensitive or Just Right?

OBJECTIVES

To compare the performance of the rabbit monoclonal antihuman CD246 antibody (D5F3 clone) with the established ALK1 clone for immunohistochemical assessment of anaplastic large cell lymphoma (ALCL).

METHODS

Archival cases of ALCL (n = 27) were assessed immunohistochemically by use of ALK1 and D5F3 clones under standard Clinical Laboratory Improvement Amendments-compliant conditions. The intensity of cytoplasmic staining (0 = none; 1 = faint; 2 = moderate; 3+ = strong) and proportion of neoplastic cells (0%, <5%, 5%-50%, >50%) were evaluated and compared with clinical ALK break-apart fluorescence in situ hybridization (FISH) assays.

RESULTS

Nine ALCL specimens were positive for ALK expression by ALK1 staining (33%; 1 = 1+; 0 = 2+; 8 = 3+), while 14 were positive by D5F3 staining (48%; 3 = 1+; 1 = 2+; 10 = 3+). Across the cohort, D5F3 staining showed a significantly greater proportion of cells staining positive (P = .02) and greater intensity (P = .03). Of 3 cases positive for D5F3 only with FISH results, none showed rearrangements, although 1 showed copy number gains at the ALK locus in a subset of cells.

CONCLUSIONS

Overall, D5F3 showed greater stain intensity and proportion staining than ALK1 in ALK-positive ALCL cases, which is especially helpful in limited samples. Caution and consideration of orthogonal ALK testing types is recommended, especially for cases with weak or focal staining.

Assessment of ALK Fusions in Uncommon Inflammatory Myofibroblastic Tumors With ALK IHC Positivity but FISH-Equivocal Findings by Targeted RNA Sequencing

CONTEXT.—

Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) are common methods to detect ALK status in inflammatory myofibroblastic tumors (IMTs). However, equivocal ALK FISH signals and inconsistency between FISH and IHC are occasionally observed.

OBJECTIVE.—

To study the inconsistency between FISH and IHC, and clarify ALK status in IMT by targeted RNA sequencing (RNAseq).

DESIGN.—

In this study, 12 consultation cases preliminarily diagnosed as uncommon IMTs with ALK IHC positivity but FISH negativity, plus 3 ALK-positive and 3 ALK-negative IMTs, were re-analyzed by IHC, FISH, and RNAseq.

RESULTS.—

As a result, 1 case with FUS-TFCP2 fusion was detected by RNAseq, which was previously misdiagnosed as IMT. In the other 11 uncommon IMTs, 90.9% (10 of 11) showed equivocal ALK FISH signals, and all were confirmed to harbor ALK fusion by RNAseq, except for 1 failure, suggesting that a low threshold for ALK FISH might be proposed in IMT. Furthermore, RNAseq also identified IGFBP5-ALK in 1 case with ALK IHC positivity but typical FISH negativity, suggesting the possibility of false negatives for ALK FISH. For the typical IMTs, ALK fusion was identified by RNAseq in all 3 ALK-positive IMTs as expected, and additionally FN1-ROS1 fusions were identified in 2 of 3 ALK-negative IMTs.

CONCLUSIONS.—

These findings indicated that RNAseq can simultaneously detect multiple gene fusions and provide fusion forms and breakpoints, which is of great value for differential diagnosis, especially for those uncommon IMTs with equivocal FISH findings, or inconsistency between IHC and FISH.

The extent of expression of thyroid transcription factor 1, cytokeratin 7, and anaplastic lymphoma kinase in lung adenocarcinoma

Background:

New forms of genetic alteration were developed giving a new era of lung adenocarcinoma (AdC) with diverse clinical and pathological features.

Aim and Objectives:

The aim is to investigate the ALK-rearranged gene as one of these genetic alterations in AdC. The role of TTF-1 and CK7 is to exclude the metastases.

Material and Methods:

Paraffin-embedded 50 AdC specimens were cut into 4-mm thick sections and stained with the primary antibody, using an anti-TTF-1 antibody, (all at a 1:200 dilution, mouse monoclonal antibody; Dako, Denmark), anti-CK 7 antibody (DAKO, Carpentaria, CA), and the rabbit monoclonal anti- ALK antibody (D5F3) (Ventana, USA). Positive reactivity was considered as brown nuclear immunostaining for TTF-1 and cytoplasmic for CK 7and both cytoplasmic and nuclear for ALK.

Results:

The median age was 56±2, with male to female ratio 7:3. Forty-four cases revealed a mixed pattern (88%), with focal intraluminal mucin. Forty-one cases (82%) were positive for TTF-1, of these; weak (13; %), moderate (16; %) and strong (12; %). Regarding CK7; 48 cases (96%) were positive; weak (7 cases; 14.5; %), moderate (18 cases; 37.5%) and strong (23 case; 47.9 %) of the positive cases. Regarding D5F3; five cases (10%) were positive; weak (1 case; 20 %), moderate (2 cases; 40 %) and strong (2 cases; 40%) out of the positive cases. Four ALK-positive cases were male and ALK-positive patients ranged from 42-55 years with median 48.

Conclusion:

Despite the incidence of ALk-AdC is uncommon, it might be suspected in lesions of lower age group especially with mucinous foci.

[Immunohistochemical and molecular diagnosis of inflammatory myofibroblastic tumor of the uterus: a literature review and a clinical case]

Inflammatory myofibroblastic tumors of the uterus (uIMT) are rare and difficult to diagnose neoplasms, since the morphological characteristics of this tumor are not specific and are found in other pathological changes. In addition, until recently, specific uIMT markers have not been identified and their diagnostic standards not defined. However, in recent years, there have been more and more studies aimed to identify characteristic morphological, immunohistochemical, and molecular genetic features for the differential diagnosis of uIMT. Recent papers studying uIMT indicate anaplastic lymphoma kinase (ALK) as a potentially reliable marker of uIMT. This communication describes a clinical case of uIMT in a 40-year-old woman who has been preoperatively diagnosed with a large subserous interstitial myomatous nodule. The final diagnosis was made, by analysing a combination of morphological and immunohistochemical signs. This clinical case with a literature review is indicated to consider ALK as a key criterion in the diagnosis of uIMT, as well as the relationship between subsequent treatment and the presence of ALK in the studied tissues.

ALK Immunohistochemistry and Molecular Analysis in Uterine Inflammatory Myofibroblastic Tumor: Proceedings of the ISGyP Companion Society Session at the 2020 USCAP Annual Meeting

Inflammatory myofibroblastic tumor of the uterus (uIMT) is rare. However, it has been increasingly recognized in recent years, largely due to more awareness of its occurrence in the gynecologic tract and the characterization of features that help distinguish it from more common lesions in the differential diagnosis, particularly smooth muscle neoplasms. One of these features is expression of anaplastic lymphoma kinase (ALK, also known as CD246), which has been documented in most uIMTs described in the literature. This review concentrates on the role of ALK testing in the diagnosis and management of uIMT. In terms of immunohistochemistry, an emphasis on antibody selection, sensitivity/specificity, interpretation and quality control is given. Regarding molecular analysis for ALK alterations, this review appraises fluorescence in situ hybridization and RNA sequencing technologies. Lastly, the role of tyrosine kinase inhibitor therapy in patients with uIMT is discussed, highlighting the importance of a correct diagnosis of this entity.

Mesenchymal Neoplasms of the Genitourinary System: A Selected Review with Recent Advances in Clinical, Diagnostic, and Molecular Findings

Mesenchymal neoplasms of the genitourinary (GU) tract often pose considerable diagnostic challenges due to their wide morphologic spectrum, relative rarity, and unexpected incidence at GU sites. Soft tissue tumors arise throughout the GU tract, whether from adventitia surrounding or connective tissues within the kidneys, urinary bladder, and male and female genital organs. This selected article focuses on a subset of these lesions, ranging from benign to malignant and encompassing a range of patterns of mesenchymal differentiation, where recent scholarship has lent greater insight into their clinical, molecular, or diagnostic features.

Inflammatory Myofibroblastic Tumor in Female Genital Tract

CONTEXT.—

Inflammatory myofibroblastic tumor is a mesenchymal neoplasm of low malignant potential. It was first described in lung, but is known to occur in many extrapulmonary sites including female genital organs, most commonly the uterus. It has a high recurrence rate and a low risk for metastasis. A more recently described aggressive variant, epithelioid myofibroblastic sarcoma with a predilection for the abdominal cavity of males, has also been recently reported to occur in the ovary. This tumor is composed of spindled and epithelioid myofibroblasts in a variably myxoid stroma and commonly shows a fascicular growth pattern with positive staining for desmin, smooth muscle actin, and CD10, which may mimic a smooth muscle or endometrial stromal neoplasm. In the female genital tract it has the potential for being misdiagnosed as a leiomyoma, endometrial stromal tumor, or as a myxoid leiomyosarcoma, resulting in undertreatment or overtreatment. It harbors rearrangements in the ALK gene, resulting in abnormal expression of ALK protein. Immunostaining for ALK is a helpful diagnostic tool.

OBJECTIVE.—

To provide a brief review of clinical, histologic, immunohistochemical, and molecular features of inflammatory myofibroblastic tumor with emphasis on possible diagnostic pitfalls in the female genital tract.

DATA SOURCES.—

Review of pertinent literature on inflammatory myofibroblastic tumor occurring in the female genital tract and personal experience of the authors.

CONCLUSIONS.—

Inflammatory myofibroblastic tumor in the female genital tract can mimic other more common benign and malignant tumors like leiomyoma, leiomyosarcoma, and endometrial stromal sarcoma. Familiarity with clinical and histologic features and use of ALK immunostaining can be critical for correct diagnosis.

Genomic heterogeneity of ALK fusion breakpoints in non-small-cell lung cancer

In lung adenocarcinoma, canonical EML4-ALK inversion results in a fusion protein with a constitutively active ALK kinase domain. Evidence of ALK rearrangement occurs in a minority (2-7%) of lung adenocarcinoma, and only ~60% of these patients will respond to targeted ALK inhibition by drugs such as crizotinib and ceritinib. Clinically, targeted anti-ALK therapy is often initiated based on evidence of an ALK genomic rearrangement detected by fluorescence in situ hybridization (FISH) of interphase cells in formalin-fixed, paraffin-embedded tissue sections. At the genomic level, however, ALK rearrangements are heterogeneous, with multiple potential breakpoints in EML4, and alternate fusion partners. Using next-generation sequencing of DNA and RNA together with ALK immunohistochemistry, we comprehensively characterized genomic breakpoints in 33 FISH-positive lung adenocarcinomas. Of these 33 cases, 29 (88%) had detectable DNA level ALK rearrangements involving EML4, KIF5B, or non-canonical partners including ASXL2, ATP6V1B1, PRKAR1A, and SPDYA. A subset of 12 cases had material available for RNA-Seq. Of these, eight of eight (100%) cases with DNA rearrangements showed ALK fusion transcripts from RNA-Seq; three of four cases (75%) without detectable DNA rearrangements were similarly negative by RNA-Seq, and one case was positive by RNA-Seq but negative by DNA next-generation sequencing. By immunohistochemistry, 17 of 19 (89%) tested cases were clearly positive for ALK protein expression; the remaining cases had no detectable DNA level rearrangement or had a non-canonical rearrangement not predicted to form a fusion protein. Survival analysis of patients treated with targeted ALK inhibitors demonstrates a significant difference in mean survival between patients with next-generation sequencing confirmed EML4-ALK rearrangements, and those without (20.6 months vs 5.4 months, P<0.01). Together, these data demonstrate abundant genomic heterogeneity among ALK-rearranged lung adenocarcinoma, which may account for differences in treatment response with targeted ALK inhibitors.

Assessment of EGFR mutation status in Tunisian patients with pulmonary adenocarcinoma

BACKGROUND

Despite recent advances, non-small cell lung cancer carries a grim prognosis. For appropriate treatment selection, the updated guidelines recommend broad molecular profiling for all patients with pulmonary adenocarcinoma. Precise histological subtyping and targeted epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) testing are mandatory.

METHODS

Herein, we assessed the EGFR mutation status of 26 formalin fixed-paraffin embedded (FFPE) samples of lung adenocarcinoma. Mutational analysis concerned exons 18-21 of EGFR by real-time polymerase chain reaction (Real time-PCR) using the Therascreen EGFR RGQ PCR mutation kit. ALK status was established on 22 among 26 patients using D5F3 antibody with a fully automated Ventana CDx technique.

RESULTS

Activating EGFR mutations were found in 3 men among 26 patients (11.5%). Positive ALK expression was found in 2 cases among 22 patients (9.09%).

CONCLUSION

Frequency of EGFR mutations in pulmonary adenocarcinomas of our series is similar to that found in the European ones with some particularities. The mutations detected are uncommon. Whereas, we found a high frequency of positive ALK expression in our series compared to frequency reported in literature. Further studies with larger Tunisian series are required to obtain more conclusive results.

Inflammatory myofibroblastic tumor of the uterus: a clinicopathological, immunohistochemical, and molecular analysis of 13 cases highlighting their broad morphologic spectrum

Inflammatory myofibroblastic tumors of the uterus are rare, and although most have a favorable prognosis, a small subset exhibit extrauterine disease, recur, or cause death. In this study, we evaluated the morphology and immunoprofile of 13 uterine inflammatory myofibroblastic tumors, including four with aggressive behavior. ALK rearrangements were detected by fluorescence in situ hybridization and fusion partners by anchored multiplex assay. Patients ranged from 8 to 63 (mean 39) years and tumors from 2.5 to 20 (mean 7.4) cm. Myxoid, compact, and hyalinized patterns were noted in 13, 12, and 2 tumors, ranging from 1 to 100%, 5 to 99%, and 0 to 5%, respectively. Nuclear atypia was mild in six (46%), moderate in five (38%), and severe in two (15%), with ganglion-like cells in two tumors. Mitoses ranged from 0 to 24 (mean 5) per 10 high-power fields. Inflammation was mild in five (38%), moderate in three (23%), and marked in five (38%), consisting of a lymphoplasmacytic infiltrate that was lymphocyte-predominant in six (46%). Lymphovascular invasion was noted in two (15%) and necrosis in eight (62%). All but one tumor were ALK-positive by immunohistochemistry, with granular cytoplasmic staining in nine (82%). ALK rearrangements (tested in 10) were detected in eight and was absent in one. The remaining tumor showed an isolated green 5' ALK signal. Fusion partners were identified in 10 (77%) and included THBS1 (n=3), IGFBP5 (n=2), DES (n=2), SEC31 (n=1), TPM3 (n=1), and TIMP3 (n=1). Size ≥8 cm was predictive of aggressive behavior (P<0.01), with increased mitoses (≥7 per 10 high-power fields), lymphovascular invasion, and compact-predominance approaching statistical significance. These data show that inflammatory myofibroblastic tumors of the uterus are morphologically heterogenous with frequent ALK expression and a variety of ALK fusion partners. Recognition of this rare mesenchymal neoplasm is crucial as those with aggressive behavior can potentially be treated with tyrosine kinase inhibitors.

ALK protein expression in pulmonary adenocarcinoma of Tunisian patients

BACKGROUND

It is now necessary to determine ALK status in order to use targeted therapy.

AIM

herein, we assess immunohistochemical profile of ALK protein in a series of Tunisian patients with pulmonary adenocarcinoma.

MATERIALS AND METHODS

ALK protein expression was studied applying the D5F3 antibody with a fully automated Ventana CDx technique on a series of 19 patients.

RESULTS

Positive ALK expression was found in one case (5.2%) corresponding to a papillary adenocarcinoma which showed a strong granular and homogenous cytoplasmic staining. The patient was a 30-years-old woman.

CONCLUSION

The frequency of positive ALK expression based on immunohistochemistry in our series was similar to that reported in the world literature.

From rabbit antibody repertoires to rabbit monoclonal antibodies

In this review, we explain why and how rabbit monoclonal antibodies have become outstanding reagents for laboratory research and increasingly for diagnostic and therapeutic applications. Starting with the unique ontogeny of rabbit B cells that affords highly distinctive antibody repertoires rich in in vivo pruned binders of high diversity, affinity and specificity, we describe the generation of rabbit monoclonal antibodies by hybridoma technology, phage display and alternative methods, along with an account of successful humanization strategies.

Next-generation sequencing facilitates detection of the classic E13-A20 EML4-ALK fusion in an ALK-FISH/IHC inconclusive biopsy of a stage IV lung cancer patient: a case report

BACKGROUND

Inhibition of the oncogenic fusion-gene EML4-ALK is a current first-line approach for patients with stage IV non-small cell lung cancer. While FISH was established as the gold standard for identifying these patients, there is accumulating evidence that other methods of detection, i.e., immunohistochemistry and next-generation sequencing (NGS), exist that may be equally successful. However, the concordance of these methods is under investigation.

CASE PRESENTATION

Adding to the current literature, we here report a 56 year old female never-smoker with stage IV lung adenocarcinoma whose biopsy was IHC and FISH inconclusive but positive in NGS. Retroactive profiling of the resection specimen corroborated fusion reads obtained by NGS, FISH-positivity and showed weak ALK-positivity by IHC. Consequently, we diagnosed the case as ALK-positive rendering the patient eligible to crizotinib treatment.

CONCLUSIONS

With IHC on biopsy material only, this case would have been overlooked withholding effective therapy.