ALK-positive histiocytosis: Report of a rare case with exclusive involvement of the central nervous system in an adult woman.

ALK-positive histiocytosis is a rare histiocytic disease characterized by ALK positivity. It was first described in 2008 as a systemic disease in infants. The disease often shows positivity for CD68 and CD163 on immunohistochemistry, and genomic analysis frequently reveals KIF5B::ALK fusions. ALK-positive histiocytosis typically follows an indolent course and has a promising prognosis, with conventional treatments usually being effective. Here, we report a rare case of ALK-positive histiocytosis with exclusive involvement of the central nervous system in a 33-year-old Asian adult woman. Although cranial MRI suggested a meningioma, immunohistochemical workup showed that the ALK-positive tumor cells expressed macrophage/histiocyte markers such as CD163 and CD68. Additionally, second-generation sequencing revealed a KIF5B::ALK fusion. Our case highlights the importance of the differential diagnosis in adult central nervous system tumors, emphasizing the combination of morphology, immunophenotype, and molecular approach with ALK status evaluation to confirm a diagnosis of ALK-positive histiocytosis. This case also expands the clinicopathologic spectrum of ALK-positive histiocytosis.

Incidentally Detected ALK-Positive Histiocytosis with EML4::ALK Fusion in a Solitary Pulmonary Nodule Following COVID-19 Infection: A Rare Case Report.

We hereby report a patient with ALK-positive histiocytosis with localized lung involvement. A 47-year-old woman presented with a solitary pulmonary nodule in the left upper lobe, 7 months after COVID infection. A well-defined 15 mm yellow mass was found in trisegmentectomy specimen. Histopathological examination revealed that the mass was composed of epithelioid and spindle cells with foamy cytoplasms. No necrosis, pleomorphism, or nuclear atypia was detected. The cells were positive for CD68, CD163, PU.1, ALK and negative for KRT, smooth muscle actin (SMA), S100, Melan-A, CD34, STAT6, and BRAF VE1. Flourescence in situ hybridization demonstrated ALK gene rearrangement, and next generation sequencing confirmed EML4::ALK fusion. Lung involvement in ALK-positive histiocytosis is characterized by the presence of pulmonary nodules, which can be seen in all forms of the disease. However, lung involvement is rarely seen in single-system ALK-positive histiocytosis. Our report represents the fourth documented instance of localized lung involvement in ALK-positive histiocytosis, an exceedingly rare occurrence, and it is the third instance with available molecular data.

New findings on the incidence and management of CNS adverse reactions in ALK-positive NSCLC with lorlatinib treatment.

To explore the presentation and control of CNS adverse reactions in patients with ALK-positive NSCLC treated with lorlatinib. This study includes a retrospective case report from Sir Run Run Shaw Hospital on a lorlatinib-treated patient with CNS adverse reactions and a systematic literature review of similar cases until January 2023. The report detailed a case of a 74-year-old male with Grade III CNS adverse reactions 25 days after starting lorlatinib, which were reversible with dose modification and pharmacotherapy. The review indicated a 19.39% occurrence rate of such reactions, with a 17% improvement rate post-dose adjustment. CNS adverse reactions frequently occur in ALK-positive NSCLC patients on lorlatinib, yet they are reversible with appropriate management. Research should continue to optimize treatment protocols to decrease these reactions' frequency.

Histiocytic neoplasms: a brief review and differential diagnosis.

Histiocytic neoplasms (HNs) include juvenile xanthogranuloma, Erdheim-Chester disease, Rosai-Dorfman disease, ALK-positive histiocytosis, and histiocytic sarcoma in the 5th edition of the World Health Organization Classification of Haematolymphoid Tumours. These entities are clinicopathologically distinctive, and typical histological findings have been established. However, the common feature of a proliferation of histiocytic cells often leads to morphological overlap among HNs, and also necessitates a differential diagnosis from several non-HNs or non-neoplastic conditions. In this review, we provide a brief summary of the clinical findings, molecular features, histopathologies, and immunophenotypes of HNs, as well as to discuss their differential diagnosis.

[ALK-positive anaplastic large cell lymphoma of paranasal sinuses: two cases report and literature review]. / ALK-pozitivnaya anaplasticheskaya krupnokletochnaya limfoma s porazheniem pridatochnykh pazukh nosa: dva klinicheskikh nablyudeniya i obzor literatury.

ALK-positive anaplastic large cell lymphoma is a rare T-cell lymphoma with ALK gene rearrangement that develops in children and young adults. The disease almost always affects the lymph nodes, and extranodal areas are also frequently involved. This article describes two cases of atypical localization of ALK-positive anaplastic large cell lymphoma with involvement of the paranasal sinuses.

Case report: Systemic presentation of ALK-positive Histiocytosis.

ALK-positive Histiocytosis (ALK-HSs) is a recently identified rare clinical entity characterized by tissue histiocytic alterations associated with ALK gene rearrangement. Clinical presentations can be solitary, multifocal, or systemic (involving multiple sites and organs). Due to limited reported cases, there is inadequate understanding of this disease. This report presents a case of ALK-HSs in a 71-year-old male patient who presented with hematuria for one week. Imaging studies conducted at an external hospital showed multiple lesions in the penis, bilateral testes, back skin, and the third lumbar vertebra. Histopathological findings included spindle and histiocytic cell proliferation with mild or indistinct cellular atypia, interstitial infiltration of lymphocytes, plasma cells, foamy histiocytes, and fibrous tissue proliferation. Immunohistochemistry of the lesion cells revealed positivity for CD68, CD163, ALK1, ALK (D5F3), and Vimentin. FISH testing indicated ALK gene separation in the lesion cells. NGS testing identified the fusion genes KIF5B(NM_004521) and ALK(NM_004304) in the lesion cells. We combined the characteristics of this case with a review of the literature to enhance our understanding of this rare clinical entity.

Bilateral optic neuropathy associated with lorlatinib monotherapy for ALK-positive metastatic lung adenocarcinoma.

Purpose: This report details the characteristics of a case of bilateral optic neuropathy during treatment with oral lorlatinib for ALK-positive metastatic adenocarcinoma of the lung. Observations: A 57-year-old woman with metastatic adenocarcinoma of the lung receiving treatment with lorlatinib presented to the ophthalmology urgent care with bilateral loss of vision that had progressed to no light perception over the previous 2 weeks. She was hospitalized for an extensive autoimmune, infectious, neoplastic, and paraneoplastic workup, which revealed enhancement of both optic nerves extending up to the optic chiasm and an area of restricted diffusion in the splenium of the corpus callosum on MRI. Lorlatinib was discontinued by her oncologist and she received treatment with five days of pulse-dose intravenous solumedrol as well as five days of plasmapheresis with gradual improvement in her vision. In follow-up, her vision had improved to 20/40 and 20/30. Conclusion and importance: There have been few reports describing vision loss associated with lorlatinib, an ALK/ROS1 targeted tyrosine kinase inhibitor used to treat metastatic lung adenocarcinoma. This report details the characteristics of a case of bilateral retrobulbar optic neuropathy as well as the treatment and recovery of such a case. Further exploration is needed in order to improve our understanding of the pathogenesis of this rare but potentially devastating adverse effect.

Localized anaplastic lymphoma kinase-positive histiocytosis in a cerebellar hemisphere with long-term treatment: illustrative case.

BACKGROUND: Anaplastic lymphoma kinase (ALK)-positive histiocytosis (ALK-H) is an emerging entity in the category of histiocytic neoplasms that was first reported as a multisystemic disease in three infants in 2008. The clinicopathological spectrum of ALK-H has been expanded to include localized disorders in specific organs, but the features of this subtype are not well known. The authors report a case of ALK-H localized in the central nervous system that was difficult to treat and review the relevant literature. OBSERVATIONS: The authors reviewed archival histiocytic tumors at their institute and found a pediatric case of ALK-H localized in a cerebellar hemisphere that had previously been reported as histiocytic sarcoma. Chemotherapy (approximately 1 year), additional surgery, and conventional chemotherapy (approximately 2.5 years) led to clinical remission, and maintenance chemotherapy was continued (approximately 1.5 years). Three years after completing treatment, a high-grade glioma was found in a cerebral hemisphere, and the patient died of the glioma 2 years later. LESSONS: Although the prognosis of ALK-H is generally good according to prior cases, the authors' case required long-term conventional chemotherapy, suggesting the tumor displayed aggressive characteristics. Early administration of ALK inhibitors may be necessary.

[Rare differential diagnosis of an osteolytic lesion of the mandible in a young adult]. / Seltene Differenzialdiagnose bei osteolytischer Läsion des Unterkiefers einer jungen Erwachsenen.

We report a rarely occurring hematologic neoplasm in a young adult. Hematologic neoplasms were first described in 2008 and are now included in both accepted tumor classification systems, i.e., International Consensus Classification and World Health Organization. This hematologic neoplasm shows a characteristic ALK positivity in immunohistochemical examination and correspondingly, ALK fusion genes in the molecular analysis. Pathologists should be aware of this entity, particularly as it is challenging to differentiate from other more frequent neoplasms of the same disease group or mesenchymal neoplasm with ALK aberration.

Podcast on Emerging Treatment Options for Pediatric Patients with ALK-Positive Anaplastic Large Cell Lymphoma and Inflammatory Myofibroblastic Tumors.

Anaplastic large cell lymphoma (ALCL) and inflammatory myofibroblastic tumor (IMT) are rare cancers observed predominantly in children and young adults. ALCL accounts for 10-15% of all pediatric non-Hodgkin lymphomas and is commonly diagnosed at an advanced stage of disease. In children, 84-91% of cases of ALCL harbor an anaplastic lymphoma kinase (ALK) gene translocation. IMT is a rare mesenchymal neoplasm that also tends to occur in children and adolescents. Approximately 50-70% of IMT cases involve rearrangements in the ALK gene. A combination of chemotherapeutic drugs is typically used for children with ALK-positive ALCL, and the only known curative therapy for ALK-positive IMT is complete surgical resection. Crizotinib, a first-generation ALK inhibitor, was approved in the USA in 2021 for pediatric patients and young adults with relapsed or refractory ALK-positive ALCL; however, its safety and efficacy have not been established in older adults. In 2022, crizotinib was approved for adult and pediatric patients with unresectable, recurrent, or refractory ALK-positive IMT. This podcast provides an overview of ALK-positive ALCL and IMT. We discuss the current treatment landscape, the role of ALK tyrosine kinase inhibitors, and areas of future research.

Anaplastic Large Cell Lymphoma (ALCL) With a Sarcomatoid Variant Presenting As Distributive Shock in a 41-Year-Old Female: A Case Report.

The sarcomatoid variant is considered a rare subtype of anaplastic large cell lymphoma. We present a 40-year-old diabetic female who was evaluated in the ER for distributive shock, requiring vasopressors and mechanical ventilation. An extensive workup was negative for infection. A serial CT scan of the abdomen and pelvis showed evolving lymphadenopathy, and a biopsy revealed malignant anaplastic lymphoma cells with a sarcomatous variant. The oncology team recommended the initiation of inpatient chemotherapy; however, the family opted to proceed with comfort care measures.

[Successful bridging therapy with alectinib prior to allogeneic stem cell transplantation for refractory ALK-positive anaplastic large cell lymphoma].

Although alectinib is effective for relapsed or refractory ALK-positive anaplastic large cell lymphoma (ALCL) and has a favorable safety profile, its role as a bridging therapy for allogeneic hematopoietic stem cell transplantation (allo-HSCT) and the role of allo-HSCT itself in this setting are unknown. A 35-year-old man with ALK-positive ALCL experienced relapse after first-line therapy with CHOP. Brentuximab vedotin led to partial response and high-dose chemotherapy combined with autologous HSCT was performed. However, disease progressed 15 months after transplantation, and alectinib was initiated. Complete response (CR) was achieved after three months of treatment, and alectinib was continued for 5 months. After cessation of alectinib, allogeneic bone marrow transplantation from an HLA 1-locus mismatched unrelated donor was performed after conditioning with fludarabine, busulfan, and total body irradiation. GVHD prophylaxis consisted of tacrolimus and short-term methotrexate. The post-transplant course was unremarkable except for grade I acute GVHD. The lymphoma has not recurred for 2 years after allo-HSCT without resuming alectinib. The clinical course of our case suggests that alectinib bridging therapy and allo-HSCT are effective in relapsed/refractory ALK-positive ALCL.

Imaging features of ALK-positive histiocytosis with neurological involvement: a case report and literature review.

Background: ALK-positive histiocytosis is an exceptionally rare neoplasm of histiocytes that predominantly involves the nervous system and can also affect the skin and other parts of the body. Previous relevant literature has provided limited information regarding the imaging manifestations of this disease with neurological involvement. Methods: We reported a case of ALK-positive histiocytosis with multisystem involvement. Together with a comprehensive literature review, the imaging characteristics of this disease in the nervous system were summarized. Results: A 3-year-old girl with abdominal pain and ambulation difficulty checked in at the Department of Pediatric Neurology. The initial diagnosis was "acute cerebellitis with ataxia" based on the elevated protein level in the cerebrospinal fluid (CSF). However, despite 3 months of treatment, her condition deteriorated. MRI showed an oval-shaped, intradural extramedullary nodule at the T6-T7 level. The patient was ultimately diagnosed as ALK-positive histiocytosis, accompanied by cauda equina and skin involvement. The literature review showed a total of 23 patients who had involvement of the nervous system and provided imaging descriptions. Together with our case, the imaging features were summarized as follows: iso-dense or slightly hyperdense on computed tomography (CT), isointense or iso-hypointense on T2-weighted imaging (T2WI), moderate homogeneous enhancement with mildly/markedly punctate enhancement or/and smooth ring enhancement on contrast-enhanced T1-weighted imaging (T1WI), restricted diffusion on diffuse weighted imaging (DWI), and elevated fluorodeoxyglucose (FDG) uptake on positron-emission tomography/computed tomography (PET/CT). Conclusion: The multimodal imaging findings of ALK-positive histiocytosis exhibit distinct characteristics, familiarity with which will enhance radiologists' expertise and facilitate accurate diagnosis of this disease.

Disseminated Anaplastic Lymphoma Kinase (ALK)-Positive T-cell Lymphoma Involving the Uterus and Cervix: A Case Report.

Primary or secondary non-Hodgkin lymphomas (NHLs) involving the female gynecologic tract are rare. T-cell subtypes are further rare and portend a worse prognosis. We present a case of a 23-year-old female presenting with a cervical mass accompanied by constitutional symptoms and abnormal vaginal bleeding. Immunohistochemistry studies revealed the presence of disseminated T-cell non-Hodgkin lymphoma that was anaplastic lymphoma kinase (ALK)-positive. The patient demonstrated a complete response to systemic chemotherapy initially and again after the relapse of the disease one year after diagnosis. To our knowledge, this is the first case of an ALK-positive T-cell lymphoma with secondary involvement of the uterus and cervix; all previously published cases of this histologic subtype in the gynecologic tract describe primary disease of the vagina. This case emphasizes the importance of immunohistochemistry studies inclusive of T-cell and B-cell markers when evaluating biopsies from cervical tumors to render the appropriate diagnosis and guide systemic therapy.

Alectinib continuation beyond progression in ALK-positive non-small cell lung cancer with alectinib-refractory.

Background: Alectinib, a next-generation anaplastic lymphoma kinase tyrosine kinase inhibitor (ALK-TKI), has demonstrated noteworthy efficacy in the treatment of non-small cell lung cancer (NSCLC). Unfortunately, 53.3% of untreated patients receiving first-line treatment with alectinib developed resistance to alectinib. However, despite the widespread use of alectinib, studies on the efficacy and safety of continuing alectinib with other necessary therapies after progression of alectinib and possible population of benefit are still limited. Methods: This retrospective cohort study included fifteen patients with ALK-positive NSCLC from nine institutions in China who experienced disease progression after first- or second-line treatment and continued to receive alectinib treatment between 2019 and 2022. This study aimed to evaluate the median progression-free survival (mPFS), objective response rate (ORR), median overall survival (mOS), and adverse events (AEs) of continuing alectinib combined with other therapies after the emergence of drug resistance. Results: Among fifteen patients eligible for this study, all patients started continuing treatment with alectinib after oligoprogression or central nervous system (CNS) progression. The mPFS for the whole cohort receiving continuing alectinib with other necessary therapies was 8 months [95% confidence interval (CI): 4 to not applicable (NA)], with an ORR of 46.7%. The mOS was not reached. During continuing alectinib treatment, only one patient experienced grade 2 elevation of aspartate aminotransferase (AST) and serum glutamic-oxaloacetic transaminase (SGOT). Conclusions: The continuation of alectinib treatment combined with other necessary therapies demonstrates favorable response and safety in patients with ALK-positive NSCLC who experienced oligoprogression or CNS progression following alectinib in first- or second-line therapy. Instead of immediately switching to another ALK-TKI, continuing alectinib combined with other necessary therapies may offer greater survival benefits to the patients.

Inflammation-related molecular signatures involved in the anticancer activities of brigatinib as well as the prognosis of EML4-ALK lung adenocarcinoma patient.

Although ALK tyrosine kinase inhibitors (ALK-TKIs) have shown remarkable benefits in EML4-ALK positive NSCLC patients compared to conventional chemotherapy, the optimal sequence of ALK-TKIs treatment remains unclear due to the emergence of primary and acquired resistance and the lack of potential prognostic biomarkers. In this study, we systematically explored the validity of sequential ALK inhibitors (alectinib, lorlatinib, crizotinib, ceritinib and brigatinib) for a heavy-treated patient with EML4-ALK fusion via developing an in vitro and in vivo drug testing system based on patient-derived models. Based on the patient-derived models and clinical responses of the patient, we found that crizotinib might inhibit proliferation of EML4-ALK positive tumors resistant to alectinib and lorlatinib. In addition, NSCLC patients harboring the G1269A mutation, which was identified in alectinib, lorlatinib and crizotinib-resistant NSCLC, showed responsiveness to brigatinib and ceritinib. Transcriptomic analysis revealed that brigatinib suppressed the activation of multiple inflammatory signaling pathways, potentially contributing to its anti-tumor activity. Moreover, we constructed a prognostic model based on the expression of IL6, CXCL1, and CXCL5, providing novel perspectives for predicting prognosis in EML4-ALK positive NSCLC patients. In summary, our results delineate clinical responses of sequential ALK-TKIs treatments and provide insights into the mechanisms underlying the superior effects of brigatinib in patients harboring ALKG1269A mutation and resistant towards alectinib, lorlatinib and crizotinib. The molecular signatures model based on the combination of IL6, CXCL1 and CXCL5 has the potential to predict prognosis of EML4-ALK positive NSCLC patients.

Case report: Clinical complete response in advanced ALK-positive lung squamous cell carcinoma: a case study of successful anti-PD-1 immunotherapy post ALK-TKIs failure.

In patients with advanced lung adenocarcinoma (LADC) harboring the echinoderm microtubule-associated protein-like 4 (EML4) -anaplastic lymphoma kinase (ALK) rearrangement, targeted therapy typically demonstrates superior efficacy as an initial treatment compared to chemotherapy. Following resistance to ALK-tyrosine kinase inhibitors (TKIs), regimens incorporating platinum-based dual agents or combined with bevacizumab often show effectiveness. However, therapeutic alternatives become constrained after resistance develops to both TKIs and platinum-based therapies. Given that the majority of ALK-positive non-small cell lung carcinomas (NSCLC) are LADC, the benefits of TKIs for patients with ALK-positive lung squamous cell carcinoma (LSCC) and the optimal treatment strategy for these patients remain a subject of debate. In this case study, we report on a patient with advanced LSCC, in whom the EML4-ALK rearrangement was identified via ARMS-PCR (Amplification Refractory Mutation System-Polymerase Chain Reaction). The patient underwent oral treatment with crizotinib and alectinib, showing effectiveness in both first-line and second-line ALK-TKI therapies, albeit with limited progression-free survival (PFS). Subsequent resistance to second-generation TKI was followed by the detection of tumors in the left neck region via computed tomography (CT). Biopsy pathology revealed non-squamous cell carcinoma, and subsequent treatment with platinum-based double-drug therapy proved ineffective. Further analysis through next-generation sequencing (NGS) indicated ALK negativity but a high expression of programmed death-ligand 1 (PD-L1). Immunotherapy was then initiated, resulting in a PFS of over 29 months and clinical complete remission (cCR). This case underscores the potential benefit of ALK-TKIs in patients with ALK-positive LSCC. Resistance to second-generation TKIs may lead to ALK negativity and histological transformation, highlighting the necessity of repeated biopsies post-TKI resistance for informed treatment decision-making. As of November 2023, imaging studies continue to indicate cCR in the patient, with a survival time exceeding 47 months.

Distinction of ALK fusion gene- and EGFR mutation-positive lung cancer with tumor markers.

BACKGROUND: It is difficult to predict gene mutations individually based on clinical background alone. Tumor markers may help to predict each gene mutation. Identifying tumor markers that can predict gene mutation will facilitate timely genetic testing and intervention. METHODS: We selected 134 cases of advanced or recurrent ALK-positive and 172 cases of advanced or recurrent EGFR-positive lung cancer from our clinical database. The cutoff values for the tumor markers were defined as 5.0 ng/mL or higher for carcinoembryonic antigen (CEA) and 3.5 ng/mL or higher for soluble fragment of cytokeratin 19 (CYFRA21-1) in accordance with the institutional standards. A positive CYFRA21-1:CEA ratio was defined as 0.7 or higher. RESULTS: The CEA-positivity rate was 49% for ALK-positive lung cancers and 73% for EGFR-positive lung cancers, which was significantly different (p < 0.001). The CYFRA21-1 positivity rate was significantly higher in ALK-positive lung cancer (36%) compared with EGFR-positive lung cancer (23%) (p = 0.034). The median CYFRA21-1:CEA ratio was 0.395 for the ALK group, which was significantly higher compared with 0.098 for the EGFR group (p < 0.001). These trends were similar when excluding histology other than adenocarcinoma. The median time-to-treatment failure (TTF) for initial tyrosine kinase inhibitor (TKI) therapy was 308 days for the high CYFRA21-1:CEA ratio group and 617 days for the low CYFRA21-1:CEA ratio group for ALK-positive lung cancer (p = 0.100). CONCLUSIONS: A higher proportion of patients with ALK-positive lung cancer were CYFRA21-1 positive and had higher CYFRA21-1:CEA ratios compared with EGFR-positive lung cancer patients.

Variant ALK-fusion positive anaplastic large cell lymphoma (ALCL): A population-based paediatric study of the NHL-BFM study group.

Frequency, distribution and prognostic meaning of ALK-partner genes other than NPM1 in ALK-positive anaplastic large-cell lymphoma (ALCL) are unknown. Forty-nine of 316 ALCL diagnosed in the NHL-BFM study group showed no nuclear ALK expression suggestive of a variant ALK-partner; 41 were analysed by genomic capture high-throughput sequencing or specific RT-PCRs. NPM1::ALK was detected in 13 cases. Among the 28 patients with a non-NPM1::ALK-fusion partner, ATIC (n = 8; 29%) and TPM3 (n = 9; 32%) were the most common. Five of eight patients with ATIC::ALK-positive ALCL relapsed, none of nine with TPM3::ALK. Variant ALK-partners are rare and potentially associated with different prognoses.