Lipofibromatosis-like neural tumor

Last updated
Lipofibromatosis-like neural tumor
Specialty Pediatric or adult dermatology and surgery
Usual onsetChildren and young adults aged <1 to 38 years
CausesAn NTRK1- containing fusion gene in ~80% of cases
Treatment Surgical resection of the tumor
Prognosis Good
FrequencyVery rare

Lipofibromatosis-like neural tumor (LPF-NT) is an extremely rare soft tissue tumor first described by Agaram et al in 2016. [1] As of mid-2021, at least 39 cases of LPF-NT have been reported in the literature. [2] [3] [4] [5] LPF-NT tumors have several features that resemble lipofibromatosis (LPF) tumors, [6] malignant peripheral nerve sheath tumors, spindle cell sarcomas, [3] low-grade neural tumors, peripheral nerve sheath tumors, and other less clearly defined tumors; [1] Prior to the Agaram at al report, LPF-NTs were likely diagnosed as variants or atypical forms of these tumors. The analyses of Agaram at al and subsequent studies [4] uncovered critical differences between LPF-NT and the other tumor forms which suggest that it is a distinct tumor entity differing not only from lipofibromatosis but also the other tumor forms. [7]

Contents

LPF-NTs are locally invasive, are commonly treated by surgical excision, and have a relatively high rate of local recurrence if their surgical excisions are incomplete. [8] They are generally considered to be benign, non-metastasizing (i.e. not spreading to other parts of the body) tumors. [6] [8] However, one case of LFT-NT reported by Agaram et al was associated with metastasis, apparently as a result of the tumor's cells transformation into a malignant sarcoma. Further studies are needed to determine the frequency of such cases and the overall metastatic potential of LPF-NT. [1]

LPF-NTs were given the "neural tumor" terminology because in at least some cases: 1) their tumor cells express S100 and CD34 but not SOX10 proteins, a pattern that is often found in neural [7] and neuroectodermal tumor cells; [1] and 2) their histopathology consists of tumor cell infiltrations into adipose tissues in a pattern that is very similar to that found in some low grade malignant peripheral nerve sheath tumors. [1]

Presentation

Lipofibromatosis-like neural tumors have been reported in the English literature to develop in children and young adults aged from 2 to 38 years (median age ~17 years). [1] However, a recent study in the Chinese literature reported on three cases in infants <1 year old. [5] LPF-NTs have almost always been superficially situated and occurring primarily in the legs and arms with fewer cases in the head, neck, and trunk areas. [1] Three cases of primary and one case of recurrent LPF-NT tumors presented with infiltration into the adjacent skeletal muscles [1] and one recently reported case presented with the tumor situated in, and limited to, the lumbar spine. [3] The tumors have ranged from 1.3 cm [1] to 8.7 cm [3] in maximum diameter; may be tender [4] but usually are painless (although the lumbar spine tumor presented with intermittent abdominal pain [3] ); and may be pigmented. [4] [6] In as high as 30% of cases, patients treated with surgical removal of the LPF-NT have presented with recurrent tumors at the site of surgery. The recurrent tumors have, in general, showed similar features to the primary tumors. In particular, they almost always continue to act in a non-malignant manner. [8]

Pathology

Histpathologically, hemotoxin and eosin dye-stained and otherwise properly prepared LPF-NT tissues consist of mildly to moderately atypical spindle-shaped cells that variably infiltrate into subcutaneous adipose (i.e. fat) tissues. [8] The spindle-shaped cells commonly have indistinct nucleoli borders (nucleoli are the largest structures in a cell's nucleus), hyperchromasia (i.e. nuclei that are denser than normal), pale to slightly eosinophilic (i.e. taking up more eosin dye than normal) cytoplasm, and a low rate of cell division as determined by mitotic index analysis. Cases showing tissue necrosis (i.e. foci of dead or dying cells) are rare. The spindle-shaped cells espress S100 and CD34 marker proteins in a variable proportion of cases. [2] One study found that the cells in five of five LDF-NTs overexpress, i.e. contain increased numbers of, one or more of the three Trk receptors (i.e. TrkA, TrkB, and TrkC) as judged using a pan-TRK immunohistochemistry assay. This assay uses a Pan-Trk antibody, i.e. an antibody that binds with and thereby enables the enumeration of all three Trk proteins. [9] Other studies have found that this finding in LPF-NTs is due to overexpression of the TrkA receptor. Tumor tissues that have a histopathology compatible with LPF-NT plus spindle-shaped cells that express D34 and S100 but not SOX10 marker proteins are almost certainly LPF-NTs. [4]

Gene abnormalities

LPF-NT spindle-shaped cells usually express fusion genes which contain a portion of the NTRK1 gene which codes for (i.e. is responsible for producing) the TrkA receptor protein. Fusion genes are abnormal and potentially tumor-inducing genes formed by mergers between parts of two different genes that form as a result of chromosomal translocations, interstitial deletions, or inversions. The NTRK1 gene is located at bands 21 to 22 on the long (i.e "q") arm of chromosome 1. The most often observed NTRK1 fusion gene in LPF-NTs contains a part of NTRK1 fused with a part of the LMNA (i.e. lamin A/C) gene normally located close to the NTRK1 gene at band 22 on the q arm of chromosome 1. [10] Other genes with which NTRK1 has been found to fuse with in LPF-NT are parts of: the TPR (i.e. translocated promoter region, nuclear basket protein) gene located at band 31.1 on the q arm of chromosome 1 [11] and the TPM3 (i.e. tropomyosin 3 ) gene located at band 21.3 on the q arm of chromosome 1. [8] [12] All three of these fusion genes result from interstitial deletions of the genetic material between a part of the NTRK1 gene and a part of the cited genes on chromosome 1. [13] In studies of LPF-NT tumors on small numbers of individuals, NTRK1-containing fusion genes were detected in 71%, i.e. 10 of 14 individuals, [1] 80%, i.e. 4 of 5 individuals, [8] and 100%, i.e. 5 of 5 individuals [9] with LPF-NT. Individuals diagnosed with non-neural lipofibromatosis have not been reported to harbor NTRK1-containing fusion genes. [6]

The protein products (termed fusion proteins or chimeric proteins) of the three NTRK1-containing fusion genes possess overactive and unregulated TrkA, i.e. tropomyosin receptor kinase A, activity that stimulates the PI3K/AKT/mTOR, MAPK/ERK, and PLCG1 cell signaling pathways. Each of these pathways are known to promote the development and/or progression of a large variety of benign and malignant tumors. [1] Studies have suggested that one or more of these pathways may drive LPF-NT. [1] [8] [12]

Diagnosis

The diagnosis of LPF-NT rests upon a combination of factors none of which by themselves are definitive. These factors are its clinical presentation, histopathology including the presence of tumor cells expressing S100 and CD34 but not SOX10 marker proteins, and tumor cell expression of a fusion gene containing part of the NTRK1 gene. [1] [4] LPF-NT has been difficult to distinguish from other oval-shaped/spindle-shaped fibroplast tumors that arise in the superficial soft tissue of young individuals such as lipofibromatosis (the presence of a NTRK1 fusion gene indicates the tumor is an LPF-NT) [6] and fibroma, infantile fibromatosis, congenital fibrosarcoma, solitary fibrous tumor, and dermatofibrosarcoma protuberans (broad expression of the CD34 and/or S100 marker protein strongly supports the diagnosis of LPF-NT [8] ).

Treatment

LPF-NTs are commonly treated by surgical resection. [2] [3] [8] [14] In up to 30% of these resections, the tumor recurs at the surgical site [8] apparently because the resections did not remove all of the tumor. [2] Recurrences of the tumor have been successfully treated by repeated resections. [8] However, there one reported case and it is expected that there will be future case of LPF-NT that because of their tumors' location, size, or aggressiveness, require alternatives or adjuvants to surgical resection. [3] The authors of many studies have suggested that one promising alternative and/or adjuvant to surgical treatment of LPF-NTs is to inhibit the action of the NTRK1 gene's product, TrkA. [1] [2] [6] [8] [12] [13] [14]

As indicated in the above section on gene abnormalities, about 80% (19 of 24 cases) of LPF-NTs contain NTRK1-containing fusion genes that produce abnormally high levels of overactive and uncontrolled tropomyosin receptor kinase A activity which may promote the development and/or progression of LPF-NTs. Two inhibitors of receptor tyrosine kinase activity, larotrectinib and entrectinib, have been shown to be effective in phase I (screening for safety) and phase II (assessing dosage requirements and efficacy) clinical trials in patients with various types of Trk fusion gene-positive tumors although not in LPF-NTs. [15] [16] In 2018, the Food and Drug Administration approved larotrectinib for adult and pediatric patients with solid tumors that: 1) have an NTRK-containing fusion gene that is not resistant to the drug; 2) are metastatic or surgically inaccessible; 3) have no satisfactory alternative treatment; or 4) have progressed after treatment. [2] In 2020, a young adult presented with a spinal LPF-NT that, because of its size and location, was deemed surgically unresectable. The patient was treated in a clinical trial with entrectinib. The treatment reduced the tumor's size by 45% within 20 weeks at which time it was removed surgically and found to consist of 95% necrotic cells. While further clinical trials on many more individuals are needed, Tka-inhibitors may have a role as adjuvants to surgery or in various severe cases as the main treatment of LPF-NTs. [3]

Related Research Articles

<span class="mw-page-title-main">Nodular fasciitis</span> Medical condition

Nodular fasciitis (NF) is a benign, soft tissue tumor composed of myofibroblasts that typically occurs in subcutaneous tissue, fascia, and/or muscles. The literature sometimes titles rare NF variants according to their tissue locations. The most frequently used and important of these are cranial fasciitis and intravascular fasciitis. In 2020, the World Health Organization classified nodular fasciitis as in the category of benign fibroblastic/myofibroblastic tumors. NF is the most common of the benign fibroblastic proliferative tumors of soft tissue.

Trk receptors are a family of tyrosine kinases that regulates synaptic strength and plasticity in the mammalian nervous system. Trk receptors affect neuronal survival and differentiation through several signaling cascades. However, the activation of these receptors also has significant effects on functional properties of neurons.

Giant cell fibroblastoma (GCF) is a rare type of soft-tissue tumor marked by painless nodules in the dermis and subcutaneous tissue. These tumors may come back after surgery, but they do not spread to other parts of the body. They occur mostly in boys. GCF tumor tissues consist of bland spindle-shaped or stellate-shaped cells interspersed among multinucleated giant cells.

Infantile digital fibromatosis (IDF), also termed inclusion body fibromatosis, Reye tumor, or Reye's tumor, usually occurs as a single, small, asymptomatic, nodule in the dermis on a finger or toe of infants and young children. IMF is a rare disorder with approximately 200 cases reported in the medical literature as of 2021. The World Health Organization in 2020 classified these nodules as a specific benign tumor type in the category of fibroblastic and myofibroblastic tumors. IDF was first described by the Australian pathologist, Douglas Reye, in 1965.

Fibrous hamartoma of infancy (FHI) is a rare, typically painless, benign tumor that develops in the subcutaneous tissues of the axilla, arms, external genitalia, or, less commonly, various other areas. It is diagnosed in children who are usually less than 2 years old or, in up to 20% of cases, develops in utero and is diagnosed in an infant at birth.

Infantile myofibromatosis (IMF) is a rare tumor found in 1 in 150,000 to 1 in 400,000 live births. It is nonetheless the most common tumor derived from fibrous connective tissue that occurs primarily in infants and young children. IMF tumors are benign in the sense that they do not metastasize to distant tissues although when occurring in the viscera, i.e. internal organs, carry guarded to poor prognoses and can be life-threatening, particularly in newborns and young infants. The condition was first described by Arthur Purdy Stout as congenital generalized fibromatosis – in which he coined the word fibromatosis – in 1954.

Extraskeletal myxoid chondrosarcoma (EMC) is a rare low-grade malignant mesenchymal neoplasm of the soft tissues, that differs from other sarcomas by unique histology and characteristic chromosomal translocations. There is an uncertain differentiation and neuroendocrine differentiation is even possible.

Porocarcinoma (PCA) is a rare form of skin cancer that develops in eccrine sweat glands, i.e. the body's widely distributed major type of sweat glands, as opposed to the apocrine sweat glands which are located primarily in the armpits and perineal area. This cancer typically develops in individuals as a single cutaneous tumor in the intraepidermal spiral part of these sweat glands' ducts at or near to where they open on the skin's surface. PCA tumors are classified as one form of the cutaneous adnexal tumors; in a study of 2,205 cases, PCA was the most common (11.8%) form of these tumors.

ETV6-NTRK3 gene fusion is the translocation of genetic material between the ETV6 gene located on the short arm of chromosome 12 at position p13.2 and the NTRK3 gene located on the long arm of chromosome 15 at position q25.3 to create the (12;15)(p13;q25) fusion gene, ETV6-NTRK3. This new gene consists of the 5' end of ETV6 fused to the 3' end of NTRK3. ETV6-NTRK3 therefore codes for a chimeric oncoprotein consisting of the helix-loop-helix (HLH) protein dimerization domain of the ETV6 protein fused to the tyrosine kinase domain of the NTRK3 protein. The ETV6 gene codes for the transcription factor protein, ETV6, which suppresses the expression of, and thereby regulates, various genes that in mice are required for normal hematopoiesis as well as the development and maintenance of the vascular network. NTRK3 codes for Tropomyosin receptor kinase C a NT-3 growth factor receptor cell surface protein that when bound to its growth factor ligand, neurotrophin-3, becomes an active tyrosine kinase that phosphorylates tyrosine residues on, and thereby stimulates, signaling proteins that promote the growth, survival, and proliferation of their parent cells. The tyrosine kinase of the ETV6-NTRK3 fusion protein is dysfunctional in that it is continuously active in phosphorylating tyrosine residues on, and thereby continuously stimulating, proteins that promote the growth, survival, and proliferation of their parent cells. In consequence, these cells take on malignant characteristics and are on the pathway of becoming cancerous. Indeed, the ETV6-NTRK3 fusion gene appears to be a critical driver of several types of cancers. It was originally identified in congenital fibrosarcoma and subsequently found in mammary secretory carcinoma, mammary analogue secretory carcinoma of salivary glands, salivary gland–type carcinoma of the thyroid, secretory carcinoma of the skin, congenital fibrosarcoma, congenital mesoblastic nephroma, rare cases of acute myelogenous leukemia, ALK-negative Inflammatory myofibroblastic tumour, cholangiocarcinoma, and radiation-induced papillary thyroid carcinoma.

<span class="mw-page-title-main">Low-grade fibromyxoid sarcoma</span> Medical condition

Low-grade fibromyxoid sarcoma (LGFMS) is a rare type of low-grade sarcoma first described by H. L. Evans in 1987. LGFMS are soft tissue tumors of the mesenchyme-derived connective tissues; on microscopic examination, they are found to be composed of spindle-shaped cells that resemble fibroblasts. These fibroblastic, spindle-shaped cells are neoplastic cells that in most cases of LGFMS express fusion genes, i.e. genes composed of parts of two different genes that form as a result of mutations. The World Health Organization (2020) classified LGFMS as a specific type of tumor in the category of malignant fibroblastic and myofibroblastic tumors.

<span class="mw-page-title-main">Mammary-type myofibroblastoma</span> Medical condition

Mammary-type myofibroblastoma (MFB), also named mammary and extramammary myofibroblastoma, was first termed myofibrolastoma of the breast, or, more simply, either mammary myofibroblastoma (MMFB) or just myofibroblastoma. The change in this terminology occurred because the initial 1987 study and many subsequent studies found this tumor only in breast tissue. However, a 2001 study followed by numerous reports found tumors with the microscopic histopathology and other key features of mammary MFB in a wide range of organs and tissues. Further complicating the issue, early studies on MFB classified it as one of various types of spindle cell tumors that, except for MFB, were ill-defined. These other tumors, which have often been named interchangeably in different reports, are: myelofibroblastoma, benign spindle cell tumor, fibroma, spindle cell lipoma, myogenic stromal tumor, and solitary stromal tumor. Finally, studies suggest that spindle cell lipoma and cellular angiofibroma are variants of MFB. Here, the latter two tumors are tentatively classified as MFB variants but otherwise MFB is described as it is more strictly defined in most recent publications. The World Health Organization in 2020 classified mammary type myofibroblastoma tumors and myofibroblastoma tumors as separate tumor forms within the category of fibroblastic and myofibroblastic tumors.

Mammary analogue secretory carcinoma (MASC), also termed MASCSG, is a salivary gland neoplasm. It is a secretory carcinoma which shares the microscopic pathologic features with other types of secretory carcinomas including mammary secretory carcinoma, secretory carcinoma of the skin, and salivary gland–type carcinoma of the thyroid. MASCSG was first described by Skálová et al. in 2010. The authors of this report found a chromosome translocation in certain salivary gland tumors, i.e. a (12;15)(p13;q25) fusion gene mutation. The other secretory carcinoma types carry this fusion gene.

Acral myxoinflammatory fibroblastic sarcoma (AMSF), also termed myxoinflammatory fibroblastic sarcoma (MSF), is a rare, low-grade, soft tissue tumor that the World Health Organization (2020) classified as in the category of rarely metastasizing fibroblastic and myofibroblastic tumors. It is a locally aggressive neoplasm that often recurs at the site of its surgical removal. However, it usually grows slowly and in only 1–2% of cases spreads to distant tissues.

<span class="mw-page-title-main">Proliferative fasciitis and proliferative myositis</span> Medical condition

Proliferative fasciitis and proliferative myositis (PF/PM) are rare benign soft tissue lesions that increase in size over several weeks and often regress over the ensuing 1–3 months. The lesions in PF/PM are typically obvious tumors or swellings. Historically, many studies had grouped the two descriptive forms of PF/PM as similar disorders with the exception that proliferative fasciitis occurs in subcutaneous tissues while proliferative myositis occurs in muscle tissues. In 2020, the World Health Organization agreed with this view and defined these lesions as virtually identical disorders termed proliferative fasciitis/proliferative myositis or proliferative fasciitis and proliferative myositis. The Organization also classified them as one of the various forms of the fibroblastic and myofibroblastic tumors.

Lipofibromatosis (LPF) is an extremely rare soft tissue tumor which was first clearly described in 2000 by Fetsch et al as a strictly pediatric, locally invasive, and often recurrent tumor. It is nonetheless a non-metastasizing, i.e. benign, tumor. While even the more recent literature has sometimes regarded LPF as a strictly childhood disorder, rare cases of LPF has been diagnosed in adults. The diagnosis of lipofibromatosis should not be automatically discarded because of an individual's age.

Cellular angiofibroma (CAF) is a rare, benign tumor of superficial soft tissues that was first described by M. R. Nucci et al. in 1997. These tumors occur predominantly in the distal parts of the female and male reproductive systems, i.e. in the vulva-vaginal and inguinal-scrotal areas, respectively, or, less commonly, in various other superficial soft tissue areas throughout the body. CAF tumors develop exclusively in adults who typically are more than 30 years old.

Angiofibroma of soft tissue (AFST), also termed angiofibroma, not otherwise specified, is a recently recognized and rare disorder that was classified in the category of benign fibroblastic and myofibroblastic tumors by the World Health Organization in 2020. An AFST tumor is a neoplasm that was first described by A. Mariño-Enríquez and C.D. Fletcher in 2012.

Dermatofibrosarcoma protuberans, fibrosarcomatous (DFSP-FS), also termed fibrosarcomatous dermatofibrosarcoma protuberans, is a rare type of tumor located in the dermis. DFSP-FS tumors have been viewed as: 1) a more aggressive form of the dermatofibrosarcoma protuberans (DFSP) tumors because they have areas that resemble and tend to behave like malignant fibrosarcomas or 2) as a distinctly different tumor than DFSP. DFSP-FS tumors are related to DFSP. For example, surgically removed DFSP tumors often recur with newly developed fibrobosarcoma-like areas. Nonetheless, the World Health Organization (WHO), 2020, classified DFSP and DFSP-FS as different tumors with DFSP being in the category of benign and DFSP-FS in the category of rarely metastasizing fibroblastic and myofibroblastic tumors. This article follows the WHO classification: the 5-15% of DFSP tumors that have any areas of fibrosarcomatous microscopic histopathology are here considered DFSP-FS rather than DFSP tumors.

Gardner fibroma (GF) is a benign fibroblastic tumor. GF tumors typically develop in the dermis and adjacent subcutaneous tissue lying just below the dermis. These tumors typically occur on the back, abdomen, and other superficial sites but in rare cases have been diagnoses in internal sites such as the retroperitoneum and around the large blood vessels in the upper thoracic cavity. The World Health Organization, 2020, classified Gardner fibroma as a benign tumor in the category of fibroblastic and myofibroblastic tumors.

Low-grade myofibroblastic sarcoma (LGMS) is a subtype of the malignant sarcomas. As it is currently recognized, LGMS was first described as a rare, atypical myofibroblastic tumor by Mentzel et al. in 1998. Myofibroblastic sarcomas had been divided into low-grade myofibroblastic sarcomas, intermediate‐grade myofibroblasic sarcomas, i.e. IGMS, and high‐grade myofibroblasic sarcomas, i.e. HGMS based on their microscopic morphological, immunophenotypic, and malignancy features. LGMS and IGMS are now classified together by the World Health Organization (WHO), 2020, in the category of intermediate fibroblastic and myofibroblastic tumors. WHO, 2020, classifies HGMS as a soft tissue tumor in the category of tumors of uncertain differentiation. This article follows the WHO classification: here, LGMS includes IGMS but not HGMS which is a more aggressive and metastasizing tumor than LGMS and consists of cells of uncertain origin.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Agaram NP, Zhang L, Sung YS, Chen CL, Chung CT, Antonescu CR, Fletcher CD (October 2016). "Recurrent NTRK1 Gene Fusions Define a Novel Subset of Locally Aggressive Lipofibromatosis-like Neural Tumors". The American Journal of Surgical Pathology. 40 (10): 1407–16. doi:10.1097/PAS.0000000000000675. PMC   5023452 . PMID   27259011.
  2. 1 2 3 4 5 6 Crumbach L, Descotes F, Bringuier PP, Poulalhon N, Balme B, Juliet T, Lopez J, Harou O (November 2020). "Lipofibromatosis-Like Neural Tumor: A Case Report and Review of the Literature". The American Journal of Dermatopathology. 42 (11): 881–884. doi:10.1097/DAD.0000000000001734. PMID   32618702. S2CID   220327572.
  3. 1 2 3 4 5 6 7 8 Dupuis M, Shen Y, Curcio C, Meis JM, Wang WL, Amini B, Rhines L, Reuther J, Roy A, Fisher KE, Conley AP, Andrew Livingston J (2020). "Successful treatment of lipofibromatosis-like neural tumor of the lumbar spine with an NTRK-fusion inhibitor". Clinical Sarcoma Research. 10: 14. doi: 10.1186/s13569-020-00136-6 . PMC   7412810 . PMID   32782782.
  4. 1 2 3 4 5 6 Panse G, Reisenbichler E, Snuderl M, Wang WL, Laskin W, Jour G (February 2021). "LMNA-NTRK1 rearranged mesenchymal tumor (lipofibromatosis-like neural tumor) mimicking pigmented dermatofibrosarcoma protuberans". Journal of Cutaneous Pathology. 48 (2): 290–294. doi:10.1111/cup.13772. PMID   32519338. S2CID   219562066.
  5. 1 2 Wang H, Chen L (December 2020). "[Clinicopathological and molecular genetic features of lipofibromatosis-like neural tumor]". Zhonghua Bing Li Xue Za Zhi = Chinese Journal of Pathology (in Chinese). 49 (12): 1272–1275. doi:10.3760/cma.j.cn112151-20200319-00231. PMID   33287512.
  6. 1 2 3 4 5 6 Malik F, Santiago T, Newman S, McCarville B, Pappo AS, Clay MR (June 2020). "An addition to the evolving spectrum of lipofibromatosis and lipofibromatosis-like neural tumor: Molecular findings in an unusual phenotype aid in accurate classification". Pathology, Research and Practice. 216 (6): 152942. doi:10.1016/j.prp.2020.152942. PMID   32299759. S2CID   215803522.
  7. 1 2 Suurmeijer AJ, Dickson BC, Swanson D, Zhang L, Sung YS, Cotzia P, Fletcher CD, Antonescu CR (December 2018). "A novel group of spindle cell tumors defined by S100 and CD34 co-expression shows recurrent fusions involving RAF1, BRAF, and NTRK1/2 genes". Genes, Chromosomes & Cancer. 57 (12): 611–621. doi:10.1002/gcc.22671. PMC   6746236 . PMID   30276917.
  8. 1 2 3 4 5 6 7 8 9 10 11 12 Lao IW, Sun M, Zhao M, Yu L, Wang J (August 2018). "Lipofibromatosis-like neural tumour: a clinicopathological study of ten additional cases of an emerging novel entity". Pathology. 50 (5): 519–523. doi:10.1016/j.pathol.2018.03.007. PMID   29958731. S2CID   49615346.
  9. 1 2 Hung YP, Fletcher CD, Hornick JL (October 2018). "Evaluation of pan-TRK immunohistochemistry in infantile fibrosarcoma, lipofibromatosis-like neural tumour and histological mimics". Histopathology. 73 (4): 634–644. doi:10.1111/his.13666. PMID   29863809. S2CID   44131360.
  10. "LMNA lamin A/C [Homo sapiens (Human)] - Gene - NCBI".
  11. "TPR translocated promoter region, nuclear basket protein [Homo sapiens (Human)] - Gene - NCBI".
  12. 1 2 3 Rekhi B, Shetty O, Bapat P, Gurav M, Qureshi S (February 2021). "A Case of Inv(1)(q23q31) TPR-NTRK1 Fusion-Positive Spindle Cell Neoplasm in an Infant-Uncovered by Next-Generation Sequencing: Diagnostic Challenge, Review, and Therapeutic Implications". International Journal of Surgical Pathology. 29 (1): 102–108. doi:10.1177/1066896920927467. PMID   32489127. S2CID   219284010.
  13. 1 2 Parham DM (2018). "Fibroblastic and myofibroblastic tumors of children: new genetic entities and new ancillary testing". F1000Research. 7: 1963. doi: 10.12688/f1000research.16236.1 . PMC   6305242 . PMID   30613391.
  14. 1 2 Al-Ibraheemi A, Folpe AL, Perez-Atayde AR, Perry K, Hofvander J, Arbajian E, Magnusson L, Nilsson J, Mertens F (March 2019). "Aberrant receptor tyrosine kinase signaling in lipofibromatosis: a clinicopathological and molecular genetic study of 20 cases". Modern Pathology. 32 (3): 423–434. doi: 10.1038/s41379-018-0150-3 . PMID   30310176. S2CID   52962101.
  15. Kojadinovic A, Laderian B, Mundi PS (August 2021). "Targeting TRK: A fast-tracked application of precision oncology and future directions". Critical Reviews in Oncology/Hematology. 165: 103451. doi:10.1016/j.critrevonc.2021.103451. PMID   34389458.
  16. Han SY (June 2021). "TRK Inhibitors: Tissue-Agnostic Anti-Cancer Drugs". Pharmaceuticals (Basel, Switzerland). 14 (7): 632. doi: 10.3390/ph14070632 . PMC   8308490 . PMID   34209967.