Figure - available from: Case Reports in Otolaryngology
This content is subject to copyright. Terms and conditions apply.
Acellular material accumulation with homogeneous eosinophilic appearance called “amianthoid fibers” (HE, 100x).
Source publication
Intranodal palisaded myofibroblastoma (IPM), also known as “intranodal hemorrhagic spindle cell tumor with amianthoid fibers,” is a rare benign mesenchymal tumor originating from smooth muscle cells and myofibroblasts, often with the presence of amianthoid fibers. Usually IPM affects inguinal lymph nodes, but three cases have been described in the...
Citations
... Upon microscopy, the neoplasm Spindle shaped cells constituting intranodal palisaded myofibroblastoma appear immune reactive to smooth muscle actin (SMA), vimentin, cyclin D1 or factor XIIIa. The amianthoid fibres may be highlighted with elastic stains, trichrome stain or smooth muscle actin (SMA) wherein type I collagen fibres appear confined to centric fibres and type III collagen fibres appear confined to periphery of amianthoid fibres [5,6]. ...
... Intranodal palisaded myofibroblastoma is immune nonreactive to S100 protein, synaptophysin, glial fibrillary acidic protein (GFAP), CD34, human melanoma black 45(HMB45) antigen, desmin, keratin and epithelial membrane antigen (EMA). Ki67 proliferative index is <5% [6,7]. Intranodal palisaded myofibroblastoma requires segregation from neoplasms as benign metastasizing leiomyoma, schwannoma, leiomyosarcoma, malignant melanoma, follicular dendritic cell sarcoma, Kaposi's sarcoma, diverse carcinomas or sarcomas metastatic to regional lymph nodes, spindle cell carcinoma or spindle cell variant of malignant melanoma with metastasis into regional lymph nodes [6,7]. ...
... Ki67 proliferative index is <5% [6,7]. Intranodal palisaded myofibroblastoma requires segregation from neoplasms as benign metastasizing leiomyoma, schwannoma, leiomyosarcoma, malignant melanoma, follicular dendritic cell sarcoma, Kaposi's sarcoma, diverse carcinomas or sarcomas metastatic to regional lymph nodes, spindle cell carcinoma or spindle cell variant of malignant melanoma with metastasis into regional lymph nodes [6,7]. Intranodal palisaded myofibroblastoma can be appropriately alleviated with simple or localized surgical eradication of the neoplasm. ...
... IPM is a relatively rare intranodal mesenchymal tumor of smooth muscle fibers or myofibroblasts, typically presenting in the inguinal nodes and infrequently at other sites such as cervical [6], submandibular [7,8], supraclavicular [9], axillary [10], mediastinal [11], and retroperitoneal nodes [12]. Although mostly seen in middle-age, IPM can affect a broad age group (19-71 years) [10], with a single case reported in an infant [13]. ...
Patient: Male, 48-year-old
Final Diagnosis: Intranodal palisaded myofibroblastoma
Symptoms: Inguinal lump
Medication: —
Clinical Procedure: Lumpectomy
Specialty: Pathology • Surgery
Objective
Rare disease
Background
Benign tumors of the lymph nodes are rare and are not usually considered in the differential diagnosis in cases of lymphadenopathy because reactive hyperplasia, lymphoma, and metastatic carcinoma are the most likely causes of enlarged nodes. Intranodal palisaded myofibroblastoma (IPM) is a very rare benign mesenchymal tumor of the lymph nodes most often affecting but not limited to the inguinal region, with up to 92 cases reported in the English literature. The cell of origin is the intranodal differentiated smooth muscle cell or myofibroblast. Although the pathophysiology of IPM remains unclear, theories about viral oncogenesis and mutational changes in the β-catenin gene with subsequent abnormal expression of β-catenin and cyclin D1 have been raised.
Case Report
We report a case of IPM in a 48-year-old man who presented with a mass in the left groin, with inconclusive imaging. The typical histologic findings of smooth muscle actin, cyclin D1, and β-catenin positive intranodal spindle cell proliferation with characteristic palisades, amianthoid fibers, collagenous bodies, lack of atypia, and very low mitotic count, together with characteristic profile on ancillary testing, confirmed the diagnosis. In addition to staining with smooth muscle actin, cyclin D1 and β-catenin, immunohistochemical studies showed focal positivity with desmin, a finding previously reported in 2 of the published cases. Surgical excision is usually curative, with a 6% recurrence rate and no reported cases of locally aggressive disease or malignant transformation.
Conclusions
Although rare, IPM should be included in the differential diagnosis of isolated lymphadenopathy.
... As mentioned before CyclinD1 expression suggests the possible role of the cell cycle regulatory genes in the pathogenesis of IPM. Neoplastic cells are positive for beta-catenin and the Ki-67 index is generally low; less than 1% 13,17,22 . There is relation between nuclear beta-catenin and cyclinD1 expression within cells 27 . ...
Intranodal palisaded myofibroblastoma (IPM) is a kind of mesenchymal tumor with benign behaviour. The origin of this tumor is differentiated smooth muscle cells and myofibroblasts. This is a rare entity and differential diagnosis from malignant tumors is important for clinicians and pathologists. The etiology has not been explained adequately. Age range is between 2nd and 8th decades of the life and it is seen more frequently in males. Inguinal region is the most common localization but has been reported in other localizations including submandibular and retroperitoneal areas. Total excision of the tumor is the treatment in these cases. Recurrence is very rare and there is no report about metastasis. In conclusion IPM is a rare entity and it is commonly misdiagnosed as metastasis. Kaposi Sarcoma and schwannoma are the most common two spindle cell neoplasias. Be aware of this unique entity is important because wrong diagnosis causes dangerous management strategies.
Introduction:
Intranodal palisaded myofibroblastoma (IPM) is an exceedingly rare benign mesenchymal tumor of the lymph nodes. Magnetic resonance imaging (MRI) findings are unspecific, which may present diagnostic challenges to fine-needle aspiration cytology (FNAC). The histological and immunohistochemical features of IPM are unique.
Case report:
A previously healthy 40-year-old male patient presented a slow-growing solitary left inguinal mass. FNAC revealed clustered cells within a metachromatic stroma, single spindle cells without atypia, hemosiderin pigment, and siderophages. An MRI showed a central hyperintense septum in fat-suppressed, T2-weighted sequences. The excised lymph node contained central haphazard fascicles of spindle cells with focal nuclear palisading, hemosiderin pigment, extravasated erythrocytes, and hemorrhagic areas. Vimentin and smooth muscle actin were diffusely positive. Amianthoid collagen fibers were not clearly observed.
Conclusion:
IPM is an extremely rare mesenchymal benign intranodal tumor that should be included in the differential diagnosis of spindle cell lesions in the inguinal region.
Intranodal palisaded myofibroblastoma is a rare lymph node mesenchymal neoplasm that most commonly arises in inguinal lymph nodes. There is limited data about cytologic features of this tumor and its diagnostic pitfalls. The combination of bland appearing spindle cells, fibrillary matrix, and hemosiderin pigments are the characteristic features of this neoplasm in cytologic specimens.
