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Diagnostic conundrums of schwannomas: two cases highlighting morphological extremes and diagnostic challenges in biopsy specimens of soft tissue tumors
Chankyung Kim, Yang-Guk Chung, Chan Kwon Jung
J Pathol Transl Med. 2023;57(5):278-283.   Published online August 24, 2023
DOI: https://doi.org/10.4132/jptm.2023.07.13
  • 1,640 View
  • 238 Download
AbstractAbstract PDF
Schwannomas are benign, slow-growing peripheral nerve sheath tumors commonly occurring in the head, neck, and flexor regions of the extremities. Although most schwannomas are easily diagnosable, their variable morphology can occasionally create difficulty in diagnosis. Reporting pathologists should be aware that schwannomas can exhibit a broad spectrum of morphological patterns. Clinical and radiological examinations can show correlation and should be performed, in conjunction with ancillary tests, when appropriate. Furthermore, deferring a definitive diagnosis until excision may be necessary for small biopsy specimens and frozen sections. This report underscores these challenges through examination of two unique schwannoma cases, one predominantly cellular and the other myxoid, both of which posed significant challenges in histological interpretation.
Imprint Cytology of Soft Tissue Myoepithelioma: A Case Study
Seok Ju Park, Ae Ri Kim, Mi Jin Gu, Joon Hyuk Choi, Duk Seop Shin
Korean J Pathol. 2013;47(3):299-303.   Published online June 25, 2013
DOI: https://doi.org/10.4132/KoreanJPathol.2013.47.3.299
  • 8,749 View
  • 50 Download
  • 7 Crossref
AbstractAbstract PDF

Soft tissue myoepithelioma is a rare neoplasm composed of myoepithelial cells. Here, we describe the cytologic features of soft tissue myoepithelioma arising on the right forearm in an 18-year-old man. The excised tumor (3.0×1.8×1.5 cm) was well-demarcated, yellow-gray, soft, and myxoid. The cytologic smears showed round to spindle, epithelioid, and plasmacytoid cells in the myxoid background. The nuclei were uniform, round to ovoid, with finely distributed chromatin and eosinophilic or pale cytoplasm. The tumor cells demonstrated immunoreactivity for cytokeratin (AE1/AE3), epithelial membrane antigen, S100 protein, and glial fibrillary acidic protein. Electron microscopy showed intermediate filaments, desmosomes, and basal lamina.

Citations

Citations to this article as recorded by  
  • Myoepithelial tumors of soft tissue and bone in children and young adults: A clinicopathologic study of 40 cases occurring in patients ≤ 21 Years of age
    Suzanna J. Logan, Carina A. Dehner, Fatimah I. Alruwaii, Nasir Ud Din, Damon R. Olson, Karen J. Fritchie, Gregory W. Charville, Melissa M. Blessing, Andrew L. Folpe
    Human Pathology.2024; 149: 10.     CrossRef
  • Fine-needle aspiration cytopathology of soft tissue myoepithelioma: an analysis of seven cases
    Paul E. Wakely, Momin T. Siddiqui
    Journal of the American Society of Cytopathology.2022; 11(1): 31.     CrossRef
  • Cytology‐histology correlation of myoepithelial tumors harboring EWSR1‐POU5F1 fusions: A report of two cases
    Ian A. Gelarden, Lucy Fu, Kai Lee Yap, Aida I. Richardson, Pauline M. Chou
    Diagnostic Cytopathology.2022;[Epub]     CrossRef
  • A case of myoepithelial carcinoma of the left shoulder
    Shuhei ISHII, Noriyuki FURUTA, Kyoko KOMATSU, Yoshiya SUGIURA, Noriko MOTOI, Yutaka TAKAZAWA, Yuko SUGIYAMA, Yuichi ISHIKAWA
    The Journal of the Japanese Society of Clinical Cytology.2018; 57(2): 129.     CrossRef
  • Fine‐needle aspiration of soft tissue myoepithelioma
    Gang Wang, Tracy Tucker, Tony L. Ng, Carlos F. Villamil, Malcolm M. Hayes
    Diagnostic Cytopathology.2016; 44(2): 152.     CrossRef
  • A case report of spindle cell myoepithelioma with extensive lipomatous metaplasia and thick collagen bundles in the submandibular gland
    Mi Jung Kwon, Hye Jeong Kim, Bumjung Park, Seong Jin Cho, Hyung Sik Shin, Hye‐Rim Park, Soo Kee Min, Jinwon Seo, Kyueng‐Whan Min, Eun Sook Nam
    Diagnostic Cytopathology.2016; 44(9): 764.     CrossRef
  • Myoepithelioma of soft tissue, a case report
    Hassania Ameurtesse, Leila Chbani, JM Coindre, Hinde Elfatemi, Toufik Harmouch, Afaf Amarti
    Research.2014;[Epub]     CrossRef
Original Article
A Proposal for Creating a Guideline for Cancer Registration of the Fibromatosis, PEComa Group, Malignant Lymphoma In Situ and Dendritic Cell Tumors (III)
Changyoung Yoo, Chang Suk Kang, Yoon La Choi, Hye Yoon Kang, Jin Man Kim, Young Hye Koh, Joo Hee Lee, Seung Sook Lee, In Sun Kim, Dong Hoon Kim, Yong Ku Park, Jin Hee Sohn
Korean J Pathol. 2012;46(5):436-442.   Published online October 25, 2012
DOI: https://doi.org/10.4132/KoreanJPathol.2012.46.5.436
  • 8,328 View
  • 52 Download
AbstractAbstract PDF
Background

Understanding the biologic behavior of a tumor is a prerequisite for tumor registration code assignment. The aim of this report was to propose appropriate behavior codes of the International Classification of Disease Oncology 3 (ICD-O3) to rare, yet pathologically interesting hematopoietic and soft tissue tumors.

Methods

The Study Group for Hematopathology, the Bone and Soft Tissue Pathology Study Group, and the Cancer Registration Committee prepared the questionnaire containing provisional behavior codes of selected diseases.

Results

In situ lesions of mantle cell and follicular lymphomas, dendritic cell tumors, and neoplasms with perivascular epithelioid cell differentiation (PEComa), not otherwise specified were classified as malignant (-/3). The fibromatosis group, with the exception of lipofibromatosis, was proposed as benign (-/0). Lipofibromatosis and several diseases that belong to the PEComa group were proposed as uncertain malignant potential (-/1). For the hematologic and soft tissue tumors, 274 and 288 members of the Korean Society of Pathologists, respectively, provided opinions through questionnaire, and most responders showed agreement with the provisional behavior code proposed.

Conclusions

The determination of behavior codes for the rare diseases described in this study, especially those of the PEComa group or malignant lymphoma, could be viewed as impractical and premature, but this study provides the basis for future research on this topic.

Case Reports
A Soft Tissue Perineurioma and a Hybrid Tumor of Perineurioma and Schwannoma
Ji Young Park, Nam Jo Park, Sang Pyo Kim, Kun Young Kwon, Sang Sook Lee
Korean J Pathol. 2012;46(1):75-78.   Published online February 23, 2012
DOI: https://doi.org/10.4132/KoreanJPathol.2012.46.1.75
  • 7,292 View
  • 62 Download
  • 14 Crossref
AbstractAbstract PDF

Perineuriomas are composed of differentiated perineurial cells. Perineuriomas have been recently recognized by the immunoreactivity for epithelial membrane antigen (EMA). Microscopically, perineuriomas show proliferation of spindle cells with wavy nuclei and delicate elongated bipolar cytoplasmic processes. The tumor cells are usually negative for the S-100 protein. Ultrastructurally, perineurial cells reveal slender, nontapered processes containing pinocytic vesicles and discontinuous basal lamina. Interestingly, hybrid tumors of benign peripheral nerve sheath tumor (PNST) have been recently reported by using immunohistochemical and ultrastructural investigations. Herein, we report a case of soft tissue perineurioma arising in the skin of a 56-year-old female; another case of a hybrid tumor of perineurioma and schwannoma in the posterior mediastinum occurred in a 53-year-old male, which is the first case of the hybrid PNST tumor reported in Korea.

Citations

Citations to this article as recorded by  
  • Neurogenic tumours of the posterior mediastinum and differential diagnosis considerations
    Michael A den Bakker, Annikka Weissferdt
    Histopathology.2024; 84(1): 238.     CrossRef
  • Hybrid tumors with perineurioma components: a systematic review of the literature and illustrative case
    Karina A. Lenartowicz, Dileep D. Monie, Kimberly K. Amrami, Christopher J. Klein, Caterina Giannini, Robert J. Spinner
    Acta Neurochirurgica.2022; 165(4): 935.     CrossRef
  • Hybrid Schwannoma/Perineurioma: Morphologic Variations and Genetic Profiles
    Takanori Hirose, Anna Kobayashi, Sumihito Nobusawa, Naoe Jimbo
    Applied Immunohistochemistry & Molecular Morphology.2021; 29(6): 433.     CrossRef
  • Mesenchymal Tumors of the Mediastinum: An Update on Diagnostic Approach
    Joon Hyuk Choi, Jae Y. Ro
    Advances in Anatomic Pathology.2021; 28(5): 351.     CrossRef
  • Neurogenic Tumors of the Mediastinum
    Erika F. Rodriguez, Robert Jones, Daniel Miller, Fausto J. Rodriguez
    Seminars in Diagnostic Pathology.2020; 37(4): 179.     CrossRef
  • A Rare Perineurioma/Granular Cell Tumor Hybrid Peripheral Nerve Sheath Tumor
    Koorosh Haghayeghi, Gladys Telang, Sonja Chen, Jack Bevivino, Shamlal Mangray, Yiang Hui, Leslie Robinson-Bostom
    The American Journal of Dermatopathology.2020; 42(10): 762.     CrossRef
  • Hybrid peripheral nerve sheath tumors
    Emine KILIÇ BAĞIR, Arbil AÇIKALIN, Gülfiliz GÖNLÜŞEN, Suzan ZORLUDEMİR, Mehmet Ali DEVECİ
    Cukurova Medical Journal.2019; 44(3): 804.     CrossRef
  • Primary intraosseous hybrid epithelioid schwannoma/perineurioma in the proximal tibia: a case report of benign hybrid neoplasm with local hypercellularity
    Yuejiao Lang, Dawei Liu, Pei Xiang, Jilin Wang, Yang Li
    Diagnostic Pathology.2019;[Epub]     CrossRef
  • Hybrid peripheral nerve sheath tumors: report of five cases and detailed review of literature
    Nasir Ud Din, Zubair Ahmad, Jamshid Abdul-Ghafar, Rashida Ahmed
    BMC Cancer.2017;[Epub]     CrossRef
  • Primary intraosseous hybrid nerve sheath tumor of femur: A hitherto undescribed occurrence in bone with secondary aneurysmal bone cyst formation resulting in pathological fracture
    Louis Tsun Cheung Chow
    Pathology - Research and Practice.2015; 211(5): 409.     CrossRef
  • Mesenchymal tumours of the mediastinum—part II
    Michael A. den Bakker, Alexander Marx, Kiyoshi Mukai, Philipp Ströbel
    Virchows Archiv.2015; 467(5): 501.     CrossRef
  • Primary pleural hybrid cellular schwannoma/perineurioma: A case report
    Danny Soria-Céspedes, Carlos Robles-Vidal, Arturo Gómez-González, Rosalinda Peñaloza-Ramírez, Carlos Ortiz-Hidalgo
    Respiratory Investigation.2014; 52(4): 269.     CrossRef
  • Hybrid peripheral nerve sheath tumour with intermingled perineuriomatous and schwannomatous areas reflected in skin ultrasonography image
    H. Saeki, K. Ito, Y. Nobeyama, T. Ishiji, M. Fukunaga, H. Nakagawa
    Clinical and Experimental Dermatology.2014; 39(6): 747.     CrossRef
  • Périneuriome extraneural des tissus mous localisé au nez
    A. Zaouak, R. Benmously, M. Belhadj Salah, W. Koubaa, A. Debbiche, I. Mokhtar
    Annales de Dermatologie et de Vénéréologie.2013; 140(8-9): 540.     CrossRef
High-Grade Myxofibrosarcoma Showing Pleomorphic Hyalinizing Angiectatic Tumor-like Appearance: A Case Report.
Mi Seon Kang, Hye Jung Jo, Sung Hee Son
Korean J Pathol. 2011;45:S1-S4.
DOI: https://doi.org/10.4132/KoreanJPathol.2011.45.S1.S1
  • 3,055 View
  • 19 Download
  • 1 Crossref
AbstractAbstract PDF
Myxofibrosarcomas (MFSs), which consist of multiple nodules with a variable cellular population in a myxoid matrix, are primarily located in subcutaneous tissue. Pleomorphic hyalinizing angiectatic tumors (PHATs) are rare soft-tissue tumors characterized by a proliferation of highly pleomorphic spindle or polygonal cells and abundant ectatic blood vessels in cellular or myxoid stroma. We present here an unusual case of a high-grade MFS with a PHAT-like appearance. A 67-year-old man presented with an asymptomatic subcutaneous mass in the right forearm. The tumor had myxoid, hypo-, and hypercellular areas with highly pleomorphic spindle or polygonal tumor cells that showed frequent mitoses and nuclear pseudoinclusions. Foci of punctuate necrosis and inflammatory infiltration were present throughout the tumor, and abundant ectatic, thick-walled vessels containing blood clots were noted. The tumor cells were immunohistochemically positive for vimentin but negative for CD34, S-100 protein, smooth muscle actin, desmin, and bcl-2.

Citations

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  • Children's kinetic family drawings and their internalizing problem behaviors
    Jin Kyung Kim, Joo Hyun Suh
    The Arts in Psychotherapy.2013; 40(2): 206.     CrossRef
Calcifying Aponeurotic Fibroma of the Elbow: A Case Report.
Mee Hye Oh, Eun Ah Jung, Ji Hye Lee, Hyun Deuk Cho, Jong Kyu Han, Yong Koo Park
Korean J Pathol. 2009;43(1):75-78.
DOI: https://doi.org/10.4132/KoreanJPathol.2009.43.1.75
  • 3,525 View
  • 34 Download
AbstractAbstract PDF
Calcifying aponeurotic fibroma is a rare soft tissue tumor that mostly occurs in the distal extremities of children and adolescents. We report here on a case of calcifying aponeurotic fibroma of the right elbow in an 8-year-old boy, and the tumor was diagnosed by surgical excision. The patient complained of painless swelling and mild limitation of the range of motion of the elbow joint. Radiologically, the mass was ill-defined and showed stippled calcification with shallow bony erosion. Microscopically, the tumor was composed of spindle cells with nodular deposits of hyalination and calcification, and these deposits were surrounded by palisading polygonal plump cells. Immunohistochemically, the tumor showed a diffuse positive expression for CD99 and negativity for smooth muscle actin, S-100 protein and CD34. The patient has been well with no signs of recurrence during the 42 months after surgery.
Original Article
Immunohistochemical Expression of p53 Protein, Estrogen and Progesterone Receptor in Soft Tissue Leiomyosarcoma and Its Significance.
Byung Heon Kim
Korean J Pathol. 1998;32(11):1015-1024.
  • 1,561 View
  • 10 Download
AbstractAbstract
This study was carried out to evaluate the expressions of the p53 protein, the estrogen receptor (ER) and the progesterone receptor (PR), as well as the relationship between their expressions and clinicopathologic prognostic factors with storage duration of a paraffin block, and correlation between the p53 protein, the ER and the PR expressions in 29 cases of leiomyosarcoma of soft tissue. The expressions of the p53 protein, the ER and the PR were semiquantiatively analyzed in paraffin sections by the immunohistochemical method out of 29 cases the p53 protein, ER and PR were expressed in 9 (31.0%), 2 (6.9%) and 5 (17.2%), respectively. The expression of the p53 protein was not significantly associated with sex, age, anatomic site, tumor size, tumor depth, histological differentiation or mitotic rate (p>0.05), but statistically correlated to storage duration of a paraffin block (p=0.028). There was no significant relationship between the expression of the ER and all the clinocopathological prognostic factors with storage duration of a paraffin block (p>0.05). The expression of the PR was related to the histological differentiation (p=0.02), but not related to other clinicopathological prognostic parameters and storage duration of a paraffin block (p>0.05). The expression of the p53 protein and the PR had a significant relationship (p=0.022), but the expression of the p53 protein and the ER had no significant correlation. In conclusion, these results suggest that the expression of the p53 protein and the PR may play a role in development and growth of soft tissue leiomyosarcoma. Further studies of large numbers are needed to clarify the exact relationship between tumorigenesis and the p53 and the PR expressions in leiomyosarcoma of soft tissue.
Case Reports
Chondroblastoma-like Extraskeletal Chondroma: A case report.
Jung Won Lee, Dae Su Kim, Mi Kyung Kim, Yeon Lim Suh
Korean J Pathol. 1999;33(1):55-58.
  • 1,722 View
  • 46 Download
AbstractAbstract PDF
Extraskeletal chondromas are relatively uncommon benign cartilaginous tumors of the soft tissue and well known to pose a considerable diagnostic problem because of histological variations including the immature appearance of their tumor cells. Recently, we have experienced a case of extraskeletal chondroma mimicking benign chondroblastoma. The patient was a 47-year-old woman who complained of a painful subcutaneous swelling on the radial aspect of 4th proximal interphalangeal (PIP) joint in the left hand for 6 months. Radiologic examination of the 4th finger revealed a 1cm-sized soft tissue mass. Histologically, the tumor was characterized by a lobulated mass which was composed of dense proliferation of chondroblast-like cells admixed with a few multinucleated giant cells of osteoclastic type. However, there were focal areas of typical chondroma which showed lace-like intense calcification around the differentiated chondrocytes.
Fibro-osseous Pseudotumor of the Digits: A case report .
In Seo Park, Jee Young Han, Hye Seung Han, Young Bae Kim, Young Chae Chu
Korean J Pathol. 1999;33(7):540-543.
  • 2,188 View
  • 43 Download
AbstractAbstract PDF
Fibro-osseous pseudotumor of the digits is a heterotopic ossification closely related to myositis ossificans and occurs in the subcutaneous tissue of the digits. This lesion is considered a reactive fibroblastic proliferation with metaplastic bone formation. We report a case of fibro-osseous pseudotumor of left index finger in a 28-year-old woman. She had had an ovoid smooth subcutaneous mass with tenderness on the left index finger for one month. In gross, the specimen consisted of a relatively circumscribed, rubbery soft mass with grayish white cut surface measuring 2.0 1.7 1.5 cm. Upon microscopic examination the lesion showed irregular multinodular growth with considerably variable cellularity. Because of the focal hypercellularity, cellular atypia, and increased mitotic activity this lesion may be confused with extraskeletal osteosarcoma or parosteal osteosarcoma. This rare lesion is curable by complete local excision.
Dendritic Myxofibrolipoma.
Sung Nam Kim, Kye Hyun Kwon, Yeon Lim Suh
Korean J Pathol. 2001;35(5):447-450.
  • 1,687 View
  • 21 Download
AbstractAbstract PDF
Dendritic myxofibrolipoma is a recently described disease entity that represents a distinctive benign soft tissue neoplasm showing the combined features of spindle cell lipoma and the solitary fibrous tumor. Immunohistochemical stains reveal a strong positivity for vimentin, CD34 and bcl-2, which highlight the dendritic nature of the tumor cells by demonstrating slender complex cytoplasmic prolongations. There have been 12 cases of dendritic myxofibrolipomas reported in literature. In Korea, none of the cases have been described. We report such a case with a 28-year-old man who had a palpable subcutaneous mass on his right shoulder for 4 months. Grossly, the removed mass measured 11X7X5 cm and appeared to be a well-encapsulated, lipomatous tumor with marked myxoid appearance. Microscopically, this tumor consisted of spindle cells admixed with dense collagen fibers and mature adipocytes in abundant myxoid stroma with high vascularity. Immunohistochemically, the tumor cells were strongly reactive for vimentin and CD34 and weakly reactive for bcl-2, and negative for S-100 protein.
Pleomorphic Hyalinizing Angiectatic Tumor of Soft Parts: A Case Report.
Young Chae Chu, Sun Keun Choi, In Suh Park, Hye Seung Han, Jee Young Han, Joon Mee Kim
Korean J Pathol. 2002;36(3):195-198.
  • 1,720 View
  • 16 Download
AbstractAbstract PDF
A case of rare pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts is reported. A 35-year-old woman presented with a subcutaneous solid mass in the left inguinal area, which had been present for 3 months, was presented to us. The tumor was histologically characterized by sheets of mitotically inactive oval and pleomorphic cells, mono-and multinucleated giant cells, intranuclear cytoplasmic inclusions, and prominent clusters of thinwalled ectatic vessels with perivascular hyalinization. A focal hemangiopericytoma-like vascular pattern, pseudovascular spaces, stromal collagen with degenerative change and abundant mast cells were observed. The tumor cells were reactive for vimentin and CD34. This tumor shared several features with malignant fibrous histiocytoma, ancient schwannoma, giant cell angiofibroma, giant cell fibroblastoma and solitary fibrous tumor. The patient was well with no evidence of disease for 10 months.
Original Articles
Fine Needle Aspiration Cytology of Parasitic Infestation in Soft Tissue.
Kyeong Mee Park, Ill Hyang Ko
Korean J Cytopathol. 1995;6(1):36-40.
  • 1,277 View
  • 13 Download
AbstractAbstract PDF
In the past, parasitic diseases were a major problem in public health in Korea. In recent years, however, nematodiasis that used be prevalent are no longer a serious problem. Instead some cestodiasis, particularly cysticercosis and sparganosis have become comparatively more important in recent years. Parasitic infestation of soft tissue is presented as a subcutaneous nodule or mass with nonspecific clinical manifestations.
Cytologic Features of Soft Tissue Lesions.
Soon Ae Oak, Gyung Yub Gong, Ghee Young Choe, Jur Yung Hch, Eun Sil Yu, In Chul Lee
Korean J Cytopathol. 1995;6(1):27-35.
  • 1,478 View
  • 13 Download
AbstractAbstract PDF
We reviewed 93 cases of fine needle aspiration of skin\subcutaneous and soft tissue lesions with histologic confirmation. On the basis of the most prominent cytologic features, morphologic classification of the aspirates was done. Neoplastic lesions of soft tissue were categorized as ; round cell, spindle cell, polygonal cell, well-differentiated and myxoid tumor. This classification is convenient to recognize and categorize most soft tissue tumors.
Case Report
Fine Needle Aspiration Cytology of Peripheral Neuroepithelioma of Soft Tissue: Report of A Case.
Yang Soon Park, Soon Ae Oak, Gyung Yub Gong, Ghee Young Choe, Joor Yung Huh, Eun Sil Yu, In Chul Lee
Korean J Cytopathol. 1995;6(1):62-66.
  • 1,388 View
  • 14 Download
AbstractAbstract PDF
Peripheral neuroepithelioma (PNE) of soft tissue is a malignant neuroectodermal tumor arising from peripheral(nonautonomic) nerve. It may occur in both children and adults, and are highly aggressive neoplasms that rapidly give rise to metastatic disease and death. We exprienced a case of peripheral neuroepithelioma of soft tissue in the upper arm in a 18-year-old female. Cytologic features revealed small round cells with scanty cytoplasm occurring both singly and in clusters. The clusters frequently tended to form Homer-Wright rosettes. The cells had a round to oval nucleus with fine chromatin and inconspicuous nucleoli in a hemorrhagic background.
Original Article
Imprint Cytologic Feature of Extraskeletal Osteosarcoma: A Case Report.
Mi Jin Gu, Young Kyung Bae, Mi Jin Kim, Joon Hyuk Choi, Won Hee Choi
Korean J Cytopathol. 2000;11(1):59-63.
  • 1,636 View
  • 18 Download
AbstractAbstract PDF
Extraskeletal osteosarcoma is an uncommon tumor originated from soft tissue without evidence of skeletal involvement. It usually affects adults and its common locations are extremity, buttock, and retroperitoneum. Although the histologic feature of this tumor is well known, there have been few reports on the fine needle aspiration cytologic findings. We report the imprint cytologic feature of extraskeletal osteosarcoma. The patient was a 49-year-old man with a mass of the left anterior chest for 2 years. On the imprint preparation, the smears showed malignant round, polygonal or spindle cells with coarsely clumped chromatin and occasionally prominent nucleoli. The malignant cells occur singly, in clusters, or associated with amorphous eosinophilic osteoid. Mitotic figures are also seen.

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