Desmoplastic fibroma (DF) is a benign, locally aggressive neoplasm that rarely occurs in the facial skeleton. It usually presents during the first three decades of life. Due to its aggressiveness and high recurrence rate, early diagnosis is imperative, and complete surgical removal of the lesion is the treatment of choice. Herein, we present three cases of DF namely a 2 year-old girl with a mandibular DF, a 9 year-old boy with a maxillary lesion and a 1.5-year old boy with a mandibular DF. Complete clinicopathological information, treatment plan and long-term follow-up of patients are discussed. Histopathologic features of 3 cases revealed non-capsulated spindle cell tumor with fascicular or swirling patterns in incisional biopsy. Immunohistochemical staining was performed to make a definitive diagnosis. Strongly positive nuclear immunoreactivity for β-catenin confirmed the diagnosis of desmoplastic fibroma in 3 cases. Segmental mandibulectomy, partial maxillectomy and hemimandibulectomy were done for the cases. There was no recurrence in our reported cases after 8 and 11 months and 3 years follow up, respectively. It is noteworthy that despite the aggressive nature of DF, young patients often respond well to wide resection treatment.

In this Annual Review Issue of The Journal of Pathology, we present 15 invited reviews on topical aspects of pathology, ranging from the impacts of the microbiome in human disease through mechanisms of cell death and autophagy to recent advances in immunity and the uses of genomics for understanding, classifying and treating human cancers. Each of the reviews is authored by experts in their fields and our intention is to provide comprehensive updates in specific areas of pathology in which there has been considerable recent progress. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

BACKGROUND: Desmoplastic melanoma (DM) is an uncommon malignancy associated with a high local recurrence rate. The aim of this systematic review was to determine the positivity rate of sentinel lymph node biopsy (SLNB) in patients with DM. The secondary outcome was to establish if SLNB is warranted for both pure DM (PDM) and mixed DM (MDM).
METHODS: A full systematic literature review of SLNB in DM was performed by two authors in January 2016. Ovid MEDLINE, Ovid EMBASE and the Cochrane Central Register of Controlled Trials were searched.
RESULTS: Sixteen studies involving 1519 patients having SLNB in DM were included, of which 99 patients had positive SLNB (6.5%). Two articles reported a significantly reduced disease-free survival (DFS) with positive SLNB and three published a reduced melanoma-specific survival (MSS). Six studies compared SLNB in MDM and PDM. Of the 275 patients, 38 (13.8%) had a positive SLNB in MDM compared to 17 of 313 patients (5.4%) with positive SLNB in PDM.
CONCLUSIONS: Rates of positive SLNB in DM are reduced compared to other variants of melanoma; however, nodal status may still predict DFS and MSS. MDM is associated with a higher rate of micro-metastases to regional lymph nodes than PDM, and DFS and MSS may be lesser in MDM than in PDM. We would recommend the consideration of SLNB in MDM. However, with such low rates of positive SLNB in PDM, and in the absence of high-risk features to stratify patients, we would not recommend SLNB in PDM.

Desmoplastic malignant pleural mesothelioma (DMM) is rare histological subtype of diffuse malignant pleural mesothelioma (MPM), accounting for 5-10 % of cases. It has a poor prognosis, with direct invasion of the chest wall or lungs and distant metastases. Its pathological characteristics include dense collagen fibers in a storiform pattern. Its pretreatment pathological diagnosis is difficult, with fibrous pleuritis and reactive mesothelial hyperplasia as potential differential diagnoses.
We retrospectively reviewed the medical charts of patients with MPM from 1996 to 2012. Among 60 patients with MPM, four patients with the desmoplastic subtype were identified and their clinical characteristics, including asbestos exposure, treatment, and prognosis, were reviewed. All of the patients with DMM were men, with a median age of 69 years (range: 63-74 years). All four patients had been exposed to asbestos. The definitive diagnosis was made histologically and the International Mesothelioma Interest Group classification was advanced (III/IV: 2/3) in all four patients. Three patients were treated with chemotherapy (two with cisplatin/pemetrexed and one with cisplatin/gemcitabine) and one patient underwent surgery. The median survival time in the patients with DMM was 3.8 months (range: 0.9-11.5 months), compared with 10.5 months in patients with other subtypes of MPM in our institution.
DMM continues to have a poor prognosis. It is important to recognize this variant and distinguish it from pleural plaques, non-specific reactive pleural fibrosis, pleurisy, and other lung diseases.

Fibromatoses are a heterogeneous group of distinct entities which differ in biological behaviour, but arehistologically very similar. This group of fibrous tumor or tumor like lesions, present considerable difficulties in pathologic diagnosis. Aggressive fibromatosis (AF) of the oral or para-oral structures is a very uncommon finding and its intra-osseous component is even relatively unusual. Such lesions with their origin from within the bone are termed desmoplastic fibromatosis (DF). These lesions must be distinguished from other fibroblastic tumors of the head and neck such as benign fibrous histiocytoma (BFH), fibrosarcoma, nerve sheath tumors and tumors of muscular origin. The major challenge in dealing with lesions of fibromatosis is to avoid an overdiagnosis of fibrosarcoma or an underdiagnosis of reactive fibrosis.Problems of differential diagnosis concern a wide range of diseases and immunohistochemical analysis may be helpful in diagnosis. With respect to the patient\'s post-operative well-being and if periodic follow-ups are guaranteed, the tumor should be carefully resected with only narrow safety margins. A rare case of aggressive desmoplastic fibromatosis in a 12-year-old girl is presented in this article with emphasis on the need and challenges for diagnosing such lesions as they have to be differentiated from other soft tissue tumors which display borderline pathological features regarding benign or malignant behaviour. Synonyms listed for the same include extra-abdominal desmoids, extra-abdominal fibromatosis, desmoids tumor, aggressive fibromatosis, juvenile desmoids-type fibromatosis, infantile fibromatosis.