BACKGROUND: Multiple osteochondromas is genetic disorder characterized by the formation of multiple benign cartilage-capped bone tumors, named osteochondromas, during skeletal development. The most feared complication is the secondary peripheral chondrosarcoma, a malignant cartilaginous neoplasm that arises from the chondroid cap of pre-existent osteochondromas. We conducted a retrospective cohort study on patients diagnosed and followed up from 1960 to 2019 to describe the clinical and pathological features of individuals affected by peripheral chondrosarcoma in multiple osteochondromas, to evaluate follow up information and individual outcome and to compare the results with literature. Data, including age, gender, site, histological grade, cartilage cap thickness, surgical treatments, surgical margins, genotype mutational status as well as treatment details were captured from the hospital electronic health records and from Registry of Multiple Osteochondromas. In addition, a complete histological review of all hematoxylin and eosin (H&E)-stained sections has been performed by expert pathologists.
RESULTS: One hundred five of the screened cases were included in the present study. The age at diagnosis of SPC ranges from 13 to 63, with median age at diagnosis of 34 years. The site most frequently affected by malignant degeneration was the pelvis (46 patients, 44%) with higher incidence in male patients (32 males vs.14 females). The second one was lower limbs (including femur, fibula, or tibia), identified in 35 patients. Histological information - available for 103 patients - showed: 59 patients with grade 1; 40 patients had a grade 2 and 4 patients had a grade 3. The most common surgical treatment was the complete resection, followed by debulking, amputation and partial resection. Most of cases did not have recurrence of the disease. Outcome in disease-free survival highlights that a worse course of the disease was associated with histological grade 2 or 3, and partial resection surgery. In most of analyzed cases (94%) a pathogenic variant was identified.
CONCLUSIONS: In conclusion, the present study gives an overview of the secondary peripheral chondrosarcomas, confirming that this disease represents an impacting complication for multiple osteochondromas patients and suggests that malignant transformation can occur also in younger patient, in a not irrelevant number of cases.

Persistent Müllerian Duct Syndrome (PMDS) is a rare autosomal recessive disorder of sex development characterized by the presence of fallopian tubes, uterus and upper one-third of the vagina in individuals with XY genotype and normal male phenotype. The main complications of PMDS are infertility and the rare risk of malignant degeneration of both testicular and Müllerian derivatives. We report the case of a 49-year-old man who, during repair of an incisional hernia, was incidentally found to have a uterine-like structure posterior to the bladder. In the past at the age of 18 months, he had undergone bilateral orchidopexies for bilateral cryptorchidism. The intraoperative decision was to preserve the uterine-like structure and make a more accurate diagnosis postoperatively. Evaluation revealed an XY chromosome and imaging consistent with PMDS. The patient was informed about the risk of neoplastic transformation of the residual Müller ducts and was offered surgical treatment, which he declined. Subsequent follow-up imaging studies, including testicular and pelvic ultrasound, were negative for findings suggestive of malignant testicular and Mullerian derivative degeneration. A review of the international literature showed that, when a decision is taken to remove the Mullerian derivatives, laparoscopy and especially robotic surgery allow for the successful removal of Müllerian derivatives. Whenever the removal of these structures is not possible or the patient refuses to undergo surgery, it is necessary to inform the patient of the need for adequate follow-up. Patients should undergo regular pelvic imaging examination and MRI might be a better method for that purpose.

BACKGROUND: Branch duct-intraductal papillary mucinous neoplasms (BD-IPMNs) are the most common pancreatic cystic tumors and have a low risk of malignant transformation. Features able to early identify high-risk BD-IPMNs are lacking, and guidelines currently rely on the occurrence of worrisome features (WF) and high-risk stigmata (HRS).
OBJECTIVE: In our study, we aimed to use a magnetic resonance imaging (MRI) radiomic model to identify features linked to a higher risk of malignant degeneration, and whether these appear before the occurrence of WF and HRS.
METHODS: We retrospectively evaluated adult patients with a known BD-IPMN who had had at least two contrast-enhanced MRI studies at our center and a 24-month minimum follow-up time. MRI acquisition protocol for the two examinations included pre- and post-contrast phases and diffusion-weighted imaging (DWI)/apparent diffusion coefficient (ADC) map. Patients were divided into two groups according to the development of WF or HRS at the end of the follow-up (Group 0 = no WF or HRS; Group 1 = WF or HRS). We segmented the MRI images and quantitative features were extracted and compared between the two groups. Features that showed significant differences (SF) were then included in a LASSO regression method to build a radiomic-based predictive model.
RESULTS: We included 50 patients: 31 in Group 0 and 19 in Group 1. No patients in this cohort developed HRS. At baseline, 47, 67, 38, and 68 SF were identified for pre-contrast T1-weighted (T1-W) sequence, post-contrast T1-W sequence, T2-weighted (T2- W) sequence, and ADC map, respectively. At the end of follow-up, we found 69, 78, 53, and 91 SF, respectively. The radiomic-based predictive model identified 16 SF: more particularly, 5 SF for pre-contrast T1-W sequence, 6 for post-contrast T1-W sequence, 3 for T2-W sequence, and 2 for ADC.
CONCLUSIONS: We identified radiomic features that correlate significantly with WF in patients with BD-IPMNs undergoing contrast-enhanced MRI. Our MRI-based radiomic model can predict the occurrence of WF.

UNASSIGNED: Although carcinomatous degeneration is a rare occurrence, some authors support the need for a histopathological examination after pilonidal cyst excision. Today, minimally invasive techniques are widely spread for the treatment of pilonidal sinus disease but opposed to standard procedures, these techniques could not allow to perform a histopathological examination because of the absence of a specimen. The aim of this two-institutions study is to evaluate whether histopathological examination of the pilonidal sinus excision material can be successfully performed after an endoscopic ablation of the cyst.
UNASSIGNED: We identified all consecutive patients from January 2021 to September 2021 with diagnosis of pilonidal sinus disease who underwent Video Assisted Ablation of Pilonidal Sinus (VAAPS) followed by histopathological examination.
UNASSIGNED: A total of 45 patients were included in the study. All patients were Caucasians and aged below 50 years. Nine of them underwent surgery due to recurrence of PSD. No evidence of malignancy was detected in the histopathological examination of the pilonidal sinus sampling material.
UNASSIGNED: We were able to send pilonidal sinus sampling material for a histopathological examination in all patients who underwent minimally invasive technique for the treatment of pilonidal sinus disease. No evidence of malignancy was found in any of the 45 samples. Our findings prove that minimally invasive ablation of pilonidal sinus does not preclude histopathological examination of the cysts.

Chronic inflammation, long implicated in the genesis of malignancy, is now understood to underlie an estimated 25% of all cancers. The most pertinent malignancies, to the plastic surgeon, associated with the degeneration of chronic inflammation include Marjolin\'s ulcer, breast implant-associated large cell lymphoma, radiation-induced sarcoma, and Kaposi\'s sarcoma. The cellular and genetic damage incurred by a prolonged inflammatory reaction is controlled by an increasingly understood cytokinetic system. Advances in understanding the chronic inflammatory cascade have yielded new therapeutics and therapeutic targets.

BACKGROUND: Although pilonidal sinus disease is common, development of associated malignancy is very rare. After surgical treatment, most surgeons send the excision material for a histopathological examination. The aim of this study was to examine whether it is necessary to routinely send the pilonidal sinus surgical excision material for this examination.
METHODS: The data of 3146 patients were retrospectively screened, and 2486 patients with available histopathological reports of the excision material were included in the study.
RESULTS: Of the 2486 patients included in the study, 2165 were men and 321 were women, and 94.7% of the patients were under the age of 50 years while 5.3% were 50 years or above. The rate of patients who underwent surgery due to recurrence was 1.2%. No malignancy was detected in any patient after the histopathological examination.
CONCLUSIONS: In this study, none of the pathology results was reported as malignant. This confirms that it is necessary to ask the question whether we should routinely send the surgical excision material for a histopathological examination.

\"Marjolin\'s ulcer\" is known as malignant degeneration of ancient burn scars, but both words can induce misdiagnosis. Malignant degeneration of scarring tissue can occur and can vary in its clinical, histological manifestations and its pre-existing skin lesions. We present several cases to substantiate our observations. \"Marjolin\'s ulcer\" is not synonym to an ulceration appeared on an old burn scar, transformed into squamous cell carcinoma.

Epitheloide angiomyolipoma (EAML) is a very rare type of benign mesenchymal angiomyolipoma. In contrast to classical angiomylipoma, lymph node metastases, local recurrence and distant metastases occur in one third of patients with EAML. We report the case of a 49-year-old patient with a large recurrence of EAML of the left kidney. According to the literature, this is the first case of a malignant EAML with local recurrence in Germany.

Hidradenitis suppurativa (acne inversa) is a chronic inflammatory follicular skin disease which leads to fistulae, abscesses and scarring. The Hurley classification is used to quantify the extent of the disease whereby stage III is associated with extensive disfiguring lesions. The most frequently used conservative treatment options are topical clindamycin, systemic antibiotics, e.g. clindamycin and rifampicin, anti-TNF antibodies and laser epilation. Complete excision of fistulae with or without plastic coverage of defects are the mainstays of surgical treatment. Preoperative and postoperative strategies to diminish tissue loss and options for recurrence prevention are discussed.

Chondrosarcoma is the second most common primary malignant bone tumor. While the majority arrive de novo, a minority arise from malignant transformation of benign neoplasms, such as osteochondromas. Rarely, chondrosarcomas have been found to originate from other preexisting lesions, such as synovial chondromatosis. A 44-year-old male with a history of a spinal osteochondroma presented with one year of left hip pain and decreased range of motion. On examination, he had a palpable, irregular fullness in the left groin that was minimally tender to palpation. Radiographs and CT of the hip showed extensive soft tissue calcifications and erosion of the femoral neck. The lesion was debulked surgically and histologically diagnosed as synovial osteochondromatosis with no evidence of atypia or cellularity. One year later, his residual disease progressed and resulted in increasingly limited range of motion. He underwent left total hip arthroplasty with simultaneous debulking and the lesion was once again diagnosed as synovial osteochondromatosis. Two months postoperatively, the patient developed a new focus of calcification around the hip joint that was thought to be recurrent disease. Six months later, due to worsening symptoms, he underwent a repeat CT scan. This scan demonstrated extensive intra-articular disease extending into the iliopsoas bursa and around total hip arthroplasty, as well as a new soft tissue nodule with foci of calcification in the left gluteus maximus. The new lesion was debulked surgically and diagnosed as a grade 1 chondrosarcoma. Chondrosarcoma arising from synovial chondromatosis is a rare presentation of the second most common primary malignant bone tumor. It typically presents as an indolent, slowly growing painful mass of large joints in middle aged men. Conventional radiography shows punctate opacities, while MRI and CT reveal diffuse soft tissue calcification and cortical erosion. Low-grade chondrosarcomas are treated with intralesional curettage and adjuvant therapy, while higher grade chondrosarcomas are treated with wide, en bloc excision. Malignant transformation should be considered in any patient presenting with worsening symptoms and a history of a benign bony lesion.