"Bone in the penis" or fasciitis ossificans of the penis - a first time description of a pseudo-tumor at an extraordinary site.

BACKGROUND: Fasciitis ossificans is a rare subtype of nodular fasciitis, a benign soft tissue tumor with reactive characteristics. Due to its rapid growth, it is often misdiagnosed as a malignant tumor. While fasciitis ossificans commonly originates from the subcutaneous tissue and can appear throughout the body, it may also arise from extraordinary sites. CASE PRESENTATION: We report the first-ever documented case of fasciitis ossificans arising from the penis in a male patient who presented with a tumor on the glans penis. The tumor was surgically resected due to suspicion of penile cancer. Initial histopathological analysis led to a misdiagnosis of squamous cell carcinoma. However, pathological consultation ultimately confirmed the diagnosis of fasciitis ossificans of the penis originating from the glans penis by demonstrating ossification. CONCLUSION: This case underscores the importance of considering fasciitis ossificans in the differential diagnosis of soft tissue tumors, even in unusual locations such as penile soft tissue.

Poly-L-lactic acid/gelatin electrospun membrane-loaded bone marrow-derived mesenchymal stem cells attenuate erectile dysfunction caused by cavernous nerve injury.

Radical prostatectomy (RP) can cause neurogenic erectile dysfunction (ED), which negatively affects the quality of life of patients with prostate cancer. Currently, there is a dearth of effective therapeutic strategies. Although stem cell therapy is promising, direct cell transplantation to injured cavernous nerves is constrained by poor cell colonization. In this study, poly-L-lactic acid (PLLA)/gelatin electrospun membranes (PGEM) were fabricated to load bone marrow-derived mesenchymal stem cells (BM-MSCs) as a patch to be placed on injured nerves to alleviate ED. This study aimed to establish a promising and innovative approach to mitigate neurogenic ED post-RP and lay the foundation for modifying surgical procedures. Electrospinning and molecular biotechnology were performed in vitro and in vivo, respectively. It was observed that PGEM enhanced the performance of BM-MSCs and Schwann cells due to their excellent mechanical properties and biocompatibility. The transplanted PGEM and loaded BM-MSCs synergistically improved bilateral cavernous nerve injury-related ED and the corresponding histopathological changes. Nevertheless, transplantation of BM-MSCs alone has been verified to be ineffective. Overall, PGEM can serve as an ideal carrier to supply a more suitable survival environment for BM-MSCs and Schwann cells, thereby promoting the recovery of injured cavernous nerves and erectile function.

Soft tissue tumours of the penis. The 30-year Istituto Nazionale Tumori di Milano experience.

Objective: Small series and individual cases of penile soft tissue tumours are reported in the literature: these are rare tumours that represent less than 5% of all penile tumours. Methods: Penile soft tissue tumours were collected from the archive of the Department of Pathology at the Istituto Nazionale dei Tumori of Milan between January 1990 and October 2021. All available medical records were retrieved and reviewed to obtain clinical information. Results: Our series refers to the 30-year experience of highlighting the heterogeneity in the presentation and microscopic features of these rare sarcomas. 18 penile soft tissue tumours are described, 4 benign and 14 malignant. The mean age at diagnosis was 58.2 years (range 24-96 years) and 53.6 years among malignancies (range 24-89). The most frequent histotype was Kaposi's sarcoma (nr = 4) and very unusual histotypes were observed, namely low-grade fibromyxoid sarcoma, synovial sarcoma, proximal type epithelioid sarcoma and the first reported case of dedifferentiated liposarcoma of the penis. Conclusions: Among sarcomas of the genitourinary tract, tumours of the soft tissues of the penis are the rarest. Penile sarcomas can present at a young age. Kaposi's sarcoma in HIV-negative patients has a favorable outcome, while deep sarcomas have an aggressive behavior and poor prognosis.

Diagnostically Challenging Multifocal Penile Epithelioid Hemangioma Successfully Treated With Doxorubicin Hydrochloride.

ABSTRACT: Epithelioid hemangioma (EH), also known as angiolymphoid hyperplasia with eosinophilia, is an unusual vascular proliferation that tends to manifest in the head and neck region. Its occurrence on the penis is rare, with only scarce reported cases in the literature. The histopathological examination of this condition poses a challenge because it shares similarities with other entities, such as epithelioid hemangioendothelioma, epithelioid angiosarcoma, cutaneous epithelioid angiomatous nodule, or Kaposi sarcoma (KS). The infrequency of EH in penile locations underscores the need for accurate diagnostic differentiation and tailored treatment strategies for this atypical presentation. This case report highlights a rare instance of multifocal penile EH. The patient's lesions exhibited distinctive histopathologic features, with extensive eosinophilic infiltration, presence of necrosis, and infiltration to subcutaneous fat. The patient was treated with doxorubicin, a chemotherapy drug, with a very good response. This successful therapeutic outcome underscores the potential efficacy of doxorubicin in the management of multifocal penile EH. The comprehensive analysis of this case contributes to our understanding of the clinical presentation, histopathologic features, and treatment modalities for this rare penile tumor, providing valuable insights for future clinical considerations.

Surgical management of urethral obstruction secondary to perineal liposarcoma in a dog: a case report.

BACKGROUND: Swelling of the perineal region in male dogs is most commonly caused by a perineal hernia. Clinical signs associated with perineal hernia are constipation, tenesmus or stranguria. This case report documents a rare cause of perineal swelling created by the growth of a malignant tumour leading to urethral obstruction and subsequent stranguria. CASE PRESENTATION: An 11-year-old neutered male German Shepherd was presented for swelling in the perineal region and stranguria for three days. Complete blood count and serum biochemistry were unremarkable. Ultrasound revealed a heterogeneous mass in the perineal region. Retrograde urethrography showed a severe narrowing of the urethra caudal to the pelvis. A fine-needle aspirate of the mass was highly suspicious for liposarcoma. Staging was performed by computed tomography (CT) of the thorax and abdomen. Total penile amputation in combination with pubic-ischial pelvic osteotomy, transposition of the remaining urethra through the inguinal canal, V-Y-plasty cranial to the prepuce and preputial urethrostomy were performed to remove the tumour. Histopathology confirmed a well-differentiated liposarcoma with complete histological margins. Six months after the surgery the dog was doing well and there were no signs indicating local tumour recurrence. CONCLUSIONS: Wide surgical excision is generally recommended for soft tissue sarcomas, however this is sometimes not feasible for large tumours. In the case reported here, tumour resection was achieved by a combination of several surgical techniques with a good clinical outcome.

Primary preputial reconstruction following surgical excision of cutaneous mast cell tumours without penile amputation in eight dogs.

CASE HISTORY: Medical records from a single referral hospital (Davies Veterinary Specialists, Hitchin, UK) were reviewed to identify dogs (n = 8) with preputial cutaneous mast cell tumours (CMCT) that underwent surgical excision and primary preputial reconstruction, preserving the penis and urethra, after clients declined alternatives such as penile amputation and urethrostomy, from June 2017-June 2022. CLINICAL FINDINGS: Tumours had a median diameter of 21.5 (min 15, max 30) mm, were located cranioventrally (3/8), caudoventrally (1/8), laterally (2/8) and dorsally (2/8) relative to the prepuce and were diagnosed as CMCT based on cytology. No dogs had hepatic or splenic metastasis on cytology but inguinal lymph node metastasis was identified in 3/4 dogs sampled. TREATMENT AND OUTCOME: The owners of all dogs had declined penile amputation and scrotal urethrostomy. The CMCT were excised and primary reconstruction of the prepuce performed. Surgical lateral margins of 10, 20 or 30 mm were used and the deep margin excised the inner preputial lamina or underlying muscular fascia. The deep margin for caudoventral CMCT involved excision of the underlying SC adipose tissue. Preputial advancement was performed in 3/8 dogs to achieve adequate penile coverage. Histopathology confirmed all CMCT were Kiupel low grade, Patnaik grade II with complete margins in 6/8 dogs but identified metastasis only in one inguinal lymph node from one dog. Two dogs encountered minor complications (infection and a minor dehiscence) and one dog had a major complication (infection with major dehiscence). Median follow-up duration was 125 weeks, excluding one dog with 4 weeks of follow-up. None of the dogs experienced local recurrence or died of mast cell disease during the available follow-up period. CLINICAL RELEVANCE:  This clinical study evaluated a surgical alternative to penile amputation and advanced reconstructive techniques for Kuipel low/Patnaik grade II preputial CMCT when these procedures were declined by owners. Surgical excision of preputial CMCT with lateral margins of 10, 20 or 30 mm with primary preputial reconstruction is achievable with low morbidity and a good outcome when penile amputation and scrotal urethrostomy is not an option.

A pictorial review of scrotal and penile pathology on computed tomography.

Computed tomography (CT) may show a variety of scrotal and penile pathologic finding, but is usually not used as a first-line imaging due to its limited soft tissue contrast. Nonetheless, there are three main scenarios for imaging of the scrotum and penis with CT. Pathologies may be found incidentally in patients undergoing abdominal and pelvic CT scanning for different reasons. In emergency settings, CT is frequently performed, and the recognition of scrotal and penile pathologies by the reporting radiologist is crucial to ensure optimal patient treatment and outcome. If MRI scanning cannot be performed due to contraindications or is unavailable in resource, limited CT may be used for the further characterization of scrotal and penile pathology found on ultrasound. This pictorial review wants to familiarize general and emergency radiologists with the anatomy and possible pathological findings of the scrotum and penis on CT.

Association between HPV infection and penile cancer and penile intraepithelial neoplasia: A retrospective observational study.

BACKGROUND: Penile cancer is rising in most European countries. Several risk factors have been identified, namely human papillomavirus (HPV) infection. However, the exact role of HPV in penile cancer carcinogenesis is still unknown. Clarifying the contribution of HPV in penile cancer is crucial as it may improve prevention and treatment strategies. OBJECTIVE: To describe the characteristics of patients with penile cancer and penile intraepithelial neoplasia (PeIN), evaluate the prevalence of HPV-DNA in tumour tissue and identify differences between patients with and without HPV-DNA. METHODS: A retrospective observational study including patients with histological diagnosis of penile squamous cell carcinoma (SCC) or PeIN between 2012 and 2021 in a university hospital was carried out. HPV analysis was performed using Anyplex™ II HPV28 Detection that detects and identifies 28 HPV types. (sensitivity of 95.9%). RESULTS: A total of 25 patients were included. Most of the tumours identified were invasive SCC (n = 11) and SCC in situ (PeIN 3) (n = 8). PeIN1/2 was found in the remaining six patients. HPV-DNA was tested in all tissue specimens and was detected in 18 of them. High risk HPV DNA was identified in all positive HPV samples, except one. HPV types included in the nonavalent HPV vaccine were identified in 16 of the 18 samples positive for HPV-DNA. Stratifying patients according to HPV-DNA detection, we found that patients with HPV-DNA were younger (57.5 years vs. 70 years, p = 0.047), less likely to have phimosis (5.8% vs. 42.9%, p = 0.022) and more likely to have PeIN lesions than invasive SCC (85.7% vs. 27.8%, p = 0.025). CONCLUSION: This study shows a prevalence of HPV-DNA in penile SCC and premalignant lesions of 45.5% and 92.9%, respectively. Identifying HPV involvement in SCC and PeIN pathology has the potential to guide treatment and enhance follow-up strategies.

Extramedullary Plasmacytoma of the Penis as a First Manifestation of Multiple Myeloma: A Case Report.

INTRODUCTION: Plasmacytoma is a rare plasma-cell neoplasm, which includes bone and extramedullary types. While most cases occur in the head and neck, our report presents an unusual case of extramedullary plasmacytoma (EMP) in the penis, emphasizing the diverse locations of this condition. CASE PRESENTATION: An 88-year-old man, post-hydrocelectomy, presented with a palpable penile mass causing urinary symptoms. CT scans revealed a tumor with extracapsular spread and potential urethral involvement. Biopsy confirmed lymphoma, later identified as extramedullary plasmacytoma. A follow-up whole-body CT scan was performed, revealing multiple areas of bone rarefaction of the dens of the axis. His diagnosis has been further specified as multiple myeloma. Treatment with lenalidomide, bortezomib, and dexamethasone led to significant penile tumor reduction and improved voiding symptoms after three cycles. CONCLUSION: A rare case of primary EMP in the penis is reported, with only two documented cases of EMP in this location. The etiology of EMP remains unclear, possibly linked to chronic infection, irritation, or inflammation. EMP typically occurs in soft tissues, commonly in the head and neck, presenting as submucosal masses with symptoms in individuals aged 50-70. Diagnosis requires demonstrating monoclonal plasma cell infiltration and excluding multiple myeloma. While EMPs are often treated with radiotherapy, a patient with bone rarefaction suggestive of multiple myeloma requires first-line chemotherapy. This case highlights the importance of recognizing myeloma-defining events for appropriate treatment.

68 Ga-PSMA-11 PET/CT and 64 CuCl 2 PET/CT Help in Identifying Rare Metastatic Site of Penile Shaft in a Patient of Carcinoma Prostate.

ABSTRACT: A 71-year-old man, presenting with complaints of burning sensation and pain during urination, finally diagnosed with prostate carcinoma. Ultrasonography of the abdomen and pelvis revealed prostatomegaly. Serum PSA level was elevated, and TRUS-guided biopsy demonstrated acinar adenocarcinoma (Gleason score: 5 + 4 = 9). 68 Ga-PSMA-11 PET/CT for initial staging showed PSMA-avid enlarged prostate, pelvic lymphadenopathy, and focal PSMA uptake in the left side of the shaft of the penis. The patient also underwent a 64 CuCl 2 PET/CT, which demonstrated similar findings of enlarged prostate and adenopathy with focally increased tracer uptake in the shaft of the penis coinciding with the lesion observed on 68 Ga-PSMA-11 PET/CT, thereby detecting a rare metastatic site from carcinoma prostate.

The role of radiotherapy in the management of squamous cell cancer of the penis.

PURPOSE: To review the evidence for radiotherapy in the management of primary penile cancer, either as brachytherapy or external beam radiation, and the role of external beam radiotherapy in node positive penile cancer. METHODS: English language literature was reviewed for the past 3 decades. As penile cancer is uncommon in developed nations, high quality evidence to guide management is limited. Single institution reports often span decades during which time staging systems and treatments have evolved, reducing their relevance to current practice. Successful clinical trials require collaboration not only among disciplines but also among multiple institutions and nations. RESULTS: Radiotherapy is a definitive organ-preserving option for T1-T2 penile cancers. Interstitial brachytherapy is associated with penile preservation in 85% of men at 5 years, maintained in 70% by 10 years. Results of external radiotherapy are not quite as promising but nonetheless 60% of men will have an intact penis at 5 years. Inguino-pelvic external radiotherapy has been reported to increase overall survival when delivered as adjuvant treatment for men with pN3 groin but pN0 pelvic nodes, and improve disease specific survival for those with involved pelvic nodes. InPACT (ECOG-ACRIN_8134) is investigating the role of inguino-pelvic chemo-radiotherapy for men with pN3 inguinal nodes but imaging negative pelvic nodes. CONCLUSIONS: Radiotherapy has a well-defined role to play in treatment of squamous cell cancers of other sites, such as vulva, anal canal, uterine cervix and head and neck malignancies. Emerging data support the incorporation of radiotherapy into treatment paradigms for penile cancer.

The Effect of Pirfenidone on Peyronie Plaques and Erectile Function in a Peyronie's Rat Model.

OBJECTIVE: To investigate the anti-fibrotic effects of pirfenidone on Peyronie's disease in an experimental rat model with intracavernosal injection of TGF-ß and whether pirfenidone improves erectile function. STUDY DESIGN: Experimental study. Place and Duration of the Study: Faculty of Medical Experimental Animals and Research Laboratory, Trakya University, from January to March 2021. METHODOLOGY: In this study, 27 male Sprague Dawley rats were used, and three groups were randomly identified. The rats in Group 1 served as the control group. Group 2 was not treated, and Group 3 was treated with pirfenidone therapy. The rats in Group 3 were administered pirfenidone 30 mg/kg/day by oral gavage, every day for four weeks, three weeks after the start of the experiment. At the end of seven weeks, a haemodynamic study was performed with cavernosal nerve stimulation to evaluate the erectile function, the rats were sacrificed, and the penile tissues were evaluated immunohistochemically. RESULTS: MeICP/MIBP values were found to be higher in treated rats compared to rats in the untreated group but no statistically significant difference was found in MeICP/MIBP values between the control, Peyronie model, and treatment groups (p=0.25). According to the histopathological examination, the rate of fibrosis with H&E staining was mild (100%) in the control group, severe (100%) in the Peyronie group, and severe (87.5% severe and 12.5% moderate) in the Peyronie + treatment group. CONCLUSION: In the study, pirfenidone used in the treatment of Peyronie's disease had a positive effect on erectile function, though not considered statistically significant. It has been shown that it has no histopathological effect on Peyronie's plaques. KEY WORDS: Anti-fibrotic agent, Erectile function, Experimental study, Peyronie's disease, Pirfenidone.

Postoperative Metachronous Metastasis of Bladder Cancer to Penis: A Case Report.

BACKGROUND: Penile metastases are extremely rare events, originating primarily from primary pelvic tumours of the prostate, bladder, and gastrointestinal tract. The underlying mechanism of bladder cancer metastasis to the penis remains unclear. Metastasis to the penis is usually considered a late manifestation of systemic spread. Therefore, the prognosis of patients with penile metastasis remains poor and their survival period is short. Therefore, reporting this rare case will help to better understand the characteristics, diagnosis, and treatment processes of the disease, with the aim of improving the accuracy and efficiency of diagnosis and treatment. CASE DESCRIPTION: A 65-year-old male received transurethral resection of a bladder tumor. One year later, he underwent radical cystectomy because of the recurrence and progression of bladder cancer. Postoperative pathology demonstrated that the stage of bladder cancer was T3N0M0. One year later, he discovered a penile mass that gradually grew and became hard, accompanied by urinary retention, but without other clinical symptoms. The patient underwent a complete penectomy. Histopathology and immunohistochemistry results demonstrated the tumour's origin as a bladder urothelial carcinoma. The patient received systemic chemotherapy after surgery, but died 7 months later. CONCLUSIONS: Although penile metastasis of bladder cancer typically indicates an advanced stage of the malignant tumour and poor prognosis, we recommend that male patients with a history of bladder cancer should undergo a regular clinical examination of the penis to rapidly detect the disease and receive early treatment. In this case, despite treatment measures such as systemic chemotherapy and penectomy, the patient's prognosis remained poor.

HCG supplement did not accelerate tunica albuginea remodeling to facilitate penile growth.

Penile size is closely concerned and short penis contributes serious sexual dysfunction and tremendous psychological problems to couples. Androgen is essential for penile development and testosterone replacement is recommended to patients with micropenis. We previously proved that inhibiting activity of lysyl oxidase (Anti-lysyl oxidase, Anti-LOX) combined with vacuum erectile device (VED) lengthened penis by remodeling tunica albuginea. We thus explored whether HCG supplement could accelerate tunica albuginea remodeling (induced by Anti-LOX + VED) to promote penile growth. Forty-two SD male rats (4 weeks old) were purchased and divided into 7 groups: control, Anti-LOX, HCG, VED (with a negative aspirated pressure of - 300 mmHg), Anti-LOX + VED, HCG + VED, and Anti-LOX + HCG + VED. After an intervention for 4 weeks, all rats' penile length, exposed penile length, and erectile function were measured. Serum samples were collected to detect hormone levels and penile corpus cavernosum were harvested for histo-pathological analysis. All intervention groups showed significantly longer penis than controlled rats. Anti-LOX sharply increased penile length and exposed length by 15% and 9% respectively, this lengthening effect was more obvious in Anti-LOX + VED group (26% and 19%, respectively). Although HCG promoted penile length by 8%, this effect was slight for exposed length (3%). Moreover, Anti-LOX + HCG + VED dramatically increased penile length and exposed length by 22% and 18%, respectively, which was similar with that in Anti-LOX + VED (26% and 19%, respectively). HCG dramatically stimulated testosterone and dihydrotestosterone secretions than control group, whether with or without Anti-LOX and VED; while it induced more AR expression than other groups. Finally, all procedures did not improve or deteriorate normal erectile function. Although we verified that Anti-LOX + VED lengthened penis by inducing tunica albuginea remodeling, however, HCG supplement did not synergize with Anti-LOX + VED to accelerate albuginea remodeling to facilitate penile growth.

[Ocular and non-ocular squamous cell carcinomas in the Haflinger: Eight cases at the Institut Suisse de Médecine Equine (2015-2022)]. / Okuläre und nicht-okuläre Platten­-epithel­karzinome beim Haflinger: Acht Fälle am Institut Suisse de Médecine Equine (2015­2022).

INTRODUCTION: This case series describes the clinical course of ocular and non-ocular squamous cell carinoma (SCC) in the Haflinger horse and is intended to raise awareness of the high recurrence rate and tendency to metastasize. Eight Haflingers with histologically confirmed SCC were included, five ocular and three non-ocular, who were presented at the Institut Suisse de Médecine Équine (ISME) Bern between July 2015 and January 2022. The ocular SCC cases were all presented because of an apparent mass, which in most cases was post-treatment recurrence. The occurrence of recurrences was observed between 3 weeks and 16 years after initial therapy. Four of five Haflingers with ocular SCC had an enucleation, three of which were clinically normal at the time of the completion of this study, one case was euthanized due to confirmed metastases and one due to lameness. The result of enucleations for therapy of ocular SCC was good if no metastases occurred. Of the three non-ocular SCC cases, only one case, a penile SCC, had an apparent mass. Therapy was initiated in this case, while the other two cases were euthanized shortly after diagnosis due to the poor prognosis of SCC in the appropriate locations (maxillary sinus, mandible). Metastases occurred three and two years after removal of the primary tumor in ocular SCC in the scapula, liver and lungs and in non-ocular SCC from the penis to the nostrils. Since a postmortem pathological examination was not carried out on all Haflingers, further metastases cannot be ruled out. Haflingers with SCC should be monitored by a veterinarian over the long term, as recurrences and/or metastases can still occur years later.

INTRODUCTION: Cette série de cas décrit l'évolution clinique des carcinomes épidermoïdes (CE) oculaires et non oculaires chez le cheval Haflinger et vise à faire prendre conscience du taux de récidive élevé et de la tendance à la formation de métastases. Huit Haflinger avec un CE confirmé histologiquement, cinq oculaires et trois non-oculaires, qui ont été présentés à l'Institut Suisse de Médecine Équine (ISME) Berne entre juillet 2015 et janvier 2022, ont été inclus. Les cas de CE oculaires ont tous été présentés en raison d'une masse apparente, qui dans la plupart des cas était une récidive post-traitement. La survenue des récidives a été observée entre 3 semaines et 16 ans après le traitement initial. Quatre des cinq Haflinger atteints de CE oculaire ont subi une énucléation, dont trois étaient cliniquement normaux au moment de l'achèvement de l'étude, un cas ayant été euthanasié en raison de métastases confirmées et un autre en raison d'une boiterie. Le résultat des énucléations pour la thérapie du CE oculaire était bon s'il n'y avait pas de métastases. Sur les trois cas de CE non oculaires, seul un cas, un CE pénien, présentait une masse apparente. Le traitement a été initié dans ce cas, tandis que les deux autres cas ont été euthanasiés peu de temps après le diagnostic en raison du mauvais pronostic des CE dans les localisations constatées (sinus maxillaire, mandibule). Des métastases sont apparues trois et deux ans après l'ablation de la tumeur primaire dans le cas du CE oculaire, au niveau de l'omoplate, du foie et des poumons et, dans un cas de CE non oculaire, celui du pénis, aux narines. Étant donné que tous les Haflinger n'ont pas fait l'objet d'un examen pathologique post-mortem, on ne peut exclure la possibilité d'autres métastases. Les Haflinger atteints de CE doivent être suivis à long terme par un vétérinaire, car des récidives et/ou des métastases peuvent encore survenir des années plus tard.

The Spectrum of HPV-independent Penile Intraepithelial Neoplasia: A Proposal for Subclassification.

Compared with vulva, precursor lesions of human papillomavirus (HPV)-independent invasive squamous cell carcinoma (SCC) of the penis are insufficiently characterized. We analyzed the histologic and immunohistochemical characteristics of 70 peritumoral precursor lesions and correlated them with the histology and mutational profile of the adjacent HPV-negative invasive penile SCC. Atypical basal keratinocyte proliferation with variously elongated epithelial rete with premature squamatiziation, but regular superficial cornification, termed differentiated penile intraepithelial neoplasia (d-PeIN), were identified adjacent to 42/70 (60%) SCC (36/42 keratinizing ( P <0.001); 3 papillary, and 1 each verrucous, clear cell, sarcomatoid SCC). d-PeIN were associated with chronic inflammatory dermatoses (32/42; P <0.001), p53 overexpression (26/42; P <0.001), and hotspot mutations in TP53 (32/42; P <0.001), CDKN2A (26/42; P <0.001) or both (21/42; P =0.003) in the adjacent SCC. Cytoplasmic p16 ink4a overexpression in 5/42 d-PeIN correlated with CDKN2A missense mutations in the adjacent SCC. In all, 21/70 (30%) cornified verrucous or glycogenated verruciform precursors with minimal atypia and wild-type p53 (18/21; P <0.001) occurred adjacent to verrucous or papillary SCC (17/21; P <0.001) and keratinizing (4/21) SCC, which harbored mutations in HRAS and/or PIK3CA (12/21; P <0.004). Undifferentiated p16 ink4a -negative full-thickness precursors were identified in 7/70 (10%) SCC. Four histologically different HPV-independent penile precursor lesions can be assigned to 2 major genetic/biological pathways with characteristic highly differentiated precursors requiring different clinical management decisions. These include d-PeIN in chronic inflammatory dermatoses, with p53 overexpression and TP53/CDKN2A mutations, and the p53 wild-type verrucous and verruciform precursors unassociated with dermatoses, but with mutations in oncogenes PIK3CA and HRAS .

Large Solitary Fibrous Tumor (SFT) of the penis- a case report and review of literature.

BACKGROUND: Solitary fibrous tumors (SFTs) are very rare spindle cell neoplasms of mesenchymal origin with largely benign course of disease. Genital SFT's can be managed providing excellent functional and psychological outcomes by timely intervention. CASE PRESENTATION: We report the largest and possibly the second only reported case of penile SFT in a 34 year male presenting with a gradually increasing perineal mass with clinically normal appearing phallus. MRI revealed a 9.8 × 3.2 cm soft tissue mass arising from left corpora cavernosae, the mass was excised en-bloc via a perineal approach under spinal anaesthesia. Histopathology revealed spindle cell tumor embedded in myxohyaline stroma along with hyalinized vascular channels demonstrating IHC positivity for CD34 and STAT6. The patient is disease free post 2 years of resection with no sexual or urinary dysfunctions. CONCLUSION: Genital SFTs, although rare, should be considered in the differential diagnosis of well-circumscribed, painless, slow growing solid masses and histopathologists must be vigilant of its malignant characteristics.