Solitary cutaneous myofibroma of the glans penis

Myointimoma of the penis

Myointimoma is an uncommon, benign soft-tissue tumor derived from the intimal cells of blood vessels. Since little is known about this rare tumor entity, our aim is to describe an additional case and to perform the first literature review on this topic. A 49-year-old Caucasian man presented with a 12-month history of a palpable, firm, solitary lesion involving the glans penis. On physical examination, there was a 1 cm palpable, endophytic well-circumscribed nodule located to the left side of glans penis, close to the coronal sulcus, with disease-free external urethral orifice. The patient was submitted to complete excisional biopsy. A skin rhombus measuring 1.1 × 0.8 × 0.3 cm was removed and the biopsy sample, fixed in 10% formaldehyde, sent to Pathology. At the 18-month follow-up visit, the patient was clinically disease free. Histopathology revealed a multinodular intravascular proliferation of the corpus spongiosum. This myointimal proliferation comprised bland predominantly spindle cells in an abundant fibromyxoid stroma. Immunostains for smooth muscle actin (1A4), cytokeratins (AE1/AE3, CAM5.2), and CD34 were carried out using the avidin-biotin complex (ABC) immunoperoxidase method. Lesional cells displayed positivity for smooth muscle actin and negativity for cytokeratins and CD34. Myointimoma is confirmed to be a penile benign lesion that may be adequately treated with excisional biopsy. Even after incomplete or marginal removal, the penile lesion has been shown to remain stable overtime or regress. Differential diagnosis is essential to exclude similar histologic entities that could be more aggressive or have possible systemic implications.

Mesenchymal Neoplasms of the Genitourinary System: A Selected Review with Recent Advances in Clinical, Diagnostic, and Molecular Findings

Mesenchymal neoplasms of the genitourinary (GU) tract often pose considerable diagnostic challenges due to their wide morphologic spectrum, relative rarity, and unexpected incidence at GU sites. Soft tissue tumors arise throughout the GU tract, whether from adventitia surrounding or connective tissues within the kidneys, urinary bladder, and male and female genital organs. This selected article focuses on a subset of these lesions, ranging from benign to malignant and encompassing a range of patterns of mesenchymal differentiation, where recent scholarship has lent greater insight into their clinical, molecular, or diagnostic features.

Penile myofibroma occurring in a dorsal hood prepuce

Dorsal hood prepuce is a common congenital anomaly of the penis. Neoplasms of the prepuce are very rarely seen in children. We present an interesting case of a penile myofibroma encountered during circumcision of a dorsal hood foreskin in an 8-month-old infant.

Penile Myointimoma in Children and Adolescents: A Clinicopathologic Study of 5 Cases Supporting a Distinct Entity

Penile myointimoma is a rare benign myointimal proliferation occurring exclusively within the corpus spongiosum of the glans penis and is most commonly described in adult patients. To date, there is only one reported series of 10 penile myointimomas plus one case report, representing a total of 8 adults and 3 children/adolescents. We report 5 penile myointimomas occurring in 5 patients less than 18 years of age (age range 4 to 15 y). All patients presented with a mass lesion on the glans penis ranging in size from 0.4 to 1.8 cm. All 5 lesions had the classic morphologic appearance: myointimal proliferation of the preexisting vascular spaces of the corpus spongiosum, creating a multinodular/plexiform architecture. Immunohistochemically, all stained cases showed strong cytoplasmic immunoreactivity for smooth muscle actin in the lesional cells and a collarette of native smooth muscle highlighted by desmin. None of the lesions appeared completely excised, but all 5 patients were clinically free of disease at last clinical follow-up (2 to 45 mo). In summary, we report only the second series of this distinctive, relatively rare myointimal proliferation within the corpus spongiosum of the glans penis, expand the number of published cases occurring in the pediatric/adolescent population, and confirm the benign clinical course after a marginal or incomplete excision.

Pediatric penile tumors of mesenchymal origin

OBJECTIVES

To describe 2 cases of mesenchymal pediatric penile tumors in a 13-year-old boy and an 11-month-old infant. Mesenchymal tumors are rare in the male external genitalia.

METHODS

Two patients, one aged 13 years and one 11 months, presented with painless penile masses at the penoscrotal junction. The evaluation included serial clinical examinations and ultrasonography. Both lesions were surgically excised after increasing in size. Because of malignancy, the first patient underwent wide reexcision of the tumor site.

RESULTS

The pathologic findings of the first case were combined dermatofibrosarcoma protuberans, giant cell fibroblastoma, and fibrosarcoma, a malignant tumor. Immunohistochemical staining showed strong and diffuse CD34 cytoplasmic positivity in the giant cell fibroblastoma and dermatofibrosarcoma protuberans components; the dedifferentiated fibrosarcoma tumor cells were negative for this antibody. The second case was myofibroma, a benign fibroblastic tumor with a prominent myofibroblastic component that is congenital and tends to occur within the first few months after birth. Neither patient had recurrence at 16 months and 3 years of follow-up. To our knowledge, this is the first reported case of combined dermatofibrosarcoma protuberans, giant cell fibroblastoma, and fibrosarcoma of the penis and the second reported case of isolated penile myofibroma.

CONCLUSIONS

Penile tumors should be included in the differential diagnosis of pediatric penile masses. Surgical resection is often curative, but patients with malignant tumors should receive careful follow-up to monitor for recurrence.

Leiomyosarcoma of the Penis

Primary leiomyosarcomas of the penis are very rare. To date, less than 30 have been documented in the English language literature. In this report, we describe the clinical, histopathologic, and immunohistochemical findings in 14 cases retrieved from our files. The patients ranged in age from 43 to 62 years (mean age, 51 years) at the time of initial surgical resection. The tumors involved the prepuce (n = 1), prepuce and distal shaft (n = 1), circumcision scar line (n = 2), circumcision scar line and distal shaft (n = 1), shaft (n = 5), base of the penis (n = 3), and penis, not otherwise specified (n = 1). The lesions ranged in size from 0.5 to 6.0 cm (median size, 1.5 cm) in greatest dimension. Nine tumors were superficially located, two were of indeterminate depth, and three were deep-seated. The superficial tumors were relatively asymptomatic, and seven were reportedly present for 1 year to more than 20 years (median duration, 5 years) before medical attention was sought. In contrast, one deep-seated lesion caused dysuria and difficulty voiding, prompting the patient to seek a clinical opinion within only a few months of the apparent onset. Histologically, all tumors contained smooth muscle cells with both cytologic atypia and mitotic activity. Immunohistochemical studies were available for nine tumors, and immunoreactivity for desmin was present in all instances. All patients were initially treated with a local procedure. Follow-up information is available for 9 of the 14 patients (64%), with a median follow-up interval of 12 years 11 months. Three patients had multiple (two to four) local recurrences. Two of these patients were ultimately treated with a wide local excision or partial penectomy, and both were alive and well at last follow-up. In contrast, one patient, who had four local recurrences and refused a penectomy, developed a distant metastasis 10 months after the fourth recurrence. The best predictors of outcome are tumor depth and tumor size. Superficial leiomyosarcomas of the penis are optimally managed by wide local excision whenever this is technically feasible. Tumors with a deep-seated component may require more aggressive intervention to ensure complete removal.

Cutaneous smooth muscle neoplasms: clinical features, histologic findings, and treatment options

Cutaneous smooth muscle is present in 3 separate locations: arrector pili muscles, blood vessel walls, and genital/areolar skin. Benign or malignant smooth muscle neoplasms may arise from each of these locations. This review discusses the pathogenesis, clinical manifestations, histologic findings, prognosis, treatment options, and controversial areas of cutaneous smooth muscle neoplasms. ( J Am Acad Dermatol 2002;46:477-90.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be able to discuss the pathogenesis, clinical manifestations, histologic findings, prognosis, and treatment options of cutaneous smooth muscle neoplasms.

A distinctive myointimal proliferation ('myointimoma') involving the corpus spongiosum of the glans penis: a clinicopathologic and immunohistochemical analysis of 10 cases

This study details the clinicopathologic and immunohistochemical features associated with 10 cases of a distinctive myointimal proliferation involving the corpus spongiosum of the glans penis. Patients ranged in age from 2 to 61 years old (mean age, 29 yrs) and presented with a mass that varied in size from 0.5 to 1.9 cm in greatest dimension. The process was said to be present from 4 days to more than 6 months before surgical intervention. In each case, microscopic examination revealed almost identical histology. There was a prominent, often occlusive, fibrointimal proliferation with plexiform architecture involving the vasculature of the corpus spongiosum. The proliferation consisted of stellate-shaped and spindled cells embedded in abundant fibromyxoid matrix. Occasional lesional cells had well-developed myoid characteristics with moderately abundant eosinophilic cytoplasm, blunt-ended nuclei, and juxtanuclear vacuoles. Foci with degenerative changes, including "ghost cell" morphology, were also present. The myointimal process was extensively immunoreactive for alpha-smooth muscle actin, muscle-specific actin (HHF-35), and calponin, but it was minimally reactive for the D33 and D-ER-11 desmin clones. In contrast, native vascular smooth muscle encompassing the proliferation was strongly immunoreactive for all five markers. The myointimal cells were nonreactive for CD34, S-100 protein, and keratin. Factor VIIIrAg, CD31, and CD34 highlighted intact endothelial cells lining suboccluded vessels, scattered capillaries that penetrated the proliferation, and the normal uninvolved vasculature. The examined specimens were punch, incisional, or excisional biopsies, and in each instance, the process microscopically extended to the tissue margin. Follow-up data are available for 8 cases (median follow-up interval, 5 yrs 8 mos): one incompletely excised lesion with 6 months follow-up is stable but persistent, one lesion with 10 years follow-up regressed spontaneously after a punch biopsy, and the remaining six lesions have not recurred. A differential diagnosis of myofibroma, late-stage intravascular (nodular) fasciitis, vascular leiomyoma, and plexiform fibrohistiocytic tumor is discussed.

Postoperative/posttraumatic spindle cell nodule of the skin: the dermal analogue of nodular fasciitis

Spindle cell proliferations of the skin are diverse, both morphologically and mechanistically. The authors have encountered four examples of a distinctive reactive/reparative cutaneous spindle cell lesion that shows homology with ones seen in the genitourinary tract and oral cavity and that is known as "postoperative/posttraumatic spindle cell nodule" (PSCN). These occurred in the skin of the face and scalp (2 cases), arm (1 case), and vulvar skin (one case), and were clearly related historically to prior episodes of trauma. The proliferations were characterized by variably-apposed and cytologically-bland spindle cells with numerous mitotic figures, set in a highly vascular stroma containing extravasated erythrocytes and inflammatory cells. All lesions were immunoreactive for vimentin, actin, and desmin, with no labeling for keratin. Postoperative/posttraumatic spindle cell nodule of the skin is a significant pseudoneoplastic lesion that is related (and perhaps identical pathogenetically) to nodular fasciitis; as such, it may be mistaken for a sarcoma or a spindle cell carcinoma. Careful attention to clinicopathologic and histologic details should result in its accurate recognition.