Cutaneous psammomatous melanotic schwannoma: non-recurrence with surgical excision

Laparoscopic surgery combined with the double-J tube implantation for the rare cystic-solid schwannoma of seminal vesicle: A Case Report and Literature Review

RATIONALE

Schwannoma is common in young and middle-aged people and occurs in the head, neck, posterior mediastinum, and retroperitoneal. Schwannoma, on the other hand, is a rare occurrence in the seminal vesicle. Early diagnosis and treatment are crucial since the disease can cause lower abdominal pain, nocturia, frequent urination, blood sperm, and other symptoms. There is no standard diagnostic or treatment guideline for seminal vesicle schwannomas currently. Therefore, the treatment experience relies on the few cases reported throughout the world.

PATIENT CONCERNS

A 45-year-old male patient discovered that the tumor beside the right side spermatophore is bigger than 3 years ago.

DIAGNOSIS

Schwannoma of seminal vesicle.

INTERVENTIONS

Ureter double-J tube implantation and laparoscopic surgery for schwannoma of seminal vesicle.

OUTCOMES

The operation process went smoothly. And the patient was no discomfort after half a year.

CONCLUSION

Schwannoma of the seminal vesicle is very rare in the clinic, and the imaging examination was not conclusive. The diagnosis mainly depends on pathological results. Surgical resection is the best treatment method for schwannoma. In surgery for schwannoma of seminal vesicle, combined with the ureter double-J tube implantation are many benefits. This case is an excellent example of the seminal vesicle schwannomas.

Melanotic Schwannoma of the Vulva: A Case Report and Review of the Literature

Melanotic schwannoma is a pigmented tumor of peripheral nerve differentiation. Primary cutaneous presentations are extremely rare, as the bulk of melanotic schwannomas tend to develop in paraspinal and axial sites. Tumors arise sporadically and in the setting of the Carney complex. Alterations in the gene encoding protein kinase A regulatory subunit-α (PRKAR1A) underlie most patients with the Carney complex and mediate melanotic schwannoma tumorigenesis. Melanotic schwannomas from noncutaneous sites can locally recur and metastasize widely, leading to a recent proposal to change the nomenclature to "malignant melanotic schwannian tumor." However, the clinicopathologic features of primary cutaneous melanotic schwannomas are relatively unexplored. We present a case of a nodule arising on the vulva of a 34-year-old woman. Microscopically, a dermal-based, heavily pigmented proliferation of plump spindled and epithelioid cells arrayed in nodules and fascicles was seen. Lesional cells stained positively for S100, Melan-A, and BAP1 but were negative for Prkar1α. Next-generation sequencing of a panel of 480 cancer-associated genes revealed that the tumor harbored a PRKAR1A p.S299fs truncating mutation and copy neutral loss of heterozygosity of chromosome 17q, the locus at which PRKAR1A resides. Importantly, no other genetic abnormalities or chromosomal copy number changes were identified. On the basis of combined histopathologic, immunohistochemical, and genetic features, a diagnosis of melanotic schwannoma was rendered. Overall, we present the first clinicopathologic description of a vulvar melanotic schwannoma, review the literature concerning cutaneous presentations of melanotic schwannoma, and propose that melanotic schwannian tumors native to skin may behave more indolently than their noncutaneous counterparts.

Pathology of Melanotic Schwannoma

CONTEXT.—

Melanotic schwannoma (MS) is a nerve sheath tumor with a uniform composition of variably melanin-producing Schwann cells and metastatic potential. The MS is an uncommon neoplasm, accounting for less than 1% of all nerve sheath tumors, with a predilection for spinal nerve involvement. Microscopically, the tumors are characterized by spindle and epithelioid cells arranged in interlacing fascicles, with marked accumulation of melanin in neoplastic cells and associated melanophages. The MSs are frequently associated with Carney complex, showing features of psammoma bodies and adipose-like cells. Strict criteria of malignancy in MS are not well developed, although a combination of worrisome histologic features (large, vesicular nuclei, with macronucleoli, brisk mitotic activity, and necrosis) raises concern for aggressive behavior.

OBJECTIVE.—

To review the current status of the MS literature, discussing putative etiology, histopathology, current genetics, and differential diagnoses, including overlap with other pigmented tumors.

DATA SOURCES.—

Search of PubMed (National Center for Biotechnology Information, Bethesda, Maryland) and the authors' own experiences.

CONCLUSIONS.—

The occurrence of MS at several unusual anatomic sites and its spectrum of morphologic patterns can result in significant diagnostic difficulty, and correct diagnosis is particularly important because of its high tendency to recur locally and to metastasize, which highlights the importance of diagnostic recognition, ancillary molecular genetic testing, and close clinical follow-up of patients with MS.

Pigmented Lesions of the Nervous System and the Neural Crest: Lessons From Embryology

Neurosurgeons encounter a number of pigmented tumors of the central nervous system in a variety of locations, including primary central nervous system melanoma, blue nevus of the spinal cord, and melanotic schwannoma. When examined through the lens of embryology, pigmented lesions share a unifying connection: They occur in structures that are neural crest cell derivatives. Here, we review the important progress made in the embryology of neural crest cells, present 3 cases of pigmented tumors of the nervous system, and discuss these clinical entities in the context of the development of melanoblasts. Pigmented lesions of the nervous system arise along neural crest cell migration routes and from neural crest-derived precursors. Awareness of the evolutionary clues of vertebrate pigmentation by the neurosurgical and neuro-oncological community at large is valuable for identifying pathogenic or therapeutic targets and for designing future research on nervous system pigmented lesions. When encountering such a lesion, clinicians should be aware of the embryological basis to direct additional evaluation, including genetic testing, and to work with the scientific community in better understanding these lesions and their relationship to neural crest developmental biology.

Psammomatous Melanotic Schwannoma: A Challenging Histological Diagnosis

Psammomatous melanotic schwannoma (PMS) is a rare pigmented tumor that can be part of the Carney complex. Here, we describe the case of a 35-year-old female patient presenting an isolated subcutaneous PMS. Histopathological analysis could not formally exclude the malignant nature of the tumor. The challenging histological diagnosis and consequently the management of the patient are described.

Melanotic cyst of L5 spinal root: A case report and review of literature

Till date, 85 cases of melanotic schwannoma and 11 cases of spinal root melanoma have been reported in literature. We are reporting a case of a 45-year-old lady who presented with primary low back pain, and magnetic resonance imaging of lumbo-sacral spine showed at left L5-S1 foraminal lesion extending to the para-spinal compartment. Hemi-laminectomy, facetectomy, and excision of the lesion were done. It was primarily a cystic lesion with attachment to the exiting spinal nerve root. Histopathology of the cyst wall showed a fibro-collagenous stroma with no specific cell lining containing melanin pigment suggestive of a melanotic cyst. The patient was completely relieved of the back pain, and had no recurrence over a follow-up period of one and half years. This case is probably the first reported predominantly cystic, pigmented lesion, affecting the spinal root.

Dumbbell-shaped C-2 psammomatous melanotic malignant schwannoma. Case report and review of the literature

The authors present the case of a dumbbell-shaped malignant psammomatous melanotic schwannoma of the upper cervical spine involving the C-2 sensory root. The family of the patient had a history of other malignant stromal tumors, without the Carney complex genetic pattern. The 30-year-old female patient complained of experiencing cervical pain and cervical muscle contractions for 6 months, and was admitted to the hospital. The cervical T1-weighted magnetic resonance (MR) images revealed the presence of a slightly hyperintense C2-3 intra-extradural lesion, moderately enhancing, which had eroded and enlarged the intervertebral foramen. The patient workup also included computed tomography scans and angiography. A posterior approach was used to perform a C2-3 hemilaminectomy, including opening of the dura mater and gross-total removal of the lesion. Histopathological examination of the lesion revealed it to be a malignant psammomatous melanotic schwannoma. The cerebrospinal MR image of the patient obtained at the 12-month follow-up examination demonstrated the presence of tumor progression into the subarachnoid space at the C-3 level. The strong malignancy potential of the lesion must be considered in the future management of the patient, especially due to the presence in the family of other stromal tumors such as gastrointestinal-stromal tumors and malignant melanomas. The authors review all the literature concerning melanotic schwannomas and report 105 cases of melanotic schwannoma that were not related to the Carney complex. The particular focus of their review is on the characteristics of the malignant progression of melanotic schwannoma, such as local recurrences, metastasis, and survival rate.

Inherited disposition to cardiac myxoma development

Carney complex is a genetic condition in which affected individuals develop benign tumours in various tissues, including the heart. Most individuals with Carney complex have a mutation in the PRKAR1A gene, which encodes the regulatory R1alpha subunit of protein kinase A - a significant component of the cyclic-AMP signalling pathway. Genetically engineered mutant Prkar1a mouse models show an increased propensity to develop tumours, and have established a role for R1alpha in initiating tumour formation and, potentially, in maintaining cell proliferation. Ongoing investigations are exploring the intersection of R1alpha-dependent cell signalling with other gene products such as perinatal myosin, mutation of which can also cause cardiac myxomas.

Clinical phenotypes and molecular genetic mechanisms of Carney complex

Carney complex is a familial multiple neoplasia disorder with characteristic features such as cardiac and cutaneous myxomas and spotty pigmentation of the skin. Clinical genetic analyses have shown that Carney complex is transmitted in an autosomal dominant way and can present with a wide array of other tumours, such as psammomatous melanotic schwannoma, testicular Sertoli-cell tumours, and pituitary adenomas. Molecular genetic studies show that mutations in the PRKAR1A gene, encoding the R1alpha regulatory subunit of cyclic-AMP-dependent protein kinase A, are the cause of Carney complex in most patients. Investigation of genetically engineered animal models confirms the role of PRKAR1A as a tumour suppressor and has begun to elaborate mechanisms underlying tumorigenesis in this disorder. Further genetic studies in human beings have highlighted novel variant phenotypes, such as congenital contractures, which are potentially associated with Carney complex, and have identified alternative genetic pathways to cardiac tumorigenesis, including mutation of the MYH8 gene that encodes perinatal myosin.