Differentiation of Desmoplastic Spitz Nevus from Similar Conditions

( Min-woo Kim ),( Ji Soo Lim ),( Yun Seon Choe ),( Jung Ho Kim ),( Hyun-sun Yoon ),( Soyun Cho ),( Hyun-sun Park ) 대한피부과학회 2016 대한피부과학회지 Vol.54 No.9

The diagnosis of classic Spitz nevus with characteristic histopathologic findings is often straightforward, but unusual variants can cause diagnostic difficulties. Desmoplastic Spitz nevus (DSN) is of particular importance, as its differential diagnosis from other diseases, including desmoplastic malignant melanoma (DMM), is essential but often difficult¹. A 38-year-old Caucasian woman presented with a 6-mm brownish papule of unknown onset on the dorsum of her left hand (Fig. 1A). She did not report any change in the papule size, trauma history, or related symptoms, but she wanted to have the lesion removed. Punch excision of the specimen revealed proliferation of individual spindle and epithelioid cells with scanty pigmentation within dense colla-genous dermal stroma (Fig. 1B, C). The specimen was focal positive for S-100 and HMB-45, positive for Melan-A, and 1% positive for Ki-67 (Fig. 2A∼C). The lesion did not recur after punch excision at the 1-year follow-up. Since its first report in 1975, there have been only a few case series of DSN owing to the rarity of this disease and its under-recognition, except for intermittent case reports^1-3. DSN usually presents as a small red-brown papule on the trunk and extremities. It can occur at any age, but is mostly observed in young adults, with a slight female predominance. The distinctive histopathologic features of DSN―an intradermal growth pattern of large spindle or epithelioid nevus cells embedded in a fibrotic stroma, sparse melanin pigment, no junctional activity, no Kamino bodies, no prominent nest formation―can aid its differentiation from clinical simulators. Additionally, immunohistochemistry is essential for a differential diagnosis. DSN tests positive for S-100, Melan-A, and HMB-45, whereas dermatofibroma is negative for all three³. Hypomelanotic blue nevus shows uniform positivity for HMB-45, whereas DSN shows differential expression in most spindled cells3. The distinction between DSN and DMM is the most important. DMM is more common in elderly patients and tends to occur on sun-damaged head and neck areas. It also shows cellular atypia, strong mitotic activity and Ki-67 expression, less frequent S-100 and Melan-A positivity, and almost exclusive negativity for HMB-45^2,3. Some researchers regarded DSN as an end stage of Spitz nevus that had lost continuity with the epidermis and undergone fibrosis. Paniago-Pereira et al.² also reported that DSNs occurred in patients older than 30 years. These findings suggest that desmoplasia might be an aging process of Spitz nevus. However, Barr et al.1 found no significant difference in patient age, disease duration, or trauma history between patients with DSN and common variants of Spitz nevus, and suggested that desmoplasia may be a tumor-induced reactive stromal induction rather than a regressive phenomenon. The pathogenesis of desmoplasia has not yet been clearly elucidated. Moreover, it is controversial whether DSN should be regarded as a variant of Spitz nevus or whether it belongs to a spectrum of desmoplastic nevus as a distinctive entity^3,4. Some researchers5 suggested strict diagnostic criteria for de-smoplastic nevus, including greater cellularity in the super-ficial portion, and a mixture of melanocytic nevus cells, ovoid and dendritic melanocytes, and spitzoid melanocytes. Further, they mentioned that lesions in which one particular type of melanocyte predominates over others are more likely to represent DSN. Dermoscopic findings can also aid the distinction, because DSN shows dotted vessels and reticular depigmentation whereas desmoplastic nevus demonstrates a delicate pigment network over a pinkish background⁴. Although it is regrettable that we did not acquire dermoscopic image to support the diagnosis, our case overall seems more com-patible with DSN. However, the probability of a morphologic spectrum that embraces DSN and desmoplastic nevus cannot be excluded, and requires further studies. Here, we report an unusual desmoplastic variant of Spitz nevus with a literature review, and propose keynotes for differential diagnosis from its simulators, especially DMM.

Unusual case of desmoplastic fibroblastoma (collagenous fibroma) on the toe

( Joon Won Huh ),( Ji Sook Yoo ),( Young In Jeong ),( Min Soo Kim ),( Kwang Hyun Choi ),( Hyang Joon Park ),( Mihn Sook Jue ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Desmoplastic fibroblastoma is a rare benign soft tissue tumor of fibroblast origin that presents a slowly growing, painless, fibroproliferative mass located in the subcutaneous tissue or just deep to skeletal muscle. It occurs commonly in the upper extremity such as shoulder and upper arm, and lower extremity, followed by head and neck region. However, the occurrence on the toe was rarely reported. A 70-year-old man presented a painless, slow growing, soft tumor on the left fifth toe. On physical examination, a 1 cm flesh colored, pedunculated mass was located on the left fifth toe. Histopathologic examination showed well-circumscribed mass that consisted of scattered stellate or spindle fibroblasts in collagenous matrix without atypia, which was consistent with desmoplastic fibroblastoma. Desmoplastic fibroblastoma was rarely reported in the dermatologic field and unfamiliar to dermatologist. In Korea, only 2 cases of desmoplastic fibroblastoma have been reported so far. We here report a rare case of desmoplastic fibroblastoma with unusual appearance on the toe.

지선모반에서 발생한 결합조직형성 모종

심형섭,정성노,권호,임영민,이은정 대한성형외과학회 2008 Archives of Plastic Surgery Vol.35 No.1

Purpose: Desmoplastic trichilemmoma is a rare variant of trichilemmoma. Histologically, it has a typical characteristic of trichilemmoma with epithelium of central portion and dense fibrous interstitium. There are only 4 reported cases of desmoplastic trichilemmoma arised in a nevus sebaceus, so we present a case of desmoplastic trichilemmoma arised in a nevus sebaceus with literature review.Methods: A 46-year-old female was clinically diagnosed as nevus sebaceous on left side of the forehead. Considering the facial contour, the mass was totally excised elliptically and direct closure was feasible with undermining subcutaneous layer.Results: Pathology report confirmed desmoplastic trichilemmoma developed from a nevus sebaceus and all tumor margins were negative. There were no evidences of tumor recurrence after surgical treatment.Conclusion: Desmoplastic trichilemmoma developed from a nevus sebaceus is a very rare tumor. Variant tumors can be developed from nevus sebaceus, so surgeon should be cautious in excising the mass totally and confirm the final pathology report.

눈꺼풀에 발생한 결합조직형성모종 1예

이기웅,지미정 대한안과학회 2018 대한안과학회지 Vol.59 No.4

Purpose: Desmoplastic trichilemmoma is a rare variant of trichilemmoma first described in 1990. Desmoplastic trichilemmoma on the eyelid has not been previously reported in Korea. We report our experience with a case of desmoplastic trichilemmoma of the eyelid. Case summary: A 72-year-old male patient presented with a round mass on the upper eyelid, which was noticed 1 year prior and caused irritation and itching. Excisional biopsy of the mass was performed. Histopathological examination revealed findings suggestive of a desmoplastic trichilemmoma. There was no local recurrence during the 2-year follow-up. Conclusions: Desmoplastic trichilemmoma should be considered when determining the type of eyelid mass. 목적: 결합조직형성모종(desmoplastic trichilemmoma)은 모종의 비교적 드문 변형으로 눈꺼풀에 발생한 예는 국내에 보고된 바가 없어 이에 보고하고자 한다. 증례요약: 72세 남자 환자가 내원 1년 전부터 소양감을 동반한 좌측 위눈꺼풀에 둥근 종괴를 주소로 내원하였다. 진단적 절제 생검을 시행하였으며 조직검사상 결합조직형성모종을 진단받았다. 술 후 2년까지 종괴의 재발은 관찰되지 않았다. 결론: 결합조직형성모종은 눈꺼풀에 생긴 종괴를 감별할 때 고려되어야 한다.

Desmoplastic melanoma of the oral cavity: diagnostic pitfalls and clinical characteristics

Seung Ki Min,Joo Hee Jeong,Kang Min Ahn,Chong Woo Yoo,Joo Yong Park,Sung Weon Choi 대한구강악안면외과학회 2018 대한구강악안면외과학회지 Vol.44 No.2

Objectives: Desmoplastic melanoma of the oral cavity is an extremely rare condition that is often confused on initial diagnosis with non-melanotic benign lesion or spindle cell tumors. The purpose of this article was to raise awareness of the disease using a literature review. Materials and Methods: We analyzed 19 desmoplastic melanoma cases reported in the literature and added our experience. Data on clinical, histopathology, treatment, and survival were retrieved and analyzed. Survival analysis was by the Kaplan-Meier method. Results: Initial clinical and histopathological features were indistinctive, and a definite diagnosis of desmoplastic melanoma at initial assessment was possible in only 23.5% of cases. Among tests, immunohistochemical studies for S-100 and vimentin were all positive. The 5-year disease-free survival rate for oral desmoplastic melanoma was 0%, and the 5-year overall survival rate was 55.0%. Conclusion: Oral desmoplastic melanoma has a high percentage of initial misdiagnosis and propensity for local recurrence. Thus, careful initial diagnosis and adequate surgery may result in improved overall survival.

Desmoplastic Fibroma of Bone: Case Report

이상윤,하동호,김동원,김수진 대한영상의학회 2011 대한영상의학회지 Vol.64 No.5

Desmoplastic fibroma of bone is a rare benign primary bone tumor that histologically resembles the extra-abdominal desmoid tumor of soft tissues. It is a nonmetastasizing, but locally aggressive tumor that is similar to a desmoid tumor of the soft tissues, and so it is considered “semimalignant”. According to a previous report on a series of bone tumors, the incidence rate of desmoplastic fibroma was 0.1-0.3%. Its rarity results in radiologists having a tendency of overlooking the possibility of desmoplastic fibroma of bone during the imaging readings. We report on the imaging findings of desmoplastic fibroma of bone with a review of the relevant literature.

Imaging Findings of Desmoplastic Fibroma Rarely Involving the Clavicle: Case Report

강동민,정선관,손영준,김헌수 대한영상의학회 2014 Korean Journal of Radiology Vol.15 No.1

Desmoplastic fibroma of bone is a rare locally aggressive, but non-metastatic tumor. In this case report, we present a desmoplastic fibroma in an unusual location, the clavicle. Desmoplastic fibroma involving the clavicle is extremely rare, with only 2 reported cases before 1985. We report the imaging findings of a desmoplastic fibroma of the clavicle with a review of the relevant literature.

A case of desmoplastic nevus

( Min Woo Kim ),( Hyun Sun Yoon ),( Soyun Cho ),( Hyun Sun Park ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Desmoplastic nevus (DN) is a rare benign melanocytic proliferation which was first described by Reed et al.Clinically, DN usually presents as a small, flesh-colored or erythematous or slightly pigmented papule or nodule ranging from 2mm to 1cm in size. Its diagnosis is primarily based onhistopathologic features characterizedby intradermal growth pattern composed of large spindle or epithelioid nevus cells embedded within a fibrotic stroma, sparse or no melanin pigment, no junctional activity and rare mitotic figures. And immunohistochemistry can also aid differential diagnosis of DN with other dermal proliferative diseases. A 38-year-old Caucasian woman presented with 6mm sized slightly pigmented papule of unknown onset which was located on her left dorsum of hand. Punch biopsy was done and spindle to oval cell proliferations with scanty pigmentation were seen within surrounding dense collagenous dermal stroma. And the specimen was focal S-100 positive, Melan-A positive, focal HMB-45 positive and 1% positive in Ki-67. Based on abovementioned findings, the lesion was diagnosed as desmoplastic nevus. Dermatologists should be aware of this entity, because its differential diagnosis from other diseases including desmoplastic melanoma is very important but often difficult owing to their similarity in cellular and stromal components.Therefore, we report a case of DN for educational purposes.

Desmoplastic Fibroblastoma of the Scalp Accompanied by Severe Pain; Unusual Location and Symptom

( Ji Hoon Yang ),( Je-byeong Chae ),( Chang-hun Huh ),( Jung-im Na ),( Kyoung-chan Park ),( Jung-won Shin ) 대한피부과학회 2018 Annals of Dermatology Vol.30 No.6

Desmoplastic fibroblastoma is a rare fibrous tumor that usually presents as a painless, slow-growing mass in the subcutaneous tissues and skeletal muscles. It has a wide anatomic distribution, with the most common involvement being the arm and shoulder. Here, we report a case of a tiny painful desmoplastic fibroblastoma arising on the scalp. According to a microscopic examination, this tumor was composed of spindle- shaped fibroblasts in the dense collagenous stroma. On immunohistochemical staining, tumor cells were positive for vimentin and negative for smooth muscle actin, CD34, and S100. Our case is unique in that desmoplastic fibroblastoma developed on the scalp and there was presence of pain despite its small size. (Ann Dermatol 30(6) 712∼715, 2018)

결합조직형성 모반(Desmoplastic Nevus) 1예

유정민,이현정,서은주,김진우 대한피부과학회 2002 大韓皮膚科學會誌 Vol.40 No.7

Desmoplastic nevus, a benign melanocytic neoplasm characterized by predominantly spindle-shaped nevus cells within a fibrotic stroma without junctional activity, nesting, or pigmentation, can be confused with fibrous lesions and other melanocytic proliferations, including desmoplastic melanoma. We report a rare case of desmoplastic nevus occurring in the left helix of the ear of a 25-year-old woman, which has typical histopathologic features of desmoplastic nevus.