Primary Dermal Melanoma: A Case Report.

ABSTRACT: Primary dermal melanoma (PDM) is defined as a primary melanoma tumor confined to the dermis, subcutis, or both, without epidermal involvement. The significant overlap of histopathological features in PDM and cutaneous metastatic melanoma makes diagnostic accuracy of PDM challenging. We present a case of a 48-year-old man with a nontender 1.5 × 1.5 cm subcutaneous nodule on the left leg, which had been present for years. Biopsy revealed a dermal tumor with melanocytic differentiation noted to be positive for SOX-10. Additional pathology findings included a high Ki-67 proliferation index and a loss of p16 expression. Pathology reports were consistent with primary tumor stage 4a, and the patient was referred to surgical oncology where examination and workup demonstrated no evidence of the residual lesion representing a metastasis from a primary site. As PDM is histologically indistinguishable from melanoma metastasis to the skin, clues including a history of an evolving subepidermal nodule and exclusion of previous or concurrent melanomas can assist in its accurate diagnosis. Currently, a consensus on the criteria, staging, and management of PDM does not exist. Poorly defined diagnostic criteria and general lack of awareness of PDM result in high rates of incorrect and late-stage diagnoses. This case report highlights the importance of physician familiarity with PDM to ensure accurate recognition, evidence-based management, and improved patient outcomes.

A rare case of primary dermal clear cell sarcoma with focal epidermotropism: An entity difficult to distinguish from melanoma.

Clear cell sarcoma (CCS) is an uncommon soft-tissue sarcoma that only rarely arises within the dermis. It is challenging to distinguish dermal CCS from nodular, primary dermal, or metastatic melanoma, as they share morphologic features and immunoprofiles. We describe a dermal CCS in a 25-year-old man with a cutaneous groin mass. The lesion was initially diagnosed as melanoma, likely metastatic. On consultation, in addition to a melanoma-like tumor in the dermis, we identified focal infiltration of tumor cells into the overlying epidermis (epidermotropism), resembling primary nodular or metastatic melanoma. Given the patient's age and absence of a history of primary melanoma, fluorescence in situ hybridization (FISH) was performed, which revealed separation of the 5' and 3' EWSR1 probe signals on chromosome 22q12, prompting a diagnosis of CCS. Our case highlights the histopathological, immunohistochemical, and ultrastructural similarities between CCS and melanoma, and the consequent potential for major diagnostic confusion. In such cases, FISH analysis remains the key to diagnosis. CCS should be considered in patients with a melanoma-like tumor in the dermis or subcutaneous tissue without epidermal (or with minimal) involvement, or prior to diagnosing metastatic melanoma in the absence of a known history of primary melanoma, especially in young individuals.

Atypical cells on reflectance confocal microscopy may not represent melanoma: A case of axillary pigmented extramammary Paget disease.

Pigmented extramammary Paget disease (PEMPD) is a rare intraepithelial carcinoma which can clinically resemble other pigmented neoplasms. Similarities to melanoma on dermoscopy, histopathology, and reflectance confocal microscopy (RCM) increase the risk of misdiagnosis and, consequently, mismanagement. Here, we describe a case of a 67-year-old African American woman with a large, pigmented axillary patch that exhibited features of melanoma on RCM, guiding the clinician to perform an excisional biopsy. While traditional histopathology resembled melanoma, immunohistochemistry staining was performed and revealed PEMPD. We highlight an uncommon clinical presentation of PEMPD disease and identify morphologic mimickers of melanoma on RCM-as well as differentiating features.

Assessment of Shave Removal Without Further Excision in the Treatment of Spitz Nevi: A Retrospective Study of 58 Cases.

BACKGROUND: Spitz nevi (or tumors) are noncancerous growths that are found particularly in the pediatric population. Their histologic features overlap with melanoma, but they have a favorable prognosis, even when showing atypical features. OBJECTIVES: The aim of this research is to examine whether Spitz nevi can be sufficiently removed by adequate shave excisions without a subsequent excision. METHODS: Melan-A stained shave removal specimens (SRS) were obtained for 58 consecutively diagnosed Spitz nevi, along with slides of their postshave excision specimens. The SRS were reviewed for negative (clear) margins, defined as no neoplastic melanocytes detected within <0.2 mm of the deep and lateral margins of the specimen. Postshave excision specimens were reviewed for residual or recurrent lesions. RESULTS: The 15 shave excision specimens with negative margins had no corresponding residual lesions on postshave specimens. There were no recurrences in any of the cases in an average of 17 months of follow-up. CONCLUSIONS: Observation may be a logical approach for the management of Spitz nevi when shave removal achieves clear margins and the lesion lacks atypical features.

Dysplastic (or Atypical) Nevi Showing Moderate or Severe Atypia With Clear Margins on the Shave Removal Specimens Are Most Likely Completely Excised.

BACKGROUND: Dysplastic nevi (DN) are graded by their degree of atypia into 3 categories of mild, moderate, and severe. In many practices, DN with moderate or severe atypia are generally excised regardless of the status of the shave specimen margins. OBJECTIVE: With a new approach toward the margins on the shave removal specimens (SRS), the goal herein is to assess whether the shave removal procedure can sufficiently remove DN with moderate or severe atypia. METHODS: A total of 426 SRS diagnosed with DN showing moderate or severe atypia between January and December 2015 along with their post-shave excision specimens were reviewed. Based on the author's experience, clear or negative margins on the SRS were defined as neoplastic melanocytes confined within >0.2 mm of the lateral and deep specimen margins. The biopsy specimens were accompanied by Melan-A highlighting the subtle neoplastic cells. RESULTS: With a negative predictive value (NPV) of 98.4% (confidence interval: 97.2% to 100%, P < .001), DN showing moderate or severe atypia with clear margins are most likely removed by the shave procedure. CONCLUSION: Routine excision of DN showing moderate or severe atypia with clear margins on SRS is not necessary. Regular surveillance is sufficient.

Tenosynovial Giant Cell Tumor in the Dermis of the External Auditory Meatus.

A 26-year-old African American woman with a history of a recurring "oozing papule" in the right ear presented to the emergency department in July 2010 with a 2-month history of an enlarging, painful growth in the right ear canal. Physical examination revealed a 1-cm round cystic lesion along the right, anterior external auditory canal wall, just medial to the tragus. Initial diagnosis was an infected cyst of the external ear canal. The patient was instructed to follow-up with an ear, nose, and throat (ENT) office. Two months following the emergency department visit, inspection by ENT revealed a 3- to 4-mm round, firm subcutaneous nodule that did not extend into the ear canal or cartilage. According to the patient, this lesion had recurred with several infections. The lesion was biopsied in the outpatient setting and demonstrated ulceration with marked acute and chronic inflammation in addition to granulation tissue. Two months later, the lesion was surgically excised. The final diagnosis of giant cell tumor, tenosynovial type with lesion-free margins, and no involvement of the cartilage was made (Figures 1-3). No further treatment was recommended. Gross examination of the excised lesion revealed tan to white soft tissue measuring 1.0×0.7×0.3 cm. Results from factor XIII A immunostain was negative, confirming that the lesion did not represent an unusual variant of fibrous histiocytoma (Figure 4). To date, recurrence of this lesion has not been appreciated.

Metaplastic Breast Carcinoma Presenting as a Mixed Solid and Cystic Lesion.

The objective of this paper is to report a rare presentation of metaplastic breast carcinoma (MBC) as a mixed solid/cystic mass and emphasize the possibility of having a different biopsy report and final diagnosis. MBC is a rare type of breast cancer consisting of mesenchymal or mixed mesenchymal and epithelial components. It is believed to result from the conversion of glandular cells into non-glandular cells through various forms of mutations. It is common in females and more frequent in older women. MBC is a triple-negative breast cancer (progestin receptor, estrogen receptor, and human epidermal growth factor receptor 2) with a very poor prognosis when compared with other types of breast cancers. This is a case of an 84-year-old woman presenting with rapidly growing mixed solid and cystic breast mass with a final diagnosis of MBC. The initial biopsy report was high-grade ductal carcinoma in situ. This is an unusual presentation of MBC.

Langerhans Cells as Morphologic Mimickers of Atypical Melanocytes on Reflectance Confocal Microscopy: A Case Report and Review of the Literature.

Pagetoid spread of melanocytes in the epidermis is a common indicator of melanocytic atypia, both histopathologically and with reflectance confocal microscopy (RCM). Specifically on RCM, large, bright, atypical dendritic and/or roundish cells are characteristic of melanoma. However, intraepidermal Langerhans cells (ILC) create the potential for diagnostic ambiguity on RCM. We describe one case of a pigmented facial lesion that was initially diagnosed as lentigo maligna (LM) due to numerous atypical perifollicular dendritic cells on RCM. Additionally, we present the findings of a literature review for similar reported cases conducted by searching the following terms on PubMed: reflectance confocal microscopy, RCM, lentigo maligna, melanoma, Langerhans cells, dendritic cells, and atypical cells. In our case, the lesion was determined to be a solar lentigo on histopathology. Immunohistochemistry (IHC) with CD1a identified the atypical-appearing cells as ILC, as it did in 54 reported cases of benign lesions (benign melanocytic nevus, Sutton/halo nevus, labial melanotic macule, and solar lentigo) misdiagnosed as malignant on RCM (melanoma, lip melanoma, lentigo maligna, and LM melanoma). According to our case and the literature, both ILC and atypical melanocytes can present with atypical-appearing dendritic and/or roundish cells under RCM. Currently, there is no method to distinguish the two without IHC. Therefore, the presence of pagetoid cells should continue to alert the confocalist of a potential neoplastic process, prompting biopsy, histopathologic diagnosis, and IHC differentiation.

Recurrence of Dysplastic Nevi Is Strongly Associated with Extension of the Lesions to the Lateral Margins and into the Deep Margins through the Hair Follicles in the Original Shave Removal Specimens.

Melanocytic nevi, including dysplastic or atypical nevi (DN), can recur or persist following shave removal procedures, and recurrence may resemble melanoma, both clinically and histologically (pseudomelanoma). Recurrence may originate from proliferation of the remaining neoplastic melanocytes following incomplete removal. The present study determines the rate and etiology of this event. A cross-sectional analysis of 110 excision specimens showing histological recurrence was performed, and these specimens were compared to the slides of the original shave specimens showing mildly atypical DN. In the second portion of the study, a retrospective review of 167 cases with biopsy-proven mildly atypical DN which were followed up for at least two years was conducted to determine the rate of recurrence/persistence. When followed up for two years, DN, with positive shave margins, defined by extension or very close extension (≤0.2 mm) of the lesions to the lateral margins and into the deep margins through the hair follicles in the shave removal specimens, have a higher probability of recurrence than DN with negative (or clear) margins (odds ratio (OR) = 158; 95% confidence interval (CI) = 36.62-683; P < 0.001). The overall rate of histologically confirmed recurrence/persistence was approximately 10%.

Myeloid leukemia cutis in the setting of myelodysplastic syndrome: a crucial dermatological diagnosis.

Cutaneous involvement by myeloid leukemic cells is an unusual phenomenon. Clinical manifestations vary from erythematous papules to plum-colored plaques and nodules that may become purpuric and ulcerate. The definitive diagnosis of myeloid leukemia cutis requires the analysis of biopsy specimens using immunohistochemical staining to determine the expression of selective cell surface markers. We will review myeloid leukemia when first evident in the skin, particularly in the setting of myelodysplastic syndrome. The diagnosis of leukemia cutis in patients with myelodysplastic syndrome is indicative of concomitant or impending acute leukemic transformation. The early recognition and accurate identification of leukemic skin infiltrates in myelodysplastic patients is crucial, as this finding can have significant therapeutic and prognostic implications.

Arcuate, annular, and polycyclic inflammatory and infectious lesions.

Common shapes encountered in dermatologic diseases include linear, nummular, annular, polycyclic, and arciform. The last three have a relatively restricted differential, which must be entirely explored. It is not uncommon for a single disease to present in annular, arciform or polycyclic configurations; moreover, the lesions may evolve from being arciform to annular and then become polycyclic. Regardless, recognizing the arrangement of the defect will undoubtedly help in making a diagnosis and guiding subsequent management. We explore diseases that often present in annular, arciform, and/or polycyclic forms.