Soluble adenylyl cyclase antibody profile as a diagnostic adjunct in the assessment of pigmented lesions

Abstract

Objective: To investigate the usefulness of a novel marker for melanocytic proliferations.

Design: Using a novel monoclonal antibody against soluble adenylyl cyclase (sAC), various benign and malignant melanocytic proliferations were immunostained.

Setting: Weill Medical College of Cornell University dermatopathology laboratory.

Main outcome measures: The results were qualitative, not quantifiable.

Results: The sAC immunostaining produced distinctive patterns that paralleled melanomagenesis. At one pole of the spectrum were benign nevi, including atypical nevi of special sites and recurrent nevi showing a distinct pattern of dotlike Golgi staining, while at the opposite pole was melanoma, in which many cells demonstrated an intense pannuclear expression pattern, often accompanied by loss of the Golgi expression pattern. Melanomas of lentigo maligna and acral lentiginous subtypes exhibited the most striking pannuclear expression, while nodular melanomas showed the least, although with supervening enhanced diffuse cytoplasmic expression. Loss of the Golgi expression pattern was a feature of malignant melanoma.

Conclusion: The sAC expression pattern is complex but seems discriminatory, with distinctive and variable staining patterns according to the nature of the lesion biopsied.

Figure 1

Benign dermal nevus with soluble adenylyl cyclase (sAC) immunostain and hematoxylineosin costain. The sAC immunostaining pattern (red) is characterized by small dotlike Golgi positivity (arrow) around the nucleus; pannuclear staining is not observed. Weak incomplete granular nuclear staining is sometimes present. Scale bar, 25 μm.

Figure 2

Acral lentiginous melanoma with soluble adenylyl cyclase (sAC) immunostain and hematoxylineosin costain. The sAC immunostaining pattern (red) demonstrates extensive pannuclear staining of melanocytes (arrow) within the epidermis, highlighting the atypical melanocytes in a lentiginous and pagetoid array. Discernible Golgi staining is not apparent. Scale bar, 100 μm (A) and 75 μm (B).

Figure 3

Lentigo maligna melanoma. A and B, Central tumor with soluble adenylyl cyclase (sAC) immunostain and hematoxylineosin costain. The sAC immunostaining pattern (red) demonstrates extensive pannuclear staining of melanocytes (arrow in A) within the epidermis and dermis. A broad Golgi pattern is seen (arrow in B). C and D, Negative (C) and positive (D) margins with sAC immunostain (red) and hematoxylineosin costain. C, Benign photoactivated melanocytes exhibiting a perinuclear dotlike Golgi pattern are noted at the negative lateral margin of resection. D, In contrast, striking pannuclear staining of malignant melanocytes is present at a positive inked margin of resection. Scale bar, 75 μm (A), 50 μm (B), 25 μm (C), and 25 μm (D).

Figure 4

Malignant melanoma of superficial spreading subtype. A, B, and C, Soluble adenylyl cyclase (sAC) immunostain and hematoxylineosin costain show different morphologic structures of melanoma. The sAC immunostaining pattern (red) demonstrates fairly extensive pannuclear staining within the epidermis. C, There is focal pannuclear staining amid neoplastic cells in the dermis (arrow A). Some nuclei are devoid of staining (arrow B). There is conspicuous nucleolar staining (arrow C). A noticeable lack of Golgi staining is apparent. Scale bar, 75 μm (A), 100 μm (B), and 50 μm (C).

Figure 5

Nodular melanoma showing soluble adenylyl cyclase immunostain and hematoxylineosin costain. A, B, and C, All 3 panels show striking pannuclear staining. Golgi staining is present in a few cells. There is diffuse intense cytoplasmic staining. Scale bar, 75 μm (A), 50 μm (B), and 50 μm (C).

Figure 6

Capsular nevus showing soluble adenylyl cyclase (sAC) immunostain and hematoxylineosin costain. The sAC Golgi staining pattern (red) is noted around the nucleus, and there is occasional incomplete granular nuclear staining. Pannuclear staining is not identified. Scale bar, 50 μm.

Figure 7

Metastatic melanoma in the lung showing soluble adenylyl cyclase (sAC) immunostain and hematoxylineosin costain. Images A, B, and C increase in magnification. The sAC immunostaining pattern exhibited extensive pannuclear staining without cytoplasmic staining. Scale bar, 100 μm (A), 100 μm (B), and 50 μm (C).