Fig. 11.9 Keratinizing squamous cell carcinoma of the vulva. (A) Histopathologically malignant squamous eddies infiltrating superficially in the dermis
of the vulva (H&E x LP); (B) cytologically malignant squamous cells showing marked nuclear and cytoplasmic pleomorphism and atypical keratinized pearl
formation (Papanicolaou x HP).
Fig. 11.10 Extramammary Paget's disease. (A) Histopathologically enlarged mucin-containing Paget's cells proliferate through the full thickness of the
epidermis of the vulva (H&E xLP). (B) Cytopathologically Paget's cells have enlarged nuclei with intracytoplasmic mucin inclusions (Papanicolaou xHP).
appear as irregular, generally well-demarcated erythematous or
eczematous islands that frequently ulcerate. The labia majora
are the most frequently involved site. Progression to an inva-
sive carcinoma only rarely occurs. The prognosis depends on
whether an invasive carcinoma is present (20-30% of cases), as
well as the extent of the disease.36 Recurrences due to inapparent
histologic involvement of the margins of resection are frequent.
The prognosis for patients with underlying invasive carcinoma
and lymph node metastases is poor.37
Paget's disease histologically is characterized by the presence
of large, pale cells with mucicarmine-positive cytoplasm; they
are isolated or occur in aggregates in the epidermis (Fig. 11.10A).
Occasional signet-ring forms are noted. Involvement of the hair
follicles, pilosebaceous units, sweat ducts, and less frequently,
sweat glands may be observed. Invasion of the dermis may be
in the form of sheets, glands, or cords. Rarely, invasive carci-
noma may occur directly from the epidermis. Melanin granules
within Paget cells have been observed. The differential diagnosis
of Paget's disease includes pagetoid squamous cell carcinoma
in situ (Pagetoid Bowen's disease) and superficial spreading
melanoma. Ancillary stains may be needed to differentiate
between these two lesions.38,39 Cytologically, Paget cells are iso-
lated or occur in groups. The cells are large and contain variable
amounts of cytoplasm that stains indeterminately (Fig. 11.10B).
The nuclei are enlarged and usually eccentrically placed, and
occasional signet-ring forms are observed.2 One or more nucle-
oli are generally present. "Cell-within-cell" groupings are said to
be characteristic.40,41 Distinction of the cytologic characteristics
of Paget's disease lesions from those having underlying invasive
adenocarcinoma has not been possible.
Key features of Paget's disease in vulvar scrape
• Isolated cells or in small groups;
• Variable amount of cytoplasm;
• Enlarged, usually eccentrically placed nuclei;
• Occasional signet-ring forms;
• One or more nucleoli; and
• "Cell-within-cell groupings"