- Human pathology

Home > E. Pathology by systems > Skin > nodular hidradenoma

nodular hidradenoma

Friday 28 August 2020

hidradenoma, eccrine acrospiroma, clear cell hidradenoma


Definition: Benign dermal nodule of eccrine /apocrine gland derivation.

Well circumscribed, lobulated / cystic mass with variably sized nests and nodules.


- nests / lobules of cells resembling eccrine poroma with either clear cytoplasm or prominent squamous metaplasia
- possible marked vascularity
- small and large lumina are lined by cuboidal ductal cells or columnar secretory cells
- cystic spaces may be due to degeneration of tumor cells
- Well circumscribed, no dermal connection.
- Solid/cystic areas of poroid and squamoid cells.
- Ducts and eosinophilic cuticle in the solid areas.
- No prominent cytological atypia, necrosis or mitosis.



- clear cell hidradenoma

- cystic hidraenoma

- Clear cell nodular hidradenoma involving the lymphatic system


- oncocytic nodular hidradenoma

- Nodular and cystic apocrine hidradenoma with mucinous metaplasia

Differential diagnosis

- cutaneous metastasis / metastatic disease

- aggressive digital papillary adenocarcinoma

- apocrine mixed tumor
- glomus tumor (different staining pattern)
- primary skin tumors with follicular differentiation
- tumors with sebaceous differentiation
- tumors with sweat gland differentiation

- Metastatic renal cell carcinoma (i.e. thyroid, lung, renal)
- Basal cell carcinoma with eccrine differentiation:

  • Peripheral palisading and no cystic areas

- Hidradenocarcinoma:

  • Greater cytologic atypia, mitoses and infiltrative

- Squamous cell carcinoma:

  • Epidermal connection, keratin pearls and infiltrative
  • Absence of secretory differentiation

- Trichilemmoma:

  • Broad connection with the epidermis
  • CD34, thickened hyalinized basement membrane and peripheral cell palisading

- Poroma:

  • Epidermal connection and broad, anastomosing cords
  • Poroid cells, cuticle lined ducts and recurrent YAP1-MAML2 and YAP1-NUTM1 fusions identified in a subset
  • Preliminary data suggest that poroid hidradenoma may be more closely related to poroma than nodular hidradenoma (J Clin Invest 2019;129:3827)

- Cylindroma:

  • Jigsaw puzzle pattern
  • Hyaline globules and thickened basement membranes

See also

- cutaneous adnexal tumors

  • Diagnosis of adnexal tumors